Analysis of Rainfall in Assessing the Drought in Semi-arid Region of Karnataka State, India

Abstract

The present study focuses on drought analysis with an aim to understand the drought vulnerability, estimate and map the drought duration and severity in drought prone North Interior Karnataka region, India. A detailed analysis were carried out using rainfall data of more than 178 (with greater than 30 years data) stations to understand the drought characteristics. Rainfall descriptive variability, percentage occurrence of drought incidences and spatial distribution of rainfall were derived. In order to evaluate the drought severity and its extent and to map, method proposed by Ponce et al. (2000) and the Geographic Information System has been used. The method by Ponce et al. (2000) characterize drought based on intensity, duration and recurrence interval using mean annual precipitation of a location. The results obtained for the study area indicate that, the region is mostly semi-arid with drought occur for more than 50 % of the time. The majority of the drought events are of moderate intensity with few extreme intensity events. Further, it is noticed that, in many station, the rainfall show a decreasing trend. Since, rainfall in this region are mostly declining due to climatic change, the area would experience increasing drought severity in the forthcoming years. The outcome of the study would be useful in understanding the drought pattern, severity and extent in the study area which can be used by scientists and water management professionals to plan drought mitigation measures.