Multiple indices based drought analysis by using long term climatic variables over a part of Koel river basin, India

The present study demonstrates changes in vegetation pattern and climatic variability in past years in the parts of Koel basin in Jharkhand state of India by considering the spatial climatic variability, NDVI anomaly and satellite based drought indices viz Vegetation Condition Index (VCI), Temperature Condition Index (TCI) and Vegetation Health Index (VHI). Least square statistical method has been used for assessment of long term climatic fluctuation of major four climatic parameters viz maximum temperature of summer season, minimum temperature of winter season, rainfall of monsoon season, and solar radiation of Rabi and kharif season. Analysis of climate extremes has been done for 26 locations in the study area and then interpolated spatially in Geographical Information System platform. Long term NDVI anomaly shows adverse effect of climate extreme in past 20 years in the study area. The climatic variability exhibits that average maximum temperature during 1979-2017 fluctuates with an increase of 0.50-0.81 degrees C contrary to a decrease of 0.32-0.15 degrees C in various parts of study area. Similarly rainfall fluctuates with a decrease of 26-90 mm contrary to an increase of 19-230 mm. Drought prone zones as delineated from spatial overlaying map of VCI, TCI and VHI indicated value from 23 to 55. Major part of the study area severely affected by drought facing water scarcity and mediocre vegetation condition. These areas need proper planning and soil moisture management to overcome the recurrent drought conditions perceived in upcoming years.