The Impact of Land Use Change on Water Resources in The Southern Foot Plain of Merapi

Abstract

Population growth has resulted in the increase of settlements. Settlements in urban areas are getting crowded, including many hotels that require abundant water supply. Groundwater needed by the population is huge. Settlement constructions cannot be stopped. The next target area is land outside the urban areas. Some areas outside the northern urban areas are water catchment areas, the southern slopes of Merapi. Based on these problems, the major changes of land and river flow coefficient, one of the rivers on the southern slope of Merapi are studied.The sample of the research is the river flow area of Code. The Code catchment area shape extends from the south to north. The flow coefficient is calculated based on the comparison of annual water volume between 2003 and 2012. This year sampling considers data completeness, land use data, rainfall data, and current data in Pogung Automatic Water Level Recording (AWLR).The results show that a change in land use over the past 10 years has occurred. The total volume of river water in 2003 was 15.3 cubic meters, while the volume of flow in 2012 was 41.7 cubic meters. The value of the flow coefficient in 2003 was 0.262, while the flow coefficient in 2012 was 0.636. This research suggests that it requires to be built 180,400 recharge wells. The artificial recharge model is adapted to the topography, groundwater depth, and infiltration of each region.