Reservoir Sedimentation Volume Changing Analysis of Pangsar Soedirman Dam Through USLE Based Rainfall Characteristics

Abstract

This research aims to analyse the reservoir sedimentation volume changing of Pangsar Soedirman Dam at Banjarnegara regency through rain erosivity and erosion analysis using universal soil loss equation (USLE) method. The catchment area of Pangsar Soedirman Dam reservoir has rainfall ranging from 1,500 - 5,500 mm/year. In 1989 and 1993, rainfall which has ranging from 3,000 - 5,500 mm/year did not make any increase of reservoir sedimentation volume. In contrast, with rainfall 1,500 mm/year in 1998, the reservoir sedimentation volume reached 6 million m3. Similarly, with rainfall 5,500 mm/year in 1999, the reservoir sedimentation volume decreased from 6 million m3 to about 4 million m3. These results show that the characteristics of rainfall in the catchment area do not always contribute to the increase of sedimentation volume in the reservoir but can also be influenced by other determinants other than rain

Keywords

• sediment yields
• reservoir sedimentation
• rainfall characteristics