CALCULATION OF SEDIMENT YIELD IN THE S1-1 WATERSHED, SHIRINDAREH WATERSHED, IRAN

Soil erosion and sediment redistribution are natural processes of paramount importance. They are causing environmental concerns such as land degradation, soil and habitat loss, water pollution, desertification, ecosystem alteration. They may also have severe consequences on human infrastructures, such as bridges, road and rail network; sedimentation and deposition on reservoirs. The integrated management of soil erosion at the catchment scale has always been of a great importance for agriculture and other fields such as ecology and water science. For this reason, the assessment of soil erosion and sediment transport is a key component of integrated catchment management. It is generally accepted fact that both sediment discharge series and soil erosion measurements are only available in a few and small to medium-size experimental catchments. The most useful tool available to catchment managers for soil erosion and sediment yield assessment is use of analytical models of these processes. In order to carry out this task, the IntErO model was tested in 48 catchments of Shirindareh watershed in Iran with different sediment data availability. One of the studied regions was S1-1 watershed where we studied soil erosion processes using this analytical and computer-graphic method. Calculated maximal outflow from the river basin was 41 m^3s-1 for the incidence of 100 years and the net soil loss was 3355 m³km-², specific 224 m³km-² per year. It was concluded that this model can be applied to this Region and may be applied to the other areas similar to Shirindareh watershed for simple, reliable identification of critical areas of soil erosion in watersheds. Nevertheless, further research is needed to address model limitations and to reduce model results uncertainty.