Abstract: The climate change is a main parameter which affects the element of hydrological cycle especially runoff. Then, the purpose of this study is to determine the impact of the climate change on surface runoff using land use map on 2008 and daily weather data during January 1, 1979 to September 30, 2010 for SWAT model. SWAT continuously simulate time model and operates on a daily time step at basin scale. The results present that the effect of temperature change cannot be clearly presented on the change of runoff while the rainfall, relative humidity and evaporation are the parameters for the considering of runoff change. If there are the increasing of rainfall and relative humidity, there is also the increasing of runoff. On the other hand, if there is the increasing of evaporation, there is the decreasing of runoff.
Abstract: The risk of water erosion is one of the main
environmental concerns in the southern Mediterranean regions. Thus,
quantification of soil loss is an important issue for soil and water
conservation managers. The objective of this paper is to examine the
applicability of the Soil and Water Assessment Tool (SWAT) model
in The Sarrath river catchment, North of Tunisia, and to identify the
most vulnerable areas in order to help manager implement an
effective management program. The spatial analysis of the results
shows that 7 % of the catchment experiences very high erosion risk,
in need for suitable conservation measures to be adopted on a priority
basis. The spatial distribution of erosion risk classes estimated 3%
high, 5,4% tolerable, and 84,6% low. Among the 27 delineated subcatchments
only 4 sub-catchments are found to be under high and
very high soil loss group, two sub-catchments fell under moderate
soil loss group, whereas other sub-catchments are under low soil loss
group.