Characteristics of Watershed For Determination of Critical Land Management: Application of Model Of Soil And Water Assesment Tool In Sub Watershed Ciseel, Watershed Citanduy, West Java Province, Indonesia

Abstract

Sub watershed Ciseel is one of the sub watersheds in the area of watershed Citanduy which exhibited important role in the life and economy of the people. The objectives of this research  were to learn the productivity level of sub watershed Ciseel to produce water, and to learn the sediment yield which affected the quality of Ciseel river. Data analysis used Soil and water Assesment Tool (SWAT). Research results showed that most ( around 46%) of Ciseel river flow in the upstream, middle and downstream part, came from surface runoff. Of the sub surface flow, lateral flow was more dominant as compared with ground water flow in the upstream part. Contribution of lateral flow was around 29,9%, whereas that of groundwater flow was around 24,5%. For the middle part, ground water flow (29,5%) was more dominant as compared with lateral flow (23,7%). Unlike with downstream part, comparison between groundwater flow and  lateral flow, shows that they were relatively similar, namely around 23.3%. Sediment yield in sub watershed  Ciseel was still categorized as safe. Around 98.12% of the sub watershed Ciseel area, exhibited sediment yield less than 60 tons/Ha/year. Land with erosion rate of more than 60 tons / ha/ year in sub watershed Ciseel was approximately 1402 hectares. The greatest sources of erosion came from bare land, dry land agriculture and shrub land in slope of more than 15%.

Keywords: Sub  watershed Ciseel, sediment yield, surface flow, groundwater flow, lateral flow, SWAT