Drought Hazard Assessment in Ponnaiyar River Basin, India Using Remote Sensing and Geographic Information System

Due to the increase of water demand and threatening climate change, in the recent years have witnessed much focus on global drought scenarios. In India, Tamil Nadu have deficient rainfall (921 mm) compared to national average of (1200 mm) leading to over-reliance on irrigation for agriculture, and increasing extraction of groundwater reserves (estimates show over 60 percent of reserves are already exhausted) pose a big issue for the future and its indicate the continuing susceptibility of the society to drought. This study demonstrates the cumulative drought hazard assessment using climatic, biophysical and social factors in the Ponnaiyar River basin, Tamil Nadu, India. It was hypothesized that the key climatic, biophysical and social factors that define meteorological drought hazard, it is rainfall, normalized deviation of rainfall whereas for agricultural drought hazard were soils, geomorphology, drainage density, land use, and relief, and for hydrological drought hazard, it is lithology, depth to water table, and surface water bodies. The construction for the derivation of an agricultural, meteorological, and hydrological drought hazard map was created through the development of a numerical weighting scheme to evaluate the drought potential of the classes within each factor. A cumulative map created through spatial join of all the three types of drought provided a drought hazard scenario in totality. The area with different severity of drought hazards under cumulative drought hazards scenario is about 40% of the area under high to very high drought scenario. It is revealed the immediate attention have made to groundwater development for sustainable environment in the study area.