Climate Change, Regional Water Balance and Land Use Policy, in the Watershed of Lake Kinneret (Israel)

Long term data record (1944-2018) of climatological conditions in the Lake Kinneret and its watershed ecosystems was statistically evaluated and the impact of Anthropogenic operations was included as well. Precipitation input source is obviously uncontrolled natural component whilst the other three regional water outflows pathways are under anthropogenic control: Evapo-transpiration (ET), Runoff and underground flows. Indications for climate change expressed as air warming with consequences on regional (watershed and the lake) water resources and consumption capacities policy in the drainage basin and in the Lake are discussed. The decline of air temperature from 1940 to 1970s is probably due to a change in the Albedo effect. After the decline air temperature was twisted towards elevation. Climate change caused a decline in rainfall, followed by a reduction of Jordan and other river discharges and underground flows, accompanied by a decline of WL. With respect to climate change, water allocation for agricultural consumption was shrunk.

From the bottom of the mountain foothill up to 1400 masl dominancy of Oak (Quercus spp) spars forest; between 1400 -1800 masl spars cover by Oak trees and bushes strongly impacted by anthropogenic destruction; above 1800 masl kind of Alpine vegetation of low sub-bush plants.
Schumacher [5] documented geographical observations in the Jaulan (Golan) region. He explored the Golan region on behalf of "The German Society for the exploration of the Holy Land" during 1883-1885. In the report that was published "Across the Jordan" in 1888, he confirmed that shortly earlier, "Stony Jaulan (Golan) has been covered with thick growth of forest trees; the still extensive oak (Quercus) woods…and the beautiful oak trees which singly and in groups…in the north of the Batihah (Beteicha, Bethsaida Valley) and Pitavia (Pistacia) in the vicinity of the oaks…" Schumacher (1888) also indicated the absence of wood growth (Forest) in the southern high plateau, which has probably been under deforestation. In his textbook of Geo-botany, Zohary [6] also has indicated that the Association of plant type of Forest is no more distributed in Israel except for several group residues of Pines in the upper Galilee whilst the Kinneret watershed was not mentioned. The Pine deforestation was mostly due to agricultural soil suitability of Randzine, which is preferred by Pine trees. [6] also mentioned the residue of groups of trees in the Kinneret watershed on the High altitude of the western mountains of the Upper Galilee. The low densities of low trees as Pistacia and Ziziphus in the southwestern "Lower Galilee" were also indicated by Zohary [6]. An area of 66.2 km 2 located northeast of Lake Kinneret is presently a Nature Reserve, namely, Yahudia Forest [7] [8].

Material and Methods
This study represents an insight into the water balance of the Lake Kinneret watershed, the impact of consumption on the lake and the hydrological consequences

Water Consumption
The available information presented in this paper is due to the Israeli part of the Kinneret Watershed which comprises about 73% (2000 km 2 ) of the total (2730 km 2 ). The Information that was submitted by regional and national water authorities indicates the following: Until the late 1990s, the total legislated water allocation to this part of the Kinneret watershed ranged between 100 and 120 mcm (10 6 m 3 ) per year for agriculture and domestic consumption ( Table 2).
Later on, a further downward restriction to 85 mcm/y was implemented. As a result of a long-term drought (2014-2018), restriction was lowered to a level of 68 mcm/y with additional supply from Lake Kinneret to the Golan Heights of 19 mcm/y. Irrespective to this solid documented information representing decline of water consumption [2] and Table 2

Land-Use Policy within the Watershed Area
For the outline of regional Evapo-transpiration water loss, a GSI map of Land Use as of 2004 was charted. The information covers Israeli territorial land (2000 km 2 ; 73%) within the total Kinneret watershed (2730 km 2 ). The results are given in Table 1 and Figure 1. Table 2 indicate a significant deficit (3821 minus 2034 = 1787 mcm/y) of rainfall water supply to cover the maximal potential Evapo-transpiration demand.

Results in
A brief summary of an International Conference about Land-Use Land-Cover has been recently published. It is a topic that is under a wide scientific research [9]: "Forestation, fallow management and agricultural and pasture management are known as reducer of greenhouse gas emission" [10].
It is a moderately accepted policy of land use by no incentive to destroy natural (Virgin) forest or to convert them into biomass plantations with low value of nature conservation and biodiversity protection.
Since the 1950's the region of Amazonia in South America has been associated  with a huge increase in the extent and rate of deforestation area cover, approximately 500,000 km 2 . Current rates of annual deforestation range between 15,000 and 20,000 km 2 , causing changes in water budgets as well as a decrease in rainfall following the replacement of forests by pasture. It was widely documented [11] [12] [13] [14] [15]. Several surface characteristics such as albedo, rainfall, and interception loss dynamics were quantified for the surface cover of forest, bushes, grass (pasture) or uncultivated land. Forest cover surface shows no distinct seasonal trend of evaporation, whilst other types of cover or uncovered soil surface do. Moreover, during the dry season, pasture exhibits moisture stress due to their shallow root penetration whilst forest may suck water from deep layers of soil moisture [15].
There is a coupling between soil surface and the climate as mediated by water cycles [9]. The intensity of such dependence might be varied in relation to type and cover density of vegetation.

Regional Water Balance: Evapo-Transpiration (ET) Water Loss and Consumption
The information given in Table 3 called for an obvious question: How does agricultural management "absorb" such constraints of drought and legislated water supply restriction? The answer is partly given in an Interim Report [16]: tions. Undoubtedly, the most important and significant variable of regional water balance is rainfall. If the climate is changed, and therefore, water consumption and possibly land use policy reduces, it will have a significant impact on the end product of the drainage-lake water level. The second level of importance is due to Evapo-transpiration (ET). This variable of the regional water balance is strongly affected by climate conditions, land plant cover, water availability and soil features. Soil moisture reduction, which is strongly affected by land use policy and, therefore, climate change, might also reduce evaporation rate. Nevertheless, land use-land cover policy is controlled by human activity (anthropogenic). The degree of creditability given to the final conclusion is de- The most important impact on ET is given by the air temperature and, therefore, the runoff is the result of the difference between rainfall and ET [20]. Moreover, climate change may cause changes in rainfall frequency and intensity, which might have a significant impact on IL's quantity. Documentation of climate change expression as a combination of rainfall and wetter winters and drier summers caused by evaporation is provided by [21]. Reynard et al. [21] also indicated that rainfall intensity and distribution mainly determined the hydrological response of a watershed. [9] concluded that natural watershed ecosystems are mostly well balanced. Nevertheless, minor effects are to be expected on water balance caused by ET alteration caused by land-use changes. It is suggested that recently modified climate conditions, i.e. rainfall decline, combined with a long history of deforestation and shorter implementation of vegetation-covered land-use policy, promoted water input decline in Lake Kinneret and resulted in WL lowering. Table 4 indicate a reduction of Water-Swampy-Flooded area from 100% occupation to less than 5% cover.

Results in
Comparative land-use management between two years of 2004 and 2019 is shown in Table 5. Surface area that is water cover indicates as 171 km 2 , while in Table 5 it is only 8.1 because the surface area of Lake Kinneret (168 km 2 ) was eliminated as not being anthropogenic land-use. Table 5 indicate a reduction of agricultural land-use in the Kinneret Watershed whereas crops and financial benefit per areal unit were improved simultaneously with a reduction of water consumption (from 110 mcm/y to 68 mcm/y). Reduction of water consumption when the benefit was enhanced is the   watershed was efficiently managed to follow national demands for drinking water supply from Lake Kinneret as affected by climate change. It was attached to the administrative adaptation to actual conditions through achievement controlled by three crucial parameters: 1) climate conditions (rainfall intensity); 2) demands for reasonable agricultural revenue; and 3) national demands for water supply. Water-saving in the drainage basin was included among emergent achievements aimed at slowing down the rate of Kinneret WL decline during an  Table 1 and Figure 1.

Results in
The following are the annual values of different Land-Use-Land-Cover and ET type capacities, which are acceptable worldwide: regional ET capacities during 2004 were evaluated; results are shown in Table 6. Table 6 indicates that water consumption in the Israeli part of the Kinneret Watershed is divided as follows: 27% or 17% (Total-555; Lake Kinneret excluded-347 from 2034) of rainfall water resource is Evapo-transpiration and 70% is the total of runoff and underground. With respective consideration to the seasonal Landsat images ET annual water consumption during 2004 was maximum 555 and minimum 347 mcm.

Data in
A significant exceptional factor is not considered in Table 6: seasonality of agricultural crop corrections is shown in bold.
For the evaluation of seasonal water consumption, two Landsat images were charted and aerial land use was computed during October 2018 (summer-fall season) and February 2019 (winter-spring season). Results are shown in Table 7 and Figure 6. Table 7 indicates that cultivated grass-covered area (no trees) (wheat or corn) should be considered as water ET consumers during half a year only. ET water utilization in uncultivated area is validated also during 6 winter months only. Information given by Kaplan [7] (and unpublished) [8] indicates that forest/groove deciduous vegetation of 518X 10 3 plants covering an area of 66.2 km 2 , located in the southeastern region of the Kinneret Basin (Yahudiye Forest Park), consumes annually ET waters throughout full-year cycle ranged between 14.5 and 18.5 10 6 m 3 . It is considered when the annual total ET capacity of an Oak tree is 0.279 mm and one Oak tree canopy cover is 100 m 2 .

Rain and River Discharges
Brief History (1970-2018) of Wl Fluctuations in Lake Kinneret ( Figure 2) A daily monitor of WL measurement record of Lake Kinneret has been available since 1926. The close relation between Kinneret WL and precipitation and discharge regimes in the watershed is presented in Figure 3 and Figure 9. Historical (9000 years before present) data of the Kinneret WL is summarized in Figure 5. Two different methods: 1) distribution of algal fragments in sediment cores dated layers, and 2) granulometric analysis of dated geological layers [24] [25] documented that during the last 9000 years Kinneret WL fluctuated within      Results shown in Figure 3 indicates decline of rainfall and Jordan River discharges during the last 40 years. Givati and Rozenfeld [26] and [27]  increase ET but are too small to explain the magnitude of observed discharge decreases" is misleading.

Air Temperature
A record of Maxima and Minima of air temperatures measured at the Meteorological Station Dafna located in the northern part of the Hula Valley are summarized in Figure 7 and Figure 8. Hourly measurements were averaged to daily and daily to monthly and monthly to annual means. These annual data were plotted as a Fractional Polynomial Regressions Vs Years (Figure 7, Figure 8).   Table 7). Geographically delineation of the Israeli Part of the Kinneret watershed is indicated. The annual maximum and minimum were elevated by 2.7˚C and 1.5˚C respectively.

Results in
Maximum RAD value reported for Lake Kinneret [28] during 1965-1975 for   Evert 2004) and periodical accumulated ET ranges (mm) are given in Table 10. Results in Table 10 represent accumulated impact in two periods and indicates similarity. Nevertheless, results given in Table 9 were regressed as Fractional Polynomial relations ( Figure 10) between RAD and years and a slight increase of 1.3 MJ/m 2 /day of radiation during 1995-2018 was indicated in the Hula Valley. Moreover, results given in Figure 11 indicate positive relation between RAD and AT whilst, as likely predicted, inverse relation between air temperature and Relative Humidity. When air temperature was elevated from 15˚C to 30˚C, radiation increased by 10 MJ which might effectively cause an ET enhancement. The monthly change of radiation ( Figure 12) prominently represents fluctuation range between <10 MJ/m 2 /day in winter and 27 MJ MJ/m 2 /day in mid-summer. Results in Table 10 show that the higher impact on ET is attributed to AT. We assume that the climate change in the Kinneret drainage basin as approved by prominent AT elevation and a slight RAD increase have an impact on water consumption through ET. Conclusively, the significant increase of Air temperature, slight elevation of RAD and the Rainfall reduction accompanied by river discharge reductions confirm climate change in northern Israel.
Winn et al. [2] are doubtful about climate change (global warming) impact on the water flows reduction into Lake Kinneret. Whilst, long term record of    and solar radiation enhancement are of inducement for this consumption process. Moreover, rainfall decline not only lowered river discharges and Kinneret water inputs, but also enhanced creation of preferential free space in the Hula Peatland underground as an incentive for water loss.
The management of agriculture requires water consumption in the Hula Valley is not only significant as an income resource. It is also ultimately required for the peat soil deterioration prevention and Kinneret water protection. Removal of the agriculture from the Hula Valley will enhance soil structure deterioration, dust storms, underground fire and rodent outbreaks, and water loss. Consequently, part of the Kinneret water balance is dedicated to agricultural management in the Kinneret drainage basin and the partitioning allocation between farming and the lake water level demands is regulated efficiently by the National Water Authority.

Chill Hours Record (1988-2019)
We incorporated Chill hours results of the "Local Chill Hours" Model data collected during 1988-2019 as a supportive information service to grove crop managers. The computation of Chill hours is based on a modification of the "Chill Days Model" [31] [32] and the "Utah Model" as follows: Air Temperature (˚C) is continuously monitored and hourly averaged; each hour with mean temperature below 7˚C is valued as 1; hourly temperature within average range of 7.0˚C -10.0˚C is valued as 0.5; mean range of 10.0˚C -18.0˚C is valued as 0 and higher than 18.0˚C as −1; each 24 hours are totally summarized into one number: if the total summary is a positive number which is indicating the additional Chill hours for those 24 hours. Daily record of Chill Hours reflects obviously air temperature changes. Daily Chill Hours report is practically carried out during winter season (October through April). Long-term (1988-2019) record of daily Chill-Hours indicates annual atmospheric thermal fluctuations, i.e. climate change. Lake Kinneret and its watershed are located in a subtropical region and therefore hydrological seasonality is cycled from October through September of next year (Figure 13, Figure 14). The annual fluctuations of monthly means of air temperature are shown in Figure 14. The maxima, minima and averages clearly indicate decline during winter and elevation later on. Figures 15-17 indicates the following: temporal (1988-2019) decline of the daily number of chill hours ( Figure 15); shortening length (in days) of the chill hours season ( Figure  16) and the longer time delay (in days) of the initiation of chill hours existence ( Figure 17). Conclusively, additional evidence of climate change occurrence which is represented as atmospheric air temperature elevation is given.      The other supportive parameters presented in this paper are: decline of rainfall, followed by a decline of Jordan and other rivers discharges and a consequent decline of Lake Kinneret WL. Climate change caused rainfall decline followed by a reduction of runoffs and consequently a decline of WL. Climate change towards dryness enhancement expressed as SPI, enhancement, precipitation decline, river discharges and lake input volumes decrease accompanied by lowered WL and water availability for supply and elongation of RT duration, increase of lake water salinity. Epilimnetic nitrogen deficiency and phosphorus sufficiency en- tively (the 2020 information includes documentation through March and later is predictable). The administrative consequence to droughts was a reduction of water allocation for agricultural irrigation, which resulted in a decline in the ET capacities.