**6. Background**

To make the argument of this study more sounding, the Freedom Charter of 1995, from which all the promises were made by the liberation movements particularly with regards to land and governance will shed very important light for the cause of the frustrations that South Africans are having today. Three specific statements in the Freedom Charter are:

The Land Audit Report of November 2017 continued to emphasize by quoting the Constitution of the Republic by saying: "South Africa belongs to all who live in it, united in our diversity" [18]. The gist of this paper may be complicated for some readers without the knowledge of the Freedom Charter, which was a helping tool for the governing party and other liberal movements to gain the support of the majority in toppling the apartheid regime. It is on the background of these initial promises adopted in 1955 that the reactions of people on issues of land in South Africa can be attributed to.

There is a confirmation that the 2017 Land Audit Report stats on land reform were just a beginning of the long journey of redistributing the land by saying: "Finally, this exercise has revealed that we have just taken the first steps upon a long journey towards the goal of the sustainable relationship of South African citizens to one another through the effective management of land as a resource and nationbuilding"([19], p. 20).

According to ([20], p. 1) the land restitution programme which is based on Section 25(7) of the *Constitution,*1 points that:

*Land Redistribution: A Thorny Issue towards Reconciliation in a Post Apartheid South Africa… DOI: http://dx.doi.org/10.5772/intechopen.104380*

*"A person or community dispossessed of property after 19 June 1913 as a result of past racially discriminatory laws or practices is entitled, to the extent provided by an Act of Parliament, either to restitution of that property or to equitable redress." Some of the claims in this regard were attended to, but many are still outstanding and the landless are not aware of what the update is.*

The state of affairs according to "The Borgen Project report" with regards to land occupation as in 2021 indicates that: "White South Africans accounted for less than 10% of the population after the apartheid in South Africa ended in 1994. However, 90% of white South Africans owned the land. In addition, about 72% of white South Africans owned farmland in 2017. Meanwhile, black South Africans owned only 4% of land and Indian South Africans owned about 5%. As such, poverty and land reform in South Africa remain large issues ([21], p. 1). This audit is supported by Phaliso [22] who exactly have the same statistics in his/her report dated 2018. The audit shows that whites owned the majority of land at 72%, followed by coloured people at 15%, Indians at 5% and Africans at 4%.

Until today, South Africa is still one of the countries with the highest levels of inequalities, according to World Bank 2019 statistics [23]. The disparities that exist between the rich and the poor is incomparable to most of the countries. From then onwards, the ownership of the land in the country was transferred into White hands, that continued even during the apartheid period [24]. The Natives Land Act which is regarded as apartheid's original sin saw thousands of black families being forcefully removed from their land and since then onwards, black South African knew no peace with regards to those removals.

The continued removal of black people from the land went on even when homelands were formed in the late 1960s and became is a crack that has not yet mended even after close to three decades of democracy. The forceful removal of black ethnic groups aimed at giving some land for exclusive use had been and will always be blamed for the current inequalities. There is no doubt that the move to democracy in South Africa is challenged among others by the land reform process. This is because some effects of the apartheid regime were the historical unequal allocation of the land ([25], p. 1). These historical injustices should be dealt with for true reconciliation to surface. The truth which is undeniable, according to De Villiers [26] is that in four countries namely; Zimbabawe, Namibia, South Africa and Australia the historical land issues were characterised by the inequality, colonial dominance and discrimination which led to the indigenous inhabitants being forced off their land to the benefit of white settlers, even the ancestral lands where they buried their loved ones were forcefully taken from them. It is an undeniable fact that by whom and how the land is used has a very direct bearing on the growing unemployment as well as poverty statistics [27].

My background discussion starts with a quote by Butjwana Seokoma [28] who said:

*"South Africa's land reform programme, adopted by the African National Congress (ANC) led government in 1994, has a long way to go in redressing the historical injustice of land dispossession, denial of access to land and forced removals."*

It is evident that the problem about land redistribution in South Africa was caused by the attitude of the racial discrimination of the apartheid government, which most of us accept was inclusive of many policies that wronged our people to a great extent. This is when all tribal laws, tribal divisions and forceful removal of blacks from the areas designated for white use exclusively. The dispossession of land from black

South Africans was a key part of the colonial and apartheid strategy of entrenching superiority over the black population, it rendered the blacks unable to live on their land, forcing them to work for the colonial and apartheid powers. It removed people from ancestral land, disabling them from being able to perform cultural rites, visit graves, bury the umbilical cords of newborns and the deceased on ancestral land [29].

Sol Plaatjie, the first secretary of ANC, was quoted reiterating what the colonial ideology was all about saying: "Where will we get servants if Kaffirs (Africans) are allowed to become skilled? A kaffir with a thousand bags of wheat? If they are inclined to her the pedigree stock, let them improve their masters (colonial settlers) cattle and cultivate for the owner of the land, not for themselves." (Motsoko [30]). Despite that the statement dealt a blow to the dignity and humanity of black people, this statement was manifested by ensuring that black people do not own land in this country; hence, the outcry today comes a long way.

 On the other hand, "those who were favoured through legislation to acquire productive and at the expense of the disposed black majority were able to use that asset over a time as a leverage for wealth creation- to get ahead materially, to afford the comforts of life, to take their children to better schools, to build social resilience and to bequeath material legacy for future generations of their kin. The experience of the black majority was the complete opposite"(Daily Maverick, 14 August 2018).

It is the acknowledgement of all these wrongs that were supposed to be accompanied by a confession of guilt from those who intentionally benefited from this wrongdoing. From the inception of democratic government in 1994 this had been one of the slowest projects of transformation, since only a small percentage of land had been taken so far. The resistance and politicising of this aspect caused delays that see us loosing lives like in the apartheid regime, for instance people whose shacks are being washed away by floods due to lack of proper space to shelter themselves.

No one can deny that the dawn of the first democratic elections in 1994 was harnessed among others by the hope that the disadvantaged people of this country thought that it would change their lives, even in terms of having land to themselves. The honest response is that very little had been done and this, on its own, does not give courage that the ordinary citizens of this country will have land from the country of their birth. The dignity of the other is continuously delayed and denied.

Mr Petros Nkosi said:

*"The land, our purpose is the land: that is what we must achieve. The land is our whole lives: we plough it for food, we build our houses from the soil, we live on it, and we are buried on it. When the whites took our land away from us, we lost the dignity of our lives, we could no longer feed our children, we were forced to become servants, we are treated like animals.  We must unite together to help each other and face boers. But in everything we do we must remember that there is only one aim and one solution and that is the land, the soil, our world." (18 May 2017), The constitutional court speaks about land and dignity). This is very similar to SAHRC's position on land reform when they said: "Land is dignity and the restitution of land rights equals to restoration of dignity."*

This is the kind of the enmity and hatred that had been sowed by the issue of land, among others. We cannot continue blinding ourselves to think Mr Nkosi's mind is

#### *Land Redistribution: A Thorny Issue towards Reconciliation in a Post Apartheid South Africa… DOI: http://dx.doi.org/10.5772/intechopen.104380*

his alone, since many black landless people are singing the same tune although they might not be very vocal. The dignity of a human being is on the land issue from birth to death. The previous state president Jacob Zuma also sang the same song of saying that it will be very difficult if not impossible to achieve true reconciliation until the land question is resolved ([2], p. 2).

If lack of land affects the dignity of the majority of this country, it means that by delaying and trying to avoid a quick movement towards it is also to deny that these people's dignity must be returned to them. Justice delayed is justice denied. Therefore, how do we expect of the landowner to be reconciled to someone who does not even own a space where his/her shack is situated. It is the dignity of our people that is being tarnished by red ants who are evicting them from one place to the next on a daily basis. If my shack cannot give me enough privacy because there is no space between it and those of my neighbours , while the white farmer has enough space even for his dogs, cats and mice to play around, then the dignity of the one living in the shack cannot be equated to the dignity that the dogs and cats have. How is reconciliation possible? Parker ([31], p. 3) is very correct to mention that returning the land means restoring the dignity of the people. It should however be commended that one of the first steps towards land restitution began after the unbanning of liberation movements during the last days of the National Party's rule in which FW De Klerk 's government abolished the Racially Based Land Measures Act 108 of 1991 where in a commission on land allocation was established ([26], p. 47). The situation as at 2019 according to [11] indicates that only 13% of South African is owned by black people while 87% of it is owned by whites.

We have two camps with regards to land issue in South Africa, those who have the land and the landless. Their walks of life, worldviews and life experiences still remain the same as it was more than twenty-five years ago; very opposed to each other and the question is: How do they join 16 December annual celebrations in the same fashion, while they remain in this situation? I am of the opinion that the reconciliation of people must not ignore the life world and levels of lives each person comes from. Some will people will argue that there are rich black people that own the houses that are on the first and second pictures, but I am fully aware that the majority of our people are still in the life indicated in the pictures below and yet they are not excluded from the discussions of reconciliation. To deal with and overcome the historical injustices of the past, where the land was seized under apartheid it is just imperative not to avoid addressing a land issue. That is what Gibson [24] in his book entitled Övercoming Historical injustices: Land Reconciliation in South Africa" is trying to argue. The land issue is undoubtedly at the heart of South African politics since it is an important cornerstone towards reconciling the nation that is haunted by racial divisions amongst others.

The first two pictures are of white farmers while the rest portray the living places for most black people living in South Africa.

The safety of the first two houses to natural disasters compared to the shacks in which one lives in fear, should high rainfalls come. This fear has been normalised to be a lived experience in which one is forced to create happiness despite circumstances.

in which most blacks spend four to five hours to reach and have their happiness there. An area that cannot have any resource at all, but life goes on as usual.

The above pictures confirm what Siviwe Feketa mentioned in his article entitled: South Africa world's most unequal society report' when he reported:

*The government has expressed disappointment with its track record of transforming the country after a World Bank report showed that inequality has deepened since the dawn of democracy, with the country being the most unequal society. The results of the probe, which assessed poverty and inequality from 1994 to 2015, revealed that only one in four South Africans could currently be stably considered as either middle class or upwards in terms of means [32].*

In Collins' article entitled: "No vacant land in Joburg is safe from occupation," he quoted one landless person in Alexander Township saying: "The empty stand represents an opportunity for dignity, privacy and a home she can finally call her own. It also represents a waste of something she has never had and is ready to fight for." [33]. This is one example out of many or even the majority of the people in South Africa, whose dreams to have a land of their own in which they can build houses is a dream not coming true. It is difficult to imagine that for almost three decades after the democratic government which had one of its pillars in the freedom charter as to ensure that all people will access the land.

Many other issues can be raised by just comparing these pictures, but for reconciliation's sake, there are many issues that would have to be attended to before we embark on the language of reconciling the two groups of people, unless the word reconciliation is only on our lips**.** Even though it is not the focus of this article, it is important to note that there are also squatter camps where white people are living, for instance, Munsieville in Krugersdorp. But it should however be known that this has been and

*Land Redistribution: A Thorny Issue towards Reconciliation in a Post Apartheid South Africa… DOI: http://dx.doi.org/10.5772/intechopen.104380*

is still a home for the majority of black South Africans. This has been part of the long history of inequality that was orchestrated by the elements of injustice and racism, among others. Recently, the very hot land debate was revived between the ruling party (ANC) and EFF where the bone of contention was that the government must be a custodian of the whole land while the ANC believed that they want to be custodians only of certain portions of the land in the country [34]. This of course have a close relationship with the argument of appropriation of land without compensation, which has been a headache for the government for a long time now. Of course, this very long debate is not of much interest in this study, but it is touched upon just to shed light as to where we are in terms of land ownership in South Africa, which has serious and should seriously continue to be one of the determining factors towards reconciling this very divided country.


**6.2 Recombinant mammalian/human lipases**

Owing to rapid development of plant biotechnology in recent times, Merispase a recombinant mammalian gastric lipase was produced in transgenic corn by Meristem Therapeutics and proposed as new oral substitute for the treatment of pancreatic insufficiency. Dog gastric lipase was selected because it is naturally resistant to inactivation by stomach acids and maintains a high enzymatic activity after passage through the stomach. Enzyme expression was stable over 11 generations with an approximate level of 1,000 mg kg-1 kernel (Shama & Peterson, 2008). According to Fieker et al. (2011), this approach could be problematic for several reasons: gastric lipase specific activity is about 10 times lower than that of pancreatic lipase (measured on tributyrin), it is highly sensitive to trypsin proteolysis, and endogenous secretion of gastric lipase can be increased in patients with pancreatic insufficiency because of possible nutritional adaptation. Meanwhile, clinical trials showed that the recombinant gastric lipase is well tolerated and efficient when administered either alone or combined with porcine pancreatic extract to patients with cystic fibrosis (Fieker & al., 2011, as cited by Lenoir et al., 2006, 2008). The highest efficiency is obtained when 250 mg of recombinant gastric lipase is associated with low dose of pancreatic extract (Fieker & al., 2011, as cited by Lenoir et al., 2008). Despite these encouraging results, Mersitem therapeutics went out of business in September 2008 while the product was blocked in clinical phase II trial.

Expected to offer superior safety by decreasing the risk of allergic reactions, recombinant human bile salt- stimulated lipase was suggested as promising candidate for the treatment of lipid malabsorption in pancreatic insufficiency. Human bile salt-stimulated lipase is naturally acid resistant and able to: (i) hydrolyze triglycerides and phospholipids (Lindquist & Hernell, 2010) (ii) generate lysophospholipids necessary for an efficient lipid absorption rate by the small intestine (Fieker & al., as cited by Tso, 1994) (iii) participate in chylomicron assembly and secretion through its ceramidase activity (Hui and Howles, 2002). For these reasons, Swedish Orphan Biovitrum - a leading company focused on treatment of rare diseases developed two preparations of recombinant bile salt-stimulated lipase: Kiobrina for preterm infants and

 (NDA) to ensure consistent efficacy, safety, and quality of these agents (US Food and Drug Administration, 2006). Therefore, in order to comply with the FDA 2004 mandate, several studies have been recently conducted to ensure safety and effectiveness of some new reformulated pancreatic enzyme supplements such as Creon® 24,000 and EUR-1008 (Zenpep™) (Wooldridge & al., 2009; Trapnell & al., 2009). Nevertheless, these products of animal origin present yet a risk of viral transmission. Accordingly, there remains a need for

Even though bovine enzymes have been suggested as a potential alternative for individuals who refuse to consume porcine products for religious or other cultural reasons; there remain some safety concerns about transmittable pathogens such as Foot and mouth disease and Bovine spongiform encephalopathy from these preparations. Additionally, lipase activity is

Owing to rapid development of plant biotechnology in recent times, Merispase a recombinant mammalian gastric lipase was produced in transgenic corn by Meristem Therapeutics and proposed as new oral substitute for the treatment of pancreatic insufficiency. Dog gastric lipase was selected because it is naturally resistant to inactivation by stomach acids and maintains a high enzymatic activity after passage through the stomach. Enzyme expression was stable over 11 generations with an approximate level of 1,000 mg kg-1 kernel (Shama & Peterson, 2008). According to Fieker et al. (2011), this approach could be problematic for several reasons: gastric lipase specific activity is about 10 times lower than that of pancreatic lipase (measured on tributyrin), it is highly sensitive to trypsin proteolysis, and endogenous secretion of gastric lipase can be increased in patients with pancreatic insufficiency because of possible nutritional adaptation. Meanwhile, clinical trials showed that the recombinant gastric lipase is well tolerated and efficient when administered either alone or combined with porcine pancreatic extract to patients with cystic fibrosis (Fieker & al., 2011, as cited by Lenoir et al., 2006, 2008). The highest efficiency is obtained when 250 mg of recombinant gastric lipase is associated with low dose of pancreatic extract (Fieker & al., 2011, as cited by Lenoir et al., 2008). Despite these encouraging results, Mersitem therapeutics went out of business in September 2008 while

Expected to offer superior safety by decreasing the risk of allergic reactions, recombinant human bile salt- stimulated lipase was suggested as promising candidate for the treatment of lipid malabsorption in pancreatic insufficiency. Human bile salt-stimulated lipase is naturally acid resistant and able to: (i) hydrolyze triglycerides and phospholipids (Lindquist & Hernell, 2010) (ii) generate lysophospholipids necessary for an efficient lipid absorption rate by the small intestine (Fieker & al., as cited by Tso, 1994) (iii) participate in chylomicron assembly and secretion through its ceramidase activity (Hui and Howles, 2002). For these reasons, Swedish Orphan Biovitrum - a leading company focused on treatment of rare diseases developed two preparations of recombinant bile salt-stimulated lipase: Kiobrina for preterm infants and

approximately 75% lower than the porcine preparations (Layer and Keller, 2003)

new alternatives to treat correctly exocrine pancreatic insufficiency.

**6. Enzyme replacement therapy: What's in the pipeline?**

**6.2 Recombinant mammalian/human lipases**

the product was blocked in clinical phase II trial.

**6.1 Bovine enzymes**

Exinalda for cystic fibrosis patients. A phase I clinical trial showed that addition of recombinant bile salt-stimulated lipase to standard pancrelipase (Creon) enabled a dose reduction of pancrelipase. The treatment had the advantage of restoring a normal level and pattern of plasma chylomicron secretion (Fieker & al., 2011, as cited by Strandvik et al., 2004). The combined results from two Phase II studies evaluating Kiobrina in preterm infants demonstrated an increase in growth velocity and uptake of long chain polyunsaturated fatty acids such as docosahexanoic acid and arachidonic acid. The safety and tolerability profile of rhBSSL added to formula was similar compared to placebo (Maggio et al., 2010). Based on these encouraging results, Swedish Orphan Biovitrum enrolls in August 2011 the first patient in Kiorbina phase III clinical trial. An open-label exploratory phase II study on Exinalda (rhBSSL) in patients with cystic fibrosis and pancreatic insufficiency has been completed.  The results showed that Exinalda is safe and tolerable at a dose level of 170 mg three times a day. In terms of efficacy (coefficient of fat absorption CFA) the primary endpoint was not met. Swedish Orphan Biovitrum is now assessing options to continue the development (Swedish Orphan Biovitrum website www. sobi.com).


**8.2 Autogenous vaccine against** *S. aureus* **mastitis**

These vaccines are the preparations having specific strains of bacteria obtained from mastitis suffered by animals and used to immunize the herd for protection against further new udder infections with the same strain of bacteria. There are evidences which shows that the use of autogenous *S. aureus* vaccines enhances antibody titer in vaccinated animals as compared to non-vaccinated herd and reduce the risk of both clinical and sub-clinical mastitis [71]. Some studies also show that autogenous vaccines provide almost 70% protection from infection and provide protection from clinically ill mastitis cases challenged with *S. aureus* [80].

Early studies suggest that vaccines for *S. aureus* will increase cure rate and lower SCC but in actuality, it does not work against adult cows. Experimental success was also seen with commercial *S. aureus* vaccine Lysigin® in the young dairy animals. When serum samples from vaccinated animals were checked they showed higher antibody titer as compared to non-vaccinated animals to combat against *S. aureus* infections [71]. So experimental and commercial preparations of *S. aureus* vaccine

provide protection against mastitis. Efficacy of these preparations against *S. aureus* ranges between 44%–66% and this strategy for prevention of *S. aureus* in the future, some new antigens and adjuvants are added to the vaccine preparations to enhance their effectiveness [72, 84].

#### **8.3 Vaccine response in vaccinated dairy animals**

*Staphylococcus aureus* is a predominant organism causing mastitis in different species. So, different experiments were conducted in different animal species to determine vaccine efficacy. The production and implementation of *S. aureus* vaccine in milk animals has a great impact towards public health. Inactivated vaccine was prepared and checked by using different adjuvants against *S. aureus* [85].

She camel having sub-clinical mastitis, vaccinal isolates were taken from her having alpha and beta hemolysin toxin, also some were multidrug resistant. Inactivated alum precipitated *S. aureus* vaccine (APSV) and oil adjuvant *S. aureus* vaccine (OASV) were prepared after confirming its antigenicity in rabbits. Experiments showed that APSV and OASV were safe, effective and expressed immunogenic responses in experimental rabbits [86, 87].

*S. aureus* is a major cause of mastitis in dairy cows causing mild to severe and chronic infections having drastic effects on cow's wellbeing, lifespan and milk production. Irrespective of years of research on mastitis issues still there is no production of an effective vaccine against *S. aureus mastitis.* Experimental studies showed that it's possible to vaccinate *S. aureus* naïve cattle and also this experimental immunization leads to humoral immune response which is different from response that occurs after natural exposure [79, 88].

Experiments are still in progress for the use of vaccine against *S. aureus* mastitis in small ruminants. Still, there is gap in using mastitis vaccine for prevention of *S. aureus* mastitis which is a major issue in dairy industry and causes huge economic losses every year. Perhaps there might be bright future for farmers because trails of mastitis vaccine in lab animals are showing satisfactory results, which is a hope [43, 50].

#### **8.4 Vaccine success rate**

Mastitis is one of the most dangerous disease of dairy industry. Vaccination and other managemental practices are the tools to prevent mastitis caused by contagious as well as environmental pathogens. The success rate of immunization depends upon type of vaccine, adjuvant used and route of administration of vaccination regardless of type of vaccine, only vaccine is not enough in the large herds with high mastitis cases. For achieving success, it is necessary to use up to date manage mental practices along with vaccine and culling of chronically ill cases to reduce intra mammary infections [50, 89].

Experiments conducted from last 15 decades show that experimental *S. aureus* vaccines as well as commercial vaccines reduce new infections in dairy heifers. *S. aureus* vaccine was prepared by focusing on two major components of *S. aureus* (pseudo-capsules and alpha toxins). 2 and 4 weeks before calving heifers were given injections in the supra-mammary lymph node of mammary glands. Injections were given subcutaneously. After caving these heifers were challenged with *S. aureus* infections. These heifers showed 46% reduction in *S. aureus* infections as compared with control group of animals. There was almost 70% success rate from infection in vaccinated animals and less than 10% in non-vaccinated animals. Clinical signs of mastitis were also mild in vaccinated herds compared to control group of animals [6, 72].


3.1.3. X-ray Diffraction Spectroscopy

The XRD patterns varied in peak intensity and width according to the reducing/capping agent used. In general, the peak widening could be observed for all the six types of synthesized ZnNPs which represents the nano-scale crystalline size of the prepared ZnNPs. The XRD peaks obtained showed close agreement with the characteristic Bragg peaks of hexagonal ZnO zincite (pattern: PDF 00-036-1451), and hydro-zincite (pattern: PDF 01-072-1100). Mixed crystal phases including the simonkolleite (pattern: COD 9004683) along with zincite and hydro-zincite specific peaks can be identified in ZnNMs derived from ZnCl2 salt as substrate (Figure 4). The use of starch as a reducing agent resulted in the formation of nanoscale hydrozincite crystals. While Starch (CA) ZnNPs had both zincite and hydrozincite as the predominant crystal phases. This variation may be attributed to the use of NaOH as a reducing agent during the synthesis of the Starch (CA) ZnNPs. Cellulose (CA) ZnNPs possessed a mixed crystal phase with simonkolleite as one among the predominant crystal structure. As indicated above, it can probably be due to the use of a high concentration of zinc chloride (65 wt %) as the precursor salt for the synthesis of ZnNPs.

**Figure 4.** X-ray diffraction spectroscopy of the synthesized ZnNPs depicting the formation of wurtzite hexagonal crystal structure zincite (ZnO) on the use of various reducing and capping/complexing agents i.e., Sodium hydroxide (RA), Thiourea (RA), Starch (RA), Bovine serum albumin (CA), Starch (CA), and Cellulose (CA).


**5.3 Core MBK processes to capitalize on company's knowledge**

The core MBK processes answer the problem of capitalization on company's knowledge. Thus, we have identified four core MBK processes corresponding to the resolution of the categories of problems: locating core MBK process, preserving core MBK process, enhancing core MBK process, and actualizing core MBK process. Each of these core processes contains sub-processes designed to solve all the problems involved. These sub-processes are integrated into the overall management based on knowledge processes implemented in the organization.

We describe these processes below.

The following description of the core MBK processes is not necessarily cyclical in nature. Each category contains, in itself, a set of problems that can be addressed in a different order depending on the situation and context of each organization.

[48]. When formalizing knowledge is not feasible, then interactions of people through social networks, communities of practice, or other types of networks implemented, and the transfer of master-apprentice-type knowledge should be encouraged.


Hirohide Sawada1,2, Hiromi Suzuki3, Kenji Ono3, Kazuhiro Imamura4, Toshiharu Nagatsu2,3 and Makoto Sawada3

*1Department of Medical Technology, Kobe Tokiwa University, 2Department of Pharmacology, School of Medicine, Fujita Health University, 3Department of Brain Life Science, Research Institute of Environmental Medicine, Nagoya University, 4Department of Neurology, Okazaki City Hospital, Japan*


*Article* **Microgrid Operations Planning Based on Improving the Flying Sparrow Search Algorithm**

**Trong-The Nguyen 1,2, Truong-Giang Ngo 3,\*, Thi-Kien Dao 1,\* and Thi-Thanh-Tan Nguyen 4**

	- **\*** Correspondence<EMAIL_ADDRESS>(T.-G.N<EMAIL_ADDRESS>(T.-K.D.)

**Abstract:** Microgrid operations planning is crucial for emerging energy microgrids to enhance the share of clean energy power generation and ensure a safe symmetry power grid among distributed natural power sources and stable functioning of the entire power system. This paper suggests a new improved version (namely, ESSA) of the sparrow search algorithm (SSA) based on an elite reverse learning strategy and firefly algorithm (FA) mutation strategy for the power microgrid optimal operations planning. Scheduling cycles of the microgrid with a distributed power source's optimal output and total operation cost is modeled based on variables, e.g., environmental costs, electricity interaction, investment depreciation, and maintenance system, to establish grid multiobjective economic optimization. Compared with other literature methods, such as Genetic algorithm (GA), Particle swarm optimization (PSO), Firefly algorithm (FA), Bat algorithm (BA), Grey wolf optimization (GWO), and SSA show that the proposed plan offers higher performance and feasibility in solving microgrid operations planning issues.

**Keywords:** microgrid; distributed power supply; enhanced sparrow search algorithm; economical operation


**1. Introduction**

Cranio-maxillofacial defects related to tumors, traumas, infections, or congenital deformities are highly challenging tasks for oral and maxillofacial surgeons to reconstruct [1,2]. When bone losses are too severe for human body routine mechanisms to regenerate, autologous grafts are the first considerations due to the simultaneous osteogenic, osteoinductive, and osteoconductive properties [3]. However, the shape of the donor sites, bone graft resorption, and infection restrict the application of autografts [4]. Currently, the most popular orthopedic/dental artificial materials are metals like titanium (Ti) and its alloys. These materials have many advantages, such as excellent biocompatibility, corrosion resistance, and mechanical strength [5]. However, there are some critical drawbacks of Ti, one of which is stress-shielding, which may occur at the interface between Ti and bone during load

transfer and result in surrounding bone loss [6]. In addition, the radiopacity of Ti alloys in the CT and MR scan images and the release of harmful metal ions hinder the application of metals [7]. Due to the limitations observed in metallic biomaterials, polymers have been explored in recent years as potential alternative materials for bone replacement.

In the last few years, polyether ether ketone (PEEK) has been investigated widely in oral and cranio-maxillofacial surgery. Possible applications are dental implants, skull implants, osteosynthesis plates, and bone replacement material for nasal, maxillary, or mandibular reconstructions (Figure 1) [8–11]. PEEK is considered an alternative material for Ti due to its excellent biocompatibility, radiolucency, chemical resistance, low density (1.32 g/cm3), and mechanical properties resembling human bone. PEEK is a polyaromatic semi-crystalline thermoplastic polymer with an elastic modulus of 3–4 GPa (Table 1), which is much lower than that of Ti (102–110 GPa) and very close to the human trabecular bone (1 GPa) [8,12]. Moreover, the mechanical strengths of PEEK can be enhanced by the incorporation of other materials (e.g., carbon fibers) [8]. Normally, carbon fiber reinforced polyether ether ketone (CFR-PEEK) has an elastic modulus close to the human cortical bone (14 GPa), depending on the amount of reinforced carbon fiber and manufacturing methods. CFR-PEEK is considered as a promising candidate to replace metallic materials because of the inherited advantages of PEEK and improved mechanical properties [13,14].

**Figure 1.** (**a**) Clinical applications of PEEK; Fused deposition modeling (FDM)-printed PEEK (**b**) breastbone and (**c**) nasal reconstructions.

**Table 1.** The elastic modulus of different materials and human tissues.

Additive manufacturing (AM) is a layer-by-layer manufacturing method, fabricating specimens by fusing or depositing materials, such as metals, ceramics, plastics, or even living cells [16]. This technique is becoming popular in orthopedic surgery for fabricating patient-specific implants due to the low cost, the feasibility of complex architectures, and the short production time [17]. Selective laser sintering (SLS) has been the most popular AM technology for fabricating PEEK in the past decades [18,19]. Compared with SLS, fused deposition modeling (FDM) is one of the fastest growing three-dimensional (3D) printing methods due to the lower costs, easier use (filament vs. powder), and reduced risk of material contamination or degradation. Furthermore, it has increasingly been applied to the manufacturing of PEEK and its composites in recent years [20]. However, due to the semicrystalline structure and high melting temperature of PEEK (compared with other FDM filament materials like polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS)), it is difficult to process PEEK objects by FDM printing and the process is liable to cause excessive thermal stress and thermal cracks [8,18]. Yang et al. and Wu et al. have already measured the mechanical properties of FDM-printed pure PEEK and found that compared with some traditional manufacturing methods (i.e., injection molding), FDM-printed PEEK had lower mechanical strengths, which were influenced by layer thickness, printing speed, ambient temperature, nozzle temperature, and heat treatment [21,22] FDM-printed PEEK composites, to the best of our knowledge, have not yet been studied.

Compared with Ti, the unmodified PEEK is bioinert and has limited osteoconductive properties, which may influence the osseointegration after implantation [23,24]. Surface topographical modification is one of the mechanical surface modification methods to increase the biological performance of cranio-maxillofacial implants [25]. Surface roughness may influence cell adhesion, and a roughened surface usually has a more extensive surface area which offers more binding sites for cell attachment [26]. Some studies have already analyzed the influence of surface roughness on the bioactivity of PEEK and its composites [26–28]. However, in these reports, PEEK and its composites were all manufactured by traditional techniques like milling, injection modeling, and compression molding. For the FDMmanufactured PEEK, most studies only analyzed the manufacturing process and mechanical properties of pure PEEK, without PEEK composites [17,18,22]. According to our knowledge, tests of the mechanical properties of FDM-printed CFR-PEEK are still lacking. Therefore, the aim of this study was to evaluate the mechanical properties and microstructures of PEEK and CFR-PEEK samples manufactured by FDM. Specific attention was paid to the question of whether the FDM printing process has introduced or produced toxic substances and to the influence of surface treatments on the cell adhesion on sample surfaces.


*Article* **Laboratory Methods for Assessing the Influence of Improper Asphalt Mix Compaction on Its Performance**

### **Michał Wróbel, Agnieszka Woszuk and Wojciech Franus \***

Department of Geotechnical Engineering, Faculty of Civil Engineering and Architecture, Lublin University of Technology, Nadbystrzycka 40, 20-618 Lublin, Poland<EMAIL_ADDRESS>(M.W<EMAIL_ADDRESS>(A.W.)

**\*** Correspondence<EMAIL_ADDRESS>Tel.: +48-815-384-416

Received: 6 May 2020; Accepted: 26 May 2020; Published: 29 May 2020

**Abstract:** Compaction index is one of the most important technological parameters during asphalt pavement construction which may be negatively a ffected by wrong asphalt paving machine set, weather conditions, or the mix temperature. Presented laboratory study analyzes the asphalt mix properties in case of inappropriate compaction. The reference mix was designed for AC 11 S wearing layer (asphalt concrete for wearing layer with maximum grading of 11 mm). Asphalt mix samples used in the tests were prepared using Marshall device with the compaction energy of 2 × 20, 2 × 35, 2 × 50, and 2 × 75 blows as well as in a roller compactor where the slabs were compacted to various heights: 69.3 mm (+10% of nominal height), 66.2 mm (+5%), 63 mm (nominal), and 59.9 mm (−5%) which resulted in di fferent compaction indexes. Afterwards the samples were cored from the slabs. Both Marshall samples and cores were tested for air void content, sti ffness modulus in three temperatures, indirect tensile strength, and resistance to water and frost indicated by ITSR value. It was found that either insu fficient or excessive level of compaction can cause negative e ffect on the road surface performance.

**Keywords:** asphalt mix; compaction index; volumetric parameters; sti ffness modulus; moisture resistance


Implications of Land Use and Cover Changes on Upper River Rwizi Macro-Watershed Health in South Western Uganda

*Denis Nseka, Hosea Opedes, Frank Mugagga, Patience Ayesiga, Henry Semakula, Hannington Wasswa and Daniel Ologe*

### **Abstract**

The upper Rwizi river system in South Western Uganda has been severely degraded due to encroachment and unsustainable resource utilization. Little is, however, known about the link between the upper Rwizi macro-watershed health and land use/cover patterns from the spatiotemporal perspective. This study evaluated the relationship between spatiotemporal land use/ cover change and upper river Rwizi macro watershed health. Remotely sensed data was used to analyze the spatiotemporal land use and cover distribution for upper Rwizi macro watershed. The analysis was done using Landsat and Sentinel imagery datasets spanning 1990 to 2020 and 2016 to 2021 respectively. Field verification was undertaken to confirm the land use, cover types, and evaluate the implications of prevailing anthropogenic activities on the watershed health. The land use and cover characteristics in the upper Rwizi macro-watershed exhibits both highly spatial and temporal variations. By 1990, grassland as the dominant land use and cover type spanned 45% of the total study area followed by farmland at 30%. Forests, open water and settlements covered 12%, 10% and 3% respectively. Whereas grassland and forest cover has diminished drastically by 64% and 71% respectively, settlements and farmland have increased tremendously by 79% and 50% respectively between 1990 and 2020. The hillslope hydrological characteristics in the watershed are severely hampered due to increased human activities. It is, therefore, recommended that afforestation in the degraded areas be undertaken to restore the watershed health which could improve on hillslope hydrology.

**Keywords:** land use-cover changes, watershed health, river Rwizi

### **1. Introduction**

River systems are crucial for the Earth's landscape development [1]. They play significant roles in the provision of water for domestic and industrial purposes as well as a number of resources to communities [2]. Due to their favorable ecological characteristics associated with humid climate and fertile alluvial soils, most river systems have attracted dense populations [3]. The high population densities within river systems have come with increased human activities [4]. The land use dynamics continue to impact on river catchments with negative repercussions on such fragile ecosystems [5]. River catchments are profoundly impacted by land use and cover change driven by anthropogenic activities [6]. The impact of anthropogenic activities on the riverbank morphodynamic is manifested in two ways [7]. First directly, in form of regulation works, artificial cut-offs, gravel and sand exploitation, dam constructions among others. Secondly, it is manifested indirectly in the form of deforestation, social and economic activities in river catchments [5]. Intensive human activities can indirectly impact more dynamic changes of natural processes, which may alter river processes and their subsequent hydro – ecological services [8].

Land Use and Cover Change (LUCC) is a key driver of environmental problems in river valleys and their catchments [9]. Land uses such as forestry, croplands and settlements have transformed most river catchments [10]. Land use and human activities within a watershed can lead to alteration in landscape's hydrological properties [11]. The surface landscape is often fundamentally altered during economic and social development [1]. The quantity, morphology and structure of river systems are usually inadvertently influenced along with land use changes [4]. Estimating historical LUCC trends is essential in assessing the rate at which change occurs; permit exploration of the drivers of that change and related implications [12]. Due to LUCC implications on watershed degradation, impacts like decline in river water quality and quantity often take route [13]. Degraded watersheds have posed serious problems for the environment and people living within river environments [3]. Effective management of watersheds, therefore, requires an understanding of the hydro – ecological resource changes over time and space amidst human activities [14].

The Rwizi river system navigates through Ankole highlands in South Western Uganda providing a source of water and livelihood to people across the region [15]. At least 12 districts including Rakai, Lyantonde, Isingiro, Lwengo, Kiruhura, Mbarara, Bushenyi, Buhweju, Rwampara, Sheema and Rubirizi depend on Rwizi's water for both domestic and commercial use [16]. The Rwizi river system that covers approximately 8,200 km [15] is under serious threat and is on the verge of drying up due to degradation [17]. River Rwizi, which is a lifeline for more than five million people in southwestern Uganda [16] including over 400,000 people in Mbarara City [18], has had up to 80 percent of its water drying up [17]. In recent years, river Rwizi has been branded as a river on the brink of extinction due to climate change, human encroachment and unsustainable resource utilization [15]. Its degradation is not unique but a common challenge to all river systems around the country [19]. Poor land management on the riverbanks and buffer zone is partly responsible for its catchment degradation [20]. The rapid population growth in the region has significantly increased pollution and untreated effluent discharge into the river system [16], while increased demand for water is causing the river to dry up [17]. The destructive agricultural practices, population pressure and unsustainable activities taking place within the river's catchment areas have led to the deterioration of its water quality and quantity [20]. These challenges are now fueling increased socio-economic hardships for local residents that are now manifesting through increased poverty, and continuous water shortages leading to water rationing in the region [15]. These challenges are likely to be exacerbated by the impacts of climate change and continued biodiversity loss [21]. There is, however, particular dearth of information on the implications of LUCC on the ecosystem health of upper Rwizi macro watershed. This, therefore, calls for an urgent need to undertake a spatial –temporal LUCC analysis on the upper Rwizi macro watershed in order to evaluate the major drivers and related implications of this change.

*Implications of Land Use and Cover Changes on Upper River Rwizi Macro-Watershed Health… DOI: http://dx.doi.org/10.5772/intechopen.99611*

### **2. Methods and materials**

### **2.1 Study area**

The study was conducted in the upper Rwizi macro watershed within the Ankole highlands of South Western Uganda situated between latitude 0°360 0600S to 0° 480 8500S and longitudes 30°280 3000E to 30°590 6500E (**Figure 1**). River Rwizi originates from Buhweju hills with various tributaries from Ankore highlands and pours its water in Lake Victoria via the drainage systems of Lakes including Mburo, Kachera and Kijanebalola [17]. The upper Rwizi macro watershed was selected for a detailed study owing to increased degradation that is associated with spatiotemporal land use and cover distribution. The drainage network and topography served as baseline information for establishment of the study area and was delineated automatically from a 30 m Digital Elevation Model (DEM) in ArcGIS 10.5. Topographically, the landscape is a dissected plateau, variant of Koki land system characterized by long straight ridges [15]. The topography comprises mainly extensive flat-topped ridges and hills encircling down land arenas (**Figure 2**) typical of Ankole landscape [19]. The ridges have comb-like appearance due to many gullies on the landscape [22]. The geology of the area consists of a sedimentary rock system of the Precambrian age commonly referred to as Karagwe-Ankolean rock system. Quartz–mica and mica schists, shale, phyllite as well as swamp deposits and alluvium dominate this rock system. The soils of the highlands comprise acric ferralsols, dystric regosols, eutric regosols, gleyic arenosols, gleysols, histosols and leptoslos [20].

The study area experiences a bimodal rainfall pattern [16] with two wet and dry seasons [17]. The principal rainfall season is from late August to early December, while the minor one is from late February to mid-May [20, 21]. The average annual rainfall is 1000 mm per annum [23] however, mean annual rainfall can go as low as 750 mm in the eastern and as high as 1520 mm in western parts of the region [17]. There is a marked dry season experienced from June to August as well as January to

**Figure 1.** *Location of the study area indicating study sites.*

February [24]. More than a century ago, the highlands in the watershed were covered by natural vegetation from the crest to the valley bottom dominated by *Themeda Triandra* and *Hyparrhenia rufa* grass species [21] as well as tree species including *Vernonia ammygdalina*, *Acacia sieberriana*, *Acacia hockii, C. edulis* and *Albizia coriaria* [17, 20]. These have however, been colonized by *Londetia kagerensis* on some hillslopes. The valley bottoms are currently dominated by *I. cylindrica* and *Cymbopogan afronadus*/ lemon grass [19]. The vegetation cover is characterized by medium savannah grass with scanty elephant grass (*P. purpureum*). The population density (361/km2 ) of the region is one of the highest in Uganda [23] with its major source of livelihood being agriculture characterized by arable and livestock farming [16].

### **2.2 Datasets and sources**

Remotely sensed data was used to analyze the spatiotemporal land use and land cover distribution for upper Rwizi macro watershed in south western Uganda. The analysis was based on Landsat and Sentinel imagery data sets spanning 1990 to 2020 and 2016 to 2021 respectively. Landsat satellite imagery of 30 m spatial resolution (path 172 and row 060) were downloaded from the open source site- USGS Earth explorer (https://earthexplorer.usgs.gov/). A Key Hole Mark-up Language File (KML) for Rwizi macro-watershed was developed using Google earth and later exported to USGS to delineate the area of interest. Specifications were made about the cloud cover (less than 10%) and dataset requirements. Landsat scenes for 1990 were picked from Landsat 4–5 TM, while scenes for 2000 and 2010 were picked from Landsat 7 ETM+ level 1 archives. Landsat scenes for 2020 were picked from Landsat 8 OLI/TIRS (Operational Land Imager and Thermal Infrared Sensor) satellite. Selected scenes were dropped into the item basket in USGS and downloaded using the Bulk Download Application. The sorted scenes were then prepared in folders in windows files explorer for pre-processing.

### *2.2.1 Image processing and classification*

Landsat images for 1990, 2000, 2010, and 2020 and Sentinel 2 images for 2016 and 2021 were exported to ArcGIS 10.5, geo-registered to WGS 84 datum, and projected into the Universal Transverse Mercator (UTM) zone 36 N coordinate system. Before performing the final analyses, a series of processes were performed *Implications of Land Use and Cover Changes on Upper River Rwizi Macro-Watershed Health… DOI: http://dx.doi.org/10.5772/intechopen.99611*

on the downloaded images to improve visualization, processing speed as well as reducing noise. The nature of these processes necessitated swinging between two software packages of ArcGIS 10.5 and QGIS 2.18. The satellite scenes were loaded, visualized and inspected in the two software packages. Gap filling was, therefore, done to seal the existing gaps in the images. This was done in QGIS 3.4.2 using the fill NoData tool under the raster analysis tools provided by the GRASS plugin of open source software. The fill NoData tool which employs data from the gap masks provided by USGS to fill stripped zones on the scenes was done for 2010 image. Satellite imagery scenes downloaded contained the 'black NoData borders' which had to be discarded. This process was carried out in ArcGIS 10.5 utilizing the copy raster tool under the data management toolset. Using this tool, the NoData and background data values were set to zero. The first major pre-processing step performed was to create image composites for ease of visualization and interpretation of selected images. Formation of composites was done by stacking the eight bands of Landsat using the composite bands tool provided under the data management toolset of ArcGIS. Image composites for each path/row combination was done for each of the two scenes for the four selected years. Image composites were created by combining individual bands in a pre-determined pattern. This was done to enhance visualization but most importantly to capture different parts of the electromagnetic spectrum since different objects reflect in different parts of the spectrum. The band combination 432 was selected and used for creating the Red-Green-Blue image composites because it is the best band combination for visualizing and analyzing reflected vegetation [25].

### *2.2.2 Classification accuracy assessment*

In Ref. [26], overall, producer's and user's accuracies and Kappa coefficient were calculated from the error matrix. The accuracy of the classification was verified by randomly generated reference points using a stratified random algorithm [27]. Following [28, 29], a minimum of 100 random points were generated per class using stratified random sampling approach for accuracy assessment. Field verification for land use and cover classification was conducted between January and August 2020 using draft classified map derived from satellite image for 2020 as a guide. The field verified data were utilized in the maximum likelihood report as an independent data set from which classification accuracy was compared. The land use and cover images for 1990, 2000 and 2010 were validated using Google Earth images taken in November 1990, July 1999 and October 2009 respectively. Higher classification accuracies were obtained for all the downloaded images due to improved sensors. An overall accuracy ranging between 69% (1990) and 85% (2020) was achieved for the Landsat images. The Kappa coefficient accuracies ranged from 0.65 to 0.82 for 1990 and 2020 respectively.

### *2.2.3 Land-use and cover change detection*

Analysis of land use and cover changes was conducted in three temporal periods including, 1990–2000, 2000–2010 and 2010–2020. The satellite images had to be classified into five thematic classes namely settlements, farmlands, open water, forests and grasslands (Appendix 1). Supervised classification was performed in ArcGIS 10.5 using the maximum likelihood algorithm. The USGS Anderson classification scheme and class definitions were used to assign classes. Post-classification assessments were undertaken using majority filter, boundary cleaning and area calculation to clean the images. Post classification change detection technique was applied to identify the dynamic land use and cover

elements from the successive years of satellite data. Post classification was used since the respective imagery were captured using different Landsat sensors and, therefore, with spectral differences. Analysis of land use and cover changes was performed based on automatic comparison of image sub-object hierarchies ("For example, see [30]"). The change detection matrix was computed to determine the proportion of each class which experienced change during the observation period. The major land use and cover change trends were identified from maps generated. The level of persistence was established through a cross-tabulation matrix.

### *2.2.4 Land use and cover change detection from sentinel images*

Given the spectral characteristics of Landsat imagery, very high resolution images from Sentinel 2 were also used to evaluate the land use and cover changes within particular sections of the river system which could not be detected from Landsat images. Sentinel 2A images of spatial resolution 10 m spanning 2016 to 2021 of MSIL2A\_N0214\_R078\_T36MTE type for 01/05/2016 and 27/01/2021 respectively were acquired from the European Space Agency (ESA) website ((https://sentinels.copernicus.eu/web/sentinel/missions/sentine l-2), through the Sentinels Scientific Data Hub archive. Using the same search specifications as for Landsat, only 2016 and 2021 images were found in the Sentinel 2 hub for Mbarara sub-watershed. Cloud-free Sentinel 2A images covering Mbarara sub-watershed within upper Rwizi macro watershed were selected and downloaded for land use and cover change estimation. Mbarara sub-watershed within upper Rwizi macro-watershed (**Figure 1**) was identified as the most affected section by land use and cover changes over 30 year study period. The European Space Agency's (ESA) satellite constellations Sentinel 2 program was used to combine both high spatial and temporal resolution. The images were subjected to atmospheric correction effects using the Sentinel 2 Correction prototype processing tool in SNAP. The already ortho-rectified Sentinel 2 images were geometrically corrected in Universal Transverse Mercator projection and World Geodetic System (WGS) 84 ellipsoid. The overall accuracy for Sentinel 2 images was 90% for 2016 and 92% for 2021. The Kappa coefficient was 0.87 and 0.90 for 2016 and 2021 respectively. Like for the Landsat images, five thematic classes were generated from the Sentinel images (settlements, farmlands, open water, forests and grasslands) utilizing the USGS Anderson classification scheme.

### **2.3 Field investigations and surveys**

Before the interpretation of land use and cover maps, field investigations were undertaken between January and August 2020 to verify the actual land use and cover characteristics. Field verification was also undertaken to confirm whether the created maps lie within corresponding natural boundary. After field verification exercise, some correction was made in land use map before finalizing with the analysis. Additionally, survey data from local people and key informants living within Rwizi macro-watershed was collected to better understand and interpret the LUCC scenarios that emerged from the remote sensing and GIS analysis. During these field investigations conducted with the help of community members and local government technical officials, various land use activities carried out by communities in the watershed were identified and analyzed for their implications on the river ecosystem health. In course of the surveys, the status of riverbanks

*Implications of Land Use and Cover Changes on Upper River Rwizi Macro-Watershed Health… DOI: http://dx.doi.org/10.5772/intechopen.99611*

and buffer zone degradation as well as highly degraded zones within the watershed were ascertained.

### **3. Results**

### **3.1 Land use and cover changes between 1990 and 2021**

Land use and cover characteristics in the upper Rwizi macro-watershed exhibits both highly spatial and temporal variations. The detected spatial and quantitative changes in land use and land cover between 1990 and 2021 are given in **Figures 3**–**7**.

### **Figure 3.**

**Figure 5.** *Land use and cover distribution for Mbarara sub-watershed between 2016 and 2021.*

**Figure 6.**

*Land use and cover changes for Mbarara sub-watershed between 2016 and 2021.*

### **Figure 7.** *Land use and land cover distribution between 2003 and 2021 based on Google earth images for a section in Mbarara City.*

### *Implications of Land Use and Cover Changes on Upper River Rwizi Macro-Watershed Health… DOI: http://dx.doi.org/10.5772/intechopen.99611*

There are five land uses and covers detected as shown in the figures. From **Figures 3** and **4**, it is vividly noticeable that whereas, a decrease in forestland and grasslands is noticeable from 1990, farmland and settlements have expanded drastically.

**Figure 4** illustrates the percentage land use and cover distribution in the study area from 1990 to 2020. By 1990, grassland as the dominant land use and cover type spanned 45% of the total study area coverage followed by farmland at 30%. Forest land, open water and settlements covered 12%, 10% and 3% respectively (**Figure 4**). Whereas grassland and forest cover have diminished drastically by 64% and 71% respectively between 1990 and 2020, settlements and farmland have increased tremendously by 79% and 50% respectively over the same period (Appendix 2).

The study area has experienced a drastic conversion of forests and grasslands to settlements and farmlands. For example during the 30 year study period, over 419 km2 of grasslands and 126km2 of forest land have been converted to settlements and farmlands (Appendix 2). The reclaimed open water sections along the river valley have been converted to settlements and farmlands covering 63.8 km2 between 1990 and 2020.

Analysis of land use and cover changes within Mbarara sub-watershed between 2016 and 2021 shows drastic changes in their distribution (**Figures 5** and **6**). During the five year period, forests, open water and grassland reduced by 51%, 54% and 26% respectively within Mbarara sub-watershed. Meanwhile, farmland and settlements increased by 25% and 17% respectively during the same period (Appendix 3). By 2021, farmlands and setllements were the dominant land use and cover types in Mbarara sub-watershed covering 56% and 16% respectively. On the other hand, forests and open water were the least land use and cover types within Mbarara subwatershed occupying 7% and 3% respectively (**Figure 6** and Appendix 3).

Within the Mbarara sub-watershed, 33km2 of forest land and 28km2 of grasslands were converted into settlements and farmlands between 2016 and 2021 (Appendix 3).

The study area has experienced a drastic conversion from natural land covers especially grasslands and forests to human dominated covers including farmlands and settlements over the past 30 years and more (see Google earth images in **Figure 7**).

### **3.2 Prevailing human activities in the study area**

The main human activities in the watershed include crop farming, livestock rearing, fish farming, brick making, sand mining, motor vehicle washing and growing of eucalyptus trees. Forests have been cleared to open up land for farming and settlements. Following field investigations along the Rwizi river valley, it was established that there is increased farming and settlement activities in the study area (**Figure 8**). Reports from the local communities revealed that due to the falling crop yields, many farmers have started encroaching on wetlands along the river valley and forested areas in the search for fertile soils.

The observed farming practices in the study area include both arable and livestock farming. Whereas arable farming is dominant in lowlands and middle slope elements, livestock is commonly practised in the upper slope sections. The major crops grown include both perennial and annuals. The perennial crops include bananas (*Musa paradisiaca*), coffee (*Coffea spp*), tea (*E. abyssinica*), sugarcane (*S. officinarum*) and mangoes (*M. indica*) grown for commercial purposes. The annual crops include Irish potatoes (*Solamum tuberosum*), sweet potatoes (*I. batatas*), maize (*Z. mays*), beans (*P. vulgaris*), peas (*P. sativum*), finger millet (*Eleusin coracana*) and vegetables. In most cases, the crops are inter-cropped. For example farmers inter-crop annual crops in banana gardens especially during the wet season. The dominant cropping systems in the watershed is banana/coffee system.

**Figure 8.** *Farming activities along Rwizi river buffer zone. Photo credit, Ayesiga, March, 2021.*

The study area has experienced increased population growth with a population density of 361/km2 [23]. The high population growth in the upper river Rwizi macro watershed has led to establishment of several settlements of both rural and urban setting (**Figure 9**). In the study area, settlements are dominant in the valley bottoms and lower slope elements (**Figure 9**). This has led to establishment of roads, buildings and installation of various utilities such as power transmission and telecommunication lines (**Figure 9**).

Due to rapid urban development in the region, there has been an increase in demand for construction materials including sand and bricks. In order to meet the demand for construction materials, local communities have embarked on sand mining (**Figure 10**) and brick making (**Figure 11**) along the riverbanks, wetlands and buffer zones.

### **3.3 Implication of changing LULC**

Changes in the land use and cover characteristics associated with increasing human activities have adversely affected the watershed properties. As already noted, there has been unprecedented conversion of natural land covers into human induced types. Following field investigations, it was established that many slopes flanking the river valley appear to be intensively cultivated leading to the emergence of many bare surfaces (**Figure 12**). Increased farming activities have affected

**Figure 9.** *Urban settlements along Rwizi river valley and buffer zone. Photo credit, Ayesiga patience. August 2020.* *Implications of Land Use and Cover Changes on Upper River Rwizi Macro-Watershed Health… DOI: http://dx.doi.org/10.5772/intechopen.99611*

### **Figure 10.**

*Sand mining close to river Rwizi near Mbarara City and Rwizi's buffer zone in Nyakayojo. Photo credit, Nseka, December 2020.*

### **Figure 11.**

*Brick making site near Ruti in Mbarara City and Nyaihanga in Rwampara Distrct. Photo credit, Ayesiga, February 2021.*

hillslope hydrological properties. This has resulted into increased runoff due to reduced infiltration as evidenced by many gullies and other erosion features on the landscape (**Figure 12**).

The study established that many urban centres have emerged in the study area over the past 30 years. Settlements dominated by urban sprouting have attracted the development of socio-economic infrastructure (**Figure 13**). The construction of socio-economic infrastructure has created paved surfaces that inhibit infiltration thereby increasing surface runoff, erosion and flooding of the lowlands within the watershed.

Due to increasing urbanization, illegal land acquisitions along the river's buffer zone have occurred in the watershed. Several houses as well as crop gardens have illegally been established along the buffer zone within the upper river Rwizi macro watershed. An interaction with communities revealed that illegal land acquisitions along river Rwizi buffer zone has resulted in the reduction of its width and depth (**Figure 13**). Following field investigation and interaction with local communities, it was established that community members no longer need bridges to cross river Rwizi along several of its sections (**Figure 14**). The act of walking in this river is an indicator of low flow velocity and reduced water quantity.

During field surveys, it was established that the river channel is a few metres away from the gardens, however, due to encroachment on the river's banks, it was

**Figure 12.** *Intensively cultivated slopes which appear to be degraded. Photo credit: Nseka, July 2020.*

**Figure 13.**

*Socio-economic infrastructure sprouting along the Rwizi river valley. Photo credit, Nseka Denis, September 2020.*

hard to realize that there was water flowing. Following an interaction with communities, it was indicated that what used to be papyrus-filled riverbanks has now been cleared and instead, there are water channels from the river flowing to people's gardens. Farmers revealed that they have no alternative to farming other than Rwizi riverbanks, buffer zones and wetlands. Communities living within the upper Rwizi macro watershed confirmed that the water levels in the river system has declined over the years. They, therefore, live in fear that the river will be no more in the

*Implications of Land Use and Cover Changes on Upper River Rwizi Macro-Watershed Health… DOI: http://dx.doi.org/10.5772/intechopen.99611*

**Figure 14.**

*Shallow section of the river channel where local communities cross without bridges. Photo credit, Ayesiga, September 2020.*

coming years if nothing is done to save it. During interactions with local communities, it was further reported that "the formerly wider river is narrowing". Sometimes, during the dry season, since there is hardly any water flowing from the hills, the water levels reduce into a small stream and, if one is not keen enough, they would think it is not a major river. Local communities indicated that sand mining and brick making along the riverbanks and its buffer zone have almost changed its course. Farming and sand mining are among the most destructive activities chocking river Rwizi to extinction. Due to increased human activities along the river valley, compounded with wetland and swamp destruction, the water levels in the river channel and its tributaries have drastically reduced. This is vividly evidenced by the river's water flow gauging station that is no longer used to monitor flow dynamics (**Figure 15**).

Following field investigations as well as interaction with local communities and key informants, it was established that the water levels of river Rwizi has dwindled by two and a half meters from the highest level where it used to be as indicated by the original gauging pillars at Nyamitanga which were established in 1970

### **Figure 15.**

*The river's water flow gauging station near Nyamitanga in Mbarara town has been rendered useless. Photo credit, Ayesiga patience, October 2020.*

(**Figure 15**). Communities living in the watershed revealed that memories of the river with its ample clean water, thick vegetation, wild animals and birds are quickly fading. A close observation of the river channel indicates higher levels of turbidity, with the channel water turning to brown (**Figures 14**–**16**).

High levels of deposition were also evident in the form of pebbles, silt and clay on the riverbed that has been exposed following low water levels and subsequent reduction in water flow velocity as observed below Rubaya bridge along Buremba road and Ngaromwenda bridge on the Mbarara-Kabale highway (**Figure 16**). The drop in water levels is turning away investors whose project's lifeline depends on good volume of water in the Rwizi river. The drop in water levels is most likely, linked to the degraded hillslopes that no longer have the capacity to recharge the river system.

Due to continuous watershed degradation, many sections of the river channel have been invaded by the waterweed (**Figure 17**). The invasive water hyacinth has congested the river, right from Ndeija sub-county in Rwampara District up to Sango bay in Rakai and the problem has been exacerbated by destructive agricultural practices within the watershed.

The water hyacinth is an indicator of polluted water with many nutrients from the surrounding gardens. Following an interaction with communities, it was revealed that the river's deterioration is due to widespread illegal land grabbing along the fragile riverbanks and buffer zone.

### **Figure 16.**

*Dropped water levels along sections of the river Rwizi. Photo credit, Ayesiga patience, December, 2020.*

**Figure 17.** *Sections of the river invaded and covered by water hyacinth near Mbarara City. Photo credit, Nseka, December 2020.*

*Implications of Land Use and Cover Changes on Upper River Rwizi Macro-Watershed Health… DOI: http://dx.doi.org/10.5772/intechopen.99611*

### **4. Discussion**

### **4.1 Land use and cover changes**

The original land cover status for the upper Rwizi macro watershed was generally a natural habitat of diverse flora and fauna experiencing natural hydrogeomorphological processes [21]. The hillslopes were intact, concentrated and promoting the natural movement of water and sediment [15]. The hillslopes flanking the watershed were once well covered by dense vegetation dominated by *Themeda Triandra* and *H. rufa* grass species [21] as well as tree species including *Vernonia ammygdalina*, *Acacia sieberriana*, *Acacia hockii, C. edulis* and *Albizia coriaria* [20] such that surface runoff was limited [17]. The study findings reveal a significant change in the land use and land cover distribution within the upper Rwizi river macro-watershed during the study period. In the study area, it is obvious that trends of land use and cover changes can be observed in the different periods due to evolvement of urban development and farming. Perhaps the most remarkable changes seen in this analysis were in form of settlements and farmlands, which have increased rapidly in the macro watershed. Settlements and farmlands have replaced the pre-existing natural forests, grasslands and open waters. They have directly changed the overall landscape composition of the watershed (**Figures 3**–**7** and Appendix 2 and 3). The study findings vividly show that there has been a drastic conversion of natural land cover to human manipulated types. It was observed that most of the watershed has undergone massive transformation over the last three decades. These rapid changes could be attributed to the rapid population growth in the watershed over the past few decades [23]. The high population in the region of over 2,574,000 persons [31] and density of 361/ Km2 [16] has put tremendous pressure on the land cover, leading to resource overuse and subsequent degradation [17]. This phenomena has also been responsible for the development of urban settlements (**Figures 9** and **13**). As observed by [6], population and economic growth often lead to spatial expansion of cities. This expansion may occur at the expense of increased risk of flooding, soil loss, riverbank erosion, changes in river courses, sediment load deposition and water pollution [1]. These environmental problems are aggravated by land use change from forestry to agricultural and other development activities such as construction of infrastructural facilities [4]. There has been a significant increase in building density accompanied by large-scale construction of socio-economic infrastructure including roads in the study area [32]. This has resulted into acute shortage of farmlands forcing people to encroach on the sensitive riverbanks and buffer zone [15].

Demographic pressure and the decreasing cultivatable land has significantly contributed to encroachments on both wetlands and the river's buffer zone. Increased demand for farmland and settlement land in the study area has led to uncontrolled clearance of forests and grasslands (**Figures 3**–**7**). The study findings are in keeping with observations made by [19] who noted that most of the natural land cover in the Rwizi catchment have been destroyed due to increasing land use practices. As can be observed on most of the hillslopes in the watershed, there has been complete depletion of vegetation cover (**Figure 12**). Many hillslopes in the watershed are already bare due to degradation. During the field investigations, it was observed that every available space has been intensively cultivated. Gardens appear like a continuous carpet for kilometers from the valley bottoms to uppermost slope sections (**Figure 12**). The river system has, therefore, been modified to meet the needs of human development in different social development stages. Many people have illegally acquired land along Rwizi riverbanks and buffer zones consequently destroying its wetlands. A number of higher order streams have been invaded, cut off and even

buried, forcing most of them to transform into narrower streams. Most wetlands, which work as granaries for water and economically release it during the dry periods, have been destroyed to pave way for settlements and farming activities. As observed by [33], this scenario has partly been due to the existence of informal land acquisition policies and the growing land modification in the region.

### **4.2 Implications of land use and cover changes**

The upper river Rwizi macro watershed was under a natural hydrological balance until about 100 years ago, when the dense forests, shrubs, thickets and tall grass began to be depleted [24]. As indicated by [34], the reduction in forest cover greatly affects the landscape's ability to intercept rainfall which greatly affects hillslope hydrological characteristics. Land use and cover changes affect various hillslope hydrological processes including interception, infiltration and evaporation, thereby influencing runoff generation [35]. It has been reported elsewhere that land use and cover changes often lead to natural ecosystem deterioration and landscape degradation [33, 36]. The highlands of the upper river Rwizi macro watershed have been severely degraded as evidenced by bare surfaces in many sections (**Figures 7** and **12**). This has affected rainfall partitioning thus exposing the hillslopes to severe runoff processes [15]. Vegetation cover degradation which is one of the most important parameters in water and soil conservation [36] has resulted into increased runoff coefficients and soil erosion in the upper Rwizi macro watershed [15].

In Ref. [5] reported a change in the occurrence of the highest runoff and erosion processes incidences in the highlands of South Western Uganda (location of study area) during the year. During the 1960s and earlier when the status of vegetation cover on the valley side slopes was still modest to abundant, the main runoff and erosion risk used to be during the period of March/April [15]. The pattern has, however, changed due to encroachment and the decimation of vegetation cover on valley side and upper slopes in the highlands [19]. The period of worst erosion problem has changed to September/October. This is due to heavy runoff from intense storms that are experienced after the aggressive dry season (June to August) that rage down the almost bare slopes [24]. The change in the main runoff and erosion risk is due to bush burning which is dominant during the prolonged dry season. Bush burning is practiced to provide fresh and greener pastures for the animals and prepare the land for cultivation [21]. Bush burning exposes the land surface to severe runoff and erosion during the subsequent September to November (SON) wet season in the region [17]. This explains why runoff and erosion processes are very intensive at the onset of the SON rainy season. Runoff and erosion processes, however, reduce as the rainfall season proceeds. This is associated with new vegetation that emerges due to increased moisture [15]. The emerging vegetation encourages infiltration while reducing runoff processes [37].

The change in land use and land cover has had significant negative impacts on the soil and river's water quality within the watershed. This is due to the application of excessive amounts of chemical fertilizers and pesticides, which inevitably runoff into the river system. It was reported during community interactions that whenever it rains, water runs on bare slopes, carrying topsoil, pollutants and silt with it. Heavy metals, fertilizers and herbicide have contaminated the waters, thus damaging ecosystems dependent on Rwizi river waters [24]. The silt is affecting the quality of the water in the river system [17]. The expansion of settlements threaten the river ecosystem health, particularly increased sewage disposal and solid waste dumping in rivers. People have built in the river's catchment, thus interfering with the water flow. Increasing urbanization taking place is affecting the hydrological characteristics of a watershed by reducing infiltration of rainwater into the ground

*Implications of Land Use and Cover Changes on Upper River Rwizi Macro-Watershed Health… DOI: http://dx.doi.org/10.5772/intechopen.99611*

and increasing the volume and speed of surface runoff. The replacement of forest cover with paved surfaces or other land use types increases water yield due to reduction in water losses resulting from soil compaction [38]. This increases stream discharge, which is an important element in fluvial processes of erosion and sediment transportation [2]. The processes of erosion and sediment transport result from an interrelated set of natural, human and hydrologic factors within a watershed [10]. The increasing artificial surfaces could be the potential source of pollution within the watershed. Several studies have also shown significant impacts of land use and land cover changes as a contributing source for water pollution [3, 5, 9]. Conversion of the existing land cover increases exposure to other problems in a watershed [7]. This is further confirmed by [11] who maintains that clearance of forest cover accelerates geomorphic processes leading to high sediment yield, rapid channel degradation and mass wasting. In Ref. [13], confirms that destruction of wetlands that can hold water and allow it to flow naturally leads to fast-flowing water in the river system. Due to encroachment within the river Rwizi watershed, the wetland and forest cover along the river valley can no longer hold water and release it in the dry periods. The study established that rainwater flows out of the river system very fast. This situation could contribute to other possible environmental problems such as microclimate change, increased run-off, pollution and degradation of ecological values as well as services within the watershed. Such scenarios could translate into increased hardships for local residents that manifest through decreasing access to clean water, flooding, erosion and intensified salination.

### **5. Conclusion**

The upper river Rwizi macro watershed has experienced a drastic decimation of natural land cover categories especially forests and grasslands to human manipulated types dominated by settlements and farming due to increased population amidst informal land acquisition practices. The dominant human activities in the watershed include crop farming, livestock rearing, fish farming, construction, brick making and sand mining. Changes in the land use and cover characteristics associated with increasing human activities have adversely affected the upper Rwizi macro watershed properties. The watershed ecosystem health is worrying due land cover degradation. Due to increased human activities along the river valley compounded with wetland and swamp destruction, the water levels in the river channel and its tributaries have drastically reduced. The drop in the water levels is also due to the hillslopes inability to recharge the river system. The hillslope hydrological characteristics in the watershed are severely hampered. It is, therefore, recommended that afforestation be undertaken in the degraded areas of the watershed. The responsible agencies should also put more efforts into proper implementation and monitoring of already established laws and regulations like the National Environment Regulations, 2000 for wetlands, riverbanks and lake shores management. This will help to restore vegetation cover which could improve on hillslope hydrological balance. Restoration of the vegetation cover will counteract runoff and erosion processes which are on the increase. There is also an urgent need to provide alternative livelihood to river dependent communities in the watershed. With Mbarara's transformation into a city, there is need to reduce the scale of illegal settlements and development activities encroaching into the adjacent river valley wetlands. This study, therefore, recommends a change in land acquisition policies particularly in wetland and forested areas by revising the overlapping mandates of national agencies and district land boards that issue land titles in these fragile

sensitive ecosystems. This should be coupled with a strict adherence of watershed developers to Environmental Impact Assessment standards.

### **Acknowledgements**

The authors gratefully acknowledge the research grant from the Government of the Republic of Uganda (2020/2021) through Makerere University Research and Innovation fund which funded data collection activities and analysis. The authors also gratefully thank the community members within the upper Rwizi macro watershed and the local government technical personnel who provided data and participated in the field surveys and discussions.

### **Conflict of interest**

No conflict of interest by the authors.

### **List of appendices**

### **Appendix 1: Land use and cover description**

### **Appendix 2: Land Cover changes based on Landsat imagery (1990–2020)**

*Implications of Land Use and Cover Changes on Upper River Rwizi Macro-Watershed Health… DOI: http://dx.doi.org/10.5772/intechopen.99611*

### **Appendix 3: Land cover changes based on Sentinel imagery data (2016 to 2021)**

### **Author details**

Denis Nseka1 \*, Hosea Opedes1 , Frank Mugagga1 , Patience Ayesiga2 , Henry Semakula1 , Hannington Wasswa1 and Daniel Ologe1

1 Department of Geography, Geo-Informatics and Climatic Sciences, School of Forestry, Environmental and Geographical Sciences, Makerere University, Kampala, Uganda

2 Department of Geography, Faculty of Education, Bishop Stuart University, Mbarara, Uganda

\*Address all correspondence to<EMAIL_ADDRESS>
© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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### **Chapter 4**