Identification needs and placement location of conservation building in upstream area with geographical information system

Abstract

The upper course of water catchment areas is buffer area for conservation at the watershed. In upstream area there are also regions where also suitable for planting a variety of agriculture commodities. The activity can cause the accurence of erosion and land degradation, so as to encourage of the flow of sediment to major rivers. The sediment carried by the flow of run off is to downstream so that causes silting-up of the grooves river due to sedimentation, that decrease capacity of flow the river and causes overflow of the river so there was a flood. Base on the problem, required building for conservation there is retaining sediment building on a grooves at the upperstream to hold and controling the flow of sediment. Therefor reguired to identification of the needs and right location to exact placement of the retaining sediment building. Because the nature of the land on the upstream area are hilly condition used geographical information system (GIS) to assist in identification of the needs and to determination of site the retaining sediment building. The purpose of the research is to prevent and control the flow of sediment that accur in upstream area and flow into the major river. The objective of the study is to understand the needs and appropriate location to placement of retaining sediment building in the watershed. Research methods that used is using geographical information system which combined with class and level of erosion and the technical requirement of retaining sediment building. The result showing that geographical information system can help in assignment the appropriate site of retaining sediment building in the grooves of upstream areas. According 29 catchment areas in the watershed, 17 of the region in accordance to putting retaining sediment building and 12 region other not appropriate. The number of retaining sediment building that can built in the watershed there was 22 location/points.