**2. Methods**

Climatological (precipitation, air temperature) data was supported by the Israeli Meteoroloical Service. Jordan River discharge and nutrient concentrations were supported by Kinneret Limnological Labortory Data Base and Mekorot Water Supply Company Jordan District. The nutrient concentrations and the phytoplankton composition structure in the epilimnion of Lake Kinneret during 1970–2018, as well as water level and ground water table (GWT) in the Hula Valley were all reevaluated and statistically analyzed. The information was given by Kinneret

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**Figure 1.**

*The Synergistic Impact of Climate Change and Anthropogenic Management on the Lake…*

Limnological Laboratory (IOLR), Mekorot-Water Supply Company-The Jordan Region Monitor Unit, The Israeli Hydrological Service, National Water Authority, and the Israeli Meteorological Service. The Statistical analyses used were fractional polynomial and linear regressions. The data on Agmon WL and the GWT depths were supplied by the Data Base Center of the Hula Project in the MIGAL-Scientific

The periodical occurrence of drought is given in **Table 1**. Results in **Table 1** indicate 62% periods (years) of three levels (A, B, and C) drought as SPI (specific precipitation index) values [1] during 1930–1980, and 42% during 1981–2014. Moreover, percentage of normal conditioned periods was higher during the latter period. Nevertheless, recent 5 years (2014–2018) were consecutive drought seasons. Data shown in **Figure 3** indicate precipitation decline since mid-1980s. The information that is evaluated in **Figure 1** was collected (from 1940) in the Dafna Station located in northern Hula Valley statistically indicating a decline of appox.

Periodical means of air temperatures measured in the meteorological Station in Dafna (Northern Hula Valley) during 62 years (1946–2008) resulted (°C) in the following changes: 20.2, 19.4, 18.9, and 19.8 in 1946–1958, 1959–1982, 1983–1990, and 1991–2008, respectively, indicating fluctuation ranges of −0.8, −0.5, and

**SPI level 1930–1980 1981–2014** A 34 21 B 26 18 C 2 3 D 38 58 *A—close to normal conditions; B—moderate drought; C—severe drought; and D—normal conditions.*

*Trend of changes (LOWESS; 0.8) of daily maxima (left panel) and minima (right panel) of air temperature*

*Drought level (A, B, C, and D) occurrence (%) evaluated as SPI values [1].*

*(°C) Dafna Station (Northern Hula Valley) during 1969–2001.*

*DOI: http://dx.doi.org/10.5772/intechopen.86512*

Research Institute.

**3.1 Climate change**

140 mm annually.

+0.9°C.

**Table 1.**

**3. Results**

*The Synergistic Impact of Climate Change and Anthropogenic Management on the Lake… DOI: http://dx.doi.org/10.5772/intechopen.86512*

Limnological Laboratory (IOLR), Mekorot-Water Supply Company-The Jordan Region Monitor Unit, The Israeli Hydrological Service, National Water Authority, and the Israeli Meteorological Service. The Statistical analyses used were fractional polynomial and linear regressions. The data on Agmon WL and the GWT depths were supplied by the Data Base Center of the Hula Project in the MIGAL-Scientific Research Institute.


*2.9. Gas Chromatography-Mass Spectrometry (GC-MS)*

The analysis of the volatile constituents in extracts was determined by GC-MS technique (Perkin Elmer Clarus, USA). Perkin Elmer Clarus 680 employed a fused silica column, packed with Elite-5MS and the compounds were separated using helium as a carrier gas at a constant flow of 1 mL/min. The injector temperature was kept at 260 ◦C. Oven temperature was set as follows: 60 ◦C (2 min); followed by 300 ◦C at the rate of 10 ◦C min−1. The spectrum thus obtained was compared with the database of the already known spectrum of components stored in GC-MS NIST library. The infrared spectrum of the extract was analyzed by FT-IR spectrophotometer in the range of 400–4000 cm−1.