Estimasi imbuhan air tanah menggunakan metode simple water balance di lereng selatan Gunung Merapi, Yogyakarta, Indonesia

Abstract

One of the problems that faced by developing countries is the sufficient water supply. The rapid urbanization that caused by cultural activities, economics condition and education has made the massive use of groundwater, especially in Yogyakarta. Therefore, this study aims to estimate the groundwater recharge on the southern slope of Merapi Volcano using simple water balance method. This research was conducted in southern slope of Merapi that limited by Boyong river in the west and Kuning river in the east. The rainfall data was observed from CHIRPS satelite and annual temperature was observed from Yogyakarta Climatology Station (BMKG) in the last 10 years in the study area. The result show that average annual precipitation is 2785,685 mm/year, the result of evapotranspiration real is 1633,962 mm/year, and the result of runoff is 462,245 mm/year. After the calculation using simple water balance method, the recharge estimation is 689,478 mm/year. These groundwater recharge values were below the result that reported by previous studies.