Analisis Indeks Kekeringan Pada 15 Das Di Wilayah Jawa Timur Menggunakan Metode Ambang Batas (Threshold Level Method)

Abstract

Drought is a natural disaster that not known beginning and ending. This research have a purpose to analyze drought index and determine the zoning map drought index at 15 DAS in East Java 1996-2005 period. Drought index only observed about hydrological drought using water discharge data as a source analysis data. The Analysis of drought index using TLM method ( Threshold Level Method) with HydroOffice software . TLM method is used to determine the value deficit of water that occurred at 15 DAS samples. Drought occurs when the duration of water is deficit for 7 days. While, the mapping zonation drought index using IDW ( Inverse Distance Weighted ) with ArcGIS 10 software. From the analysis data, the drought index value is nothing impact with the extended DAS area. The biggest drought index value is 10,76 m vii

3 /s in DAS Wonorejo and the smallest is 0,06 m 3 /s in DAS Kadalpang. The zoning map classifies drought index DAS 15 samples into 4 regions based interpolation from drought index value. Zoning map classification drought index that is, 0–2,5 m 3 /s, 2,5–5 m /s and ≥ 10 m 3 /s.