STUDI TENTANG KEKERINGAN HIDROLOGI MENGGUNAKAN METODE AMBANG BATAS (THRESHOLD LEVEL METHOD)

Abstract

Lack of water availability to provide necessary water needs to sustain the life and surrounding environment can generate water deficit. For long periode of time the water deficit can propagate a drought event. Hydrological drought event definition as water deficit causing by inbalance between the need and availability of water on the river streams. This research aims to study the water deficit on the river flow and then the deficit are considering as hydrological drought. The study was conducting at 11 watersheds in East Java Province. Threshold level method and hydroofice software were using to evaluate the historical discharge data of the watersheds. the value of discharge at percentile 90 (Q90 ) using The threshold method. Daily discharge below the threshold for more than 7 days catagorized as deficit. The spatial distribution of water deficit amongs the watersheds occurs mainly during March to August.