Karakteristik Kekeringan Hidrologi di Wilayah Kalimantan Bagian Timur

Abstract

This study aimed to identify the hydrological drought using groundwater recharge component and analyze the relation between hydrological drought and ENSO phenomena. Water balance model with monthly rainfall and ETp input was used to assess the monthly recharge value from 1901 to 2009. In this study we used a monthly varying threshold method. The threshold varied depending on the climate regime and soil condition. Drought in groundwater was considered when the monthly recharge is below the drought threshold. We found that the longer drought duration, the volume deficit would significantly increase. Additionally, the longer drought duration, the number of drought events would significantly reduce. This study indicates that Samarinda region under peat soil and forest cover is more prone to drought as indicated by the highest drought frequency (56). In other hand, Banjarmasin region under mineral and forest cover is less vulnerable to drought. Furthermore, this study shows that peat soils are more pronounced to severe drought than mineral soils. Our findings also confirmed that strong El-Niňo would trigger severe hydrological droughts.