ANALYSIS OF THE EFFECT OF LAND USE CHANGES IN THE UPPER CITARUM WATERSHED ON THE SEDIMENTATION RATE OF THE SAGULING RESERVOIR WITH A SYSTEM DYNAMICS

• Main Author: Hidayat, Lukman
• Format: Theses
• Language: Indonesia
• Subjects: Teknik saniter dan perkotaan; teknik perlindungan lingkungan
• Online Access: https://digilib.itb.ac.id/gdl/view/70958
• Institution: Institut Teknologi Bandung

Land use changes in the Upper Citarum watershed due to rapid urbanization have led to the conversion of land into built-up land. The pattern of land conversion begins with the conversion of forests into bushland, which then turns into agricultural land and finally into built-up land. In 2020, agricultural land dominated the Upper Citarum watershed, covering around 31%, built-up land at 21%, and others around 24%. The forest area only covers 24% of the Upper Citarum watershed area. In data from 2006-2020, built-up land continues to increase in area. Meanwhile, new forests experienced a high increase in 2016- 2020. Changes in land use will affect erosion in the Upper Citarum watershed. The impact of high erosion causes an increase in the rate of sedimentation in the Saguling Reservoir. This study aims to analyze the rate of sedimentation in the Saguling Reservoir and the effects of changes in land use in the Citarum Upper Watershed. An analysis of land use change in the Citarum Upper Watershed was carried out by comparing each land use in 2006, 2011, 2016, and 2020. Forest and built-up land are types of land that are constantly increasing in the area in the 2006-2020 period. Erosion in the Upper Citarum watershed tends to decrease from 2006-2020. This is possible due to the increasing area of forest in the Upper Citarum watershed. In this study, the results of an SDR (Sediment Delivery Ratio) of 0,15% were obtained from the slope of the relationship between the erosion of the Upper Citarum watershed and the sedimentation rate of the Saguling Reservoir. Based on the results of system dynamics modeling with STELLA 9.1.3 Dead Storage software, the Saguling Reservoir will be full in 2061 with an average sedimentation rate until the year dead storage is fulfilled, which is 1,4 million m3 /year. There are four policy scenarios tested. The results of the policy scenario simulation, scenario 4 (full conservation of the forest) has a sedimentation rate of 900 thousand m3 /year and can make the Saguling Reservoir dead storage remain at the end of the modeling year.