Meteorological Drought Assessment for Chittar Sub-Basin of Thamiravaruni River in Tamil Nadu Using Geographical Information System

Abstract

Drought is a normal, recurrent feature of climate and occurs in all climatic regimes and is usually characterized in terms of its spatial extension, intensity and duration. Drought causes economic, environmental and social impacts. Within a short period of time, the amount of moisture in soils begin to decrease which then leads to decrease in flow of rivers, water levels in lakes, reservoirs and wells after several weeks or months. As the economy of our country is often gripped with the gamble of monsoons, studies regarding drought become inevitable. Drought is caused due to deficiency of water that depends on rainfall, which falls in uneven pattern across the country. Hence, an attempt is made in the present study to analyse rainfall status and assess the drought severity of Chittar sub-basin in meteorological aspect using Geographical Information System (GIS). GIS provides tools to incorporate spatial and temporal variations of water resources data. The assessment of drought severity in the meteorological context was carried out by India Meteorological Department (IMD) method. Meteorological drought risk index for each rainfall station the sub-basin was calculated by frequency analysis. Spatial interpolation of meteorological drought risk index was mapped in Arc view GIS 3.2a software. The meteorological drought risk maps help the administrators and planners to plan various alternative measures to overcome the drought and its impacts.