كليدواژه :
فرسايش , رسوب , MPSIAC , GIS , +ETM
چكيده لاتين :
Undesirable effect of erosion may not be significant in short time, but it will be clear on long time. Erosion and soil losse. are the main concerns decrease soil fertility and yield production, deposition materials in waterways, irrigation channels and rivers, declining dam capacity, flooding and environmental pollution and closing roads. This research was performed using satellite data and GIS technique in Ziarrat watershed in Golestan province covered 98.7 km2 areas in order to estimate soil erosion and sediment yield. MPSIAC model evaluates erosion and sediment yield in hydrologic units by means of nine environmental factors derived geology, soil, run off, climate topography, surface cover, land use, surface and river erosion. For this purpose, the information layers dependent on model were made by GIS and finally sediment yield was determined 22043.79 ton/year using of spatial assessments and information layers overlapping. Soil erosion rate calculated by SDR (sediment delivery ratio) value, and erosion value was obtained 698.58 ton/year. Qualitative soil loss classification indicated that a large of watershed area was classified in to moderate erosion class based on MPSIAC model. Watershed sediment load was reported 18582.23 ton/year by hydrometric station, correlation of recorded results in hydrometric station with obtained results of model (Especially in inaccessible area) suggested that the findings of this model can be used in the study watershed for mangement especially in inaccessible contents.
