Nigeria Sudan savannah is similar but with shorter grasses and shorter trees. Sahel savannah consists of patches of grass and sand, found in the northeast. In the Sahel region, rain is less than per year and the Sahara Desert is encroaching. In the dry northeast corner of the country lies Lake Chad, which Nigeria shares with Niger, Chad and Cameroon. Nigeria's Delta region, home of the large oil industry, experiences serious oil spills and other environmental problems, which has caused conflict. Waste management including sewage treatment, the linked processes of deforestation and soil degradation, and climate change or global warming are
Rail transport in Chad Imperial expansionist policy known as Mittelafrika. In the 1950s a line through Chad from Port Sudan to Nigeria was proposed but opposed by Chad governmental organisations. In 1958 plans for a line from Cameroon the "Société Civile d'Études du Chemin de Fer Douala-Tchad" (SEDOT) was formed, and continued planning led to start of construction in 1964 - the line was constructed as far as Ngaoundéré in Cameroon (the Trans-Cameroon Railway, completed 1975.). Initial plans were for an extension to Moundou in Chad, but this was not completed. In 1959 a multinational agency, the "Agence Transéquatoriale des Communications" (ATEC) was formed