This study aims to estimating annual soil erosion rate and its spatial distribution in the Bou Namoussa water-shed located in the North-East of Algeria by applying the revised universal soil loss equation (RUSLE) within a Geographical Information System environment (GIS). The application of the RUSLE model in different natural environments and on every scale takes into account five key factors namely: the rainfall erosivity, the soil erodi-bility, the steepness and length of slopes, the vegetation cover and the conservation support practices. Each of these factors was generated in GIS as a raster layer, their combination, resulted in the development of a soil loss map indicating an average erosion rate of 7.8 tꞏha–1ꞏy–1. The obtained soil loss map was classified into four ero-sion severity classes; low, moderate, high and very high severity representing respectively 40, 30.48, 22.59 and 6.89% of the total surface. The areas, showing moderate, high and very high erosion rates which represent more than half of the basin area were found generally located in regions having high erodibility soils, steep slopes and low vegetation cover. These areas should be considered as priorities in future erosion control programs in order to decrease the siltation rate in the Cheffia reservoir.
Setif city covers an area of 6550 km2; it is located about 300 km southeast of Algiers and 100 km to the south of the Mediterranean sea. The aim of our study is to know the tectonic mechanisms responsible for the emergencies and to highlight their chemical characteristics of water springs in Setif. Wherein thermalism is characterized by the presence of a number of thermal springs, the latest are usually related to recent large fractures deeply affecting the sedimentary formations and sometimes even crystallin basement. These fractures are often injected by Triassic evaporates; their directions are NNW–SSE, NW–SE, and NE–SW and limiting great structural units. Four groundwater facies were identified: the high percentage of sources, staking major accidents related to limestone mountains or to the basement, shows a calcium or sodium sulfate facies; and the sources are often hot (meso or hyperthermal). A second group, related to terrigenous saliferous formations, shows a sodium bicarbonate or sodium chloride facies. The geothermic interpretation allows us to conclude that the reservoir supplies the two aquifer systems of the thermal complex, and is stored in fissured Jurassic limestone, where water storage and circulation is beyond 2600 m deep.
The Tinibaouine region, located in north-eastern Algeria on the borders of the Batna-Belezma Mountains, is characterized by a semi-arid to arid climate with an average annual rainfall not exceeding 465 mm and an average annual temperature of around 22 ° C. This region is characterized by the cultivation of apricots as essential crop followed by that of olives, whose plots are all irrigated with the Tinibaouine spring water. These are 450 Ha of trees for apricot and 108 Hectare for olives which constitute the principal revenue of the citizens of this small village. This paper estimated the crop reference and actual evapotranspiration (ETO) respectively and the irrigation water requirement of apricot trees and olive trees. The long recorded climatic data, crop and soil data, effective water allocation and planning, the information about crop water requirements, irrigation withdrawals were computed with the Cropwat model which is based on the United Nations’ Food and Agriculture Organization (FAO), the Penman-Monteith method was used to estimate ETo. Crop coefficients (Kc) from the phenomenological stages of apricot and olive were applied to adjust and estimate the actual evapotranspiration ETc through a water balance of the irrigation water requirements (IR). The results showed that the annual reference evapotranspiration (ETO) was estimated at 3.71mm / day. The irrigation requirements were estimated at 35800 m3/ hectare for apricot, 6980 m3/ hectare for olive, also Irrigation needs estimated on land at 14185, 05 m3/ hectare for olive and apricot
