MODELLING OF POTENTIAL RECHARGE ZONE USING GEOGRAPHICAL INFORMATION SYSTEM BASED ON INDONESIA REGULATION AND WATER BALANCE MODEL

Abstract

Recharge zone is an important aspect for sustainable water resources management. Recharge
are difficult to measure directly and the field-based methods are time consuming, expensive, and require large
number of skilled manpower. Application of remote sensing and geographical information system (GIS) has
wide application and good result in delineating recharge zone and various other fields. The present study aim
to delineating potential recharge zone using GIS based on Indonesia Regulation with comparison of water
balance modelling (NRECA and FJ Mock) in Cisadane watershed Indonesia. Water balance model is used for
generating rainfall data into monthly discharge (base flow and direct runoff) with validation of 3 discharge
station (Genteng, Batubeulah and Serpong) as representative of upstream, middle and downstream of Cisadane
watershed. Rainfall is a dynamic and sensitive factor for generating potential recharge zone, there is a
significant changing of potential recharge zone between using 3 parameters and 4 parameters, potential
recharge zone can increase or decrease based on annual rainfall. The accuracy of NRECA and FJ Mock model
and result fairly good validation with acceptable NSE (0.52-0.61) and R values (0.76-0.87). Potential recharge
zone map using 4 parameters (land use, slope, soil and rainfall) is suitable with the results of baseflow
percentage of NRECA and FJ Mock model. Cisadane watershed is dominated by medium (33.62%) to high
potential recharge (55.49%)