FAKTOR YANG BERPENGARUH TERHADAP TINGKAT KERAPATAN EROSI PARIT DI DAERAH ALIRAN SUNGAI KALIWUNGU (Factor influencing density level of gully erosion in Kaliwungu Watershed)

Distribution and density level of gullies reflect the level of land degradation on a catchment. This research aims to identify the distribution of gully and to calculate the density level of gully erosion in Kaliwungu Watershed. The distribution of gully was obtained through field survey, while the density level was analyzed based on landuse and landform maps. Gully distribution was overlayed on landuse and landform maps. Landuse was delineated by interpreting aerial photograph of Kaliwungu Watershed. Aerial imagery supported by the result of Sentinel image processing was used to observe vegetation density. Landform and slope were delineated from DEM. The gully small catchments were delineated by DEM and aerial photograph interpretation of Kaliwungu Watershed. Gully density is calculated by comparing erosion length and erosion volume to the small catchment extent. Descriptive analysis was used to determine the factors that influenced gully. The analysis was conducted based on the result of overlaying gully distribution on landuse and landform maps.The result of this research were a 1:10.000 map of gully distribution and density level of gully erosion in Kaliwungu Watershed. There were three density classes of gully in Kaliwungu Watershed which are high, medium, and low. The formation process of intensive gully only takes place at some intensively land cultivation points or at some land that has been highly disturbed by human activities. The result shows that landuse and land cultivation was the factors that influenced the formation of gully erosion.