THE IMPACT OF LAND USE CHANGES ON EXTRIMITIES IN STREAM DISCHARGE AND WATER SUSTAINABILITY IN THE CISANGKUY WATERSHED-UPSTREAM CITARUM, WEST JAVA

• Main Author: Abizar Tasnim, Zharfan
• Format: Theses
• Language: Indonesia
• Subjects: Teknik saniter dan perkotaan; teknik perlindungan lingkungan
• Online Access: https://digilib.itb.ac.id/gdl/view/80315
• Institution: Institut Teknologi Bandung

Increasing population growth in the Bandung Regency, especially in the Cisangkuy Watershed area, has led to intensive land use change. Land use change affects runoff flow and discharge, thus impacting the sustainability of the Citarum River's water resources. Increased runoff will cause flooding during the rainy season. During the dry season, the base flow will decrease, causing a lack of water infiltration into the soil. These are commonly referred to as the discharge extremity phenomena. This research was conducted with the aim of assessing the hydrological function on extrimities in stream discharge as a result of land use change in the Cisangkuy Watershed. In order to determine the influence of land use on groundwater conservation, a conservation index analysis was conducted. The method carried out by scoring to the parameters of rainfall, rock type, soil type, topography, and land use, each of which has been assessed according to its influence on the ability to absorb rainwater. Based on the analysis, it is known that land use change in the period 2012-2022 has decreased the overall conservation function in the Cisangkuy Watershed area. The declining value of conservation function is indicated by the reduction of normal conservation criteria by 4.042,41 ha or 11.86%. The discharge extremities can be seen based on the maximum discharge value that increases in the downstream and the minimum discharge value that decreases in the upstream. Increasingly extreme discharge cause disruption of water resources infrastructure in the Cisangkuy Watershed area which is discribed by a decrease in minimum discharge and an increase in flood discharge in the period between regime of undeveloped and developed area. The application of environmental drainage systems and infiltration wells to restore hydrological function in Hari Residence Pangalengan shows the ability to absorb runoff discharge in return period 10 to 20 years and appropriated with zero runoff concept that will not interfere function of macro drainage/river.