Spatial Model for Ground Water Conservation Based on Landform Approach in the Southern Flank of Merapi Vulcano

Abstract

The urban City of Yogyakarta is the most densely populated with the highest number of population in the southern flank of Merapi Volcano, with the consequence of the highest water requirement. The southern flank of Merapi Volcano is an area with very high intensity of precipitation, however declining of groundwater table has occurred for quite of years with an average annual rate up to 30 cm. It is therefore, groundwater conservation effort is required. This research is aimed at; 1) constructing a hydrology spatial model based on landform approach on the research area to understand the water balance; 2) to find the area suffering from water scarcity and when the scarcity occurs; and 3) recommendation on groundwater conservation effort to overcome the water scarcity. The methods applied are to make a spatial model of the research area based on landforms and interfluves, water availabilty analysis, water balance analysis to find where and when the scarcity occurs, and the analysis for water conservation. The research area is naturally divided into 12 unit areas. The analysis has shown which unit areas, and when the water scarcity occur using water requirements of 120 liter/capita/day and 50 liter/capita/day. The proposed conservation efforts are applying rainstorm management.