Determination of Hydrologic Soil Group from Soil Map Unit of Indonesia in Pataruman Water Catchment Area

Abstract

Hydrologic Soil Group (HSG) for each region is different depending on soil conditions. It is one of the key elements in the NRCS-CN determination to account for the rain-runoff relationship. But unfortunately in Indonesia there is no map of HSG. Adidarma (2013) has conducted the research about HSG determination by using hydrogeology map. However, the map has a long process of pedotransfer and HSG parameter approach is still generally and qualitative. Furthermore, Ramadan (2017) has done research of HSG determination with HWSD map; the map is a global map which depth of information type of soil is less profound. Related to those problems, the researcher will conduct the determination of HSG in accordance with the condition of land in Indonesia by using Land Map Unit (SPT) Indonesia. HSG will be overlay with the transparent of land in Pataruman Water Catchment Area (WCA) until obtained the value of NRCS-CN and then the discharge plan will be calculated and will be calibrated with debit recording in Bendung Pataruman.