Spatio–temporal rainfall trend anomalies in Vidarbha region using historic and predicted data: a case study

Abstract

The present study aims to determine the temporal variations of rainfall trend in the Vidarbha region, India as a prerequisite for the flood–drought optimization of the area. Historic rainfall data from India Meteorological Department (IMD) and Indian Institute of Tropical Meteorology (IITM), Pune, were taken for a time period of 1951–2005 and is correlated. Data from IITM is a variable resolution Global Model, based on the Laboratorie Dynamique Meteorologie, France (LMDz). The correlation of LMDz model data with the IMD data was calculated using four statistical variables: Correlation Coefficient (CC), Normalized Root Mean Square Deviation (NRMSD), Nash–Sutcliffe Efficiency (NSE), and Skill Score (SS). Both data were further used for calculating the rainfall trend using non-parametric Mann–Kendall test and Sen’s Slope estimator and results were compared. There observed a good correlation between the data series from IMD and IITM. Hence projected rainfall data from IITM, for a period of 2020–2095 has been used to get a line about the future rainfall pattern of the area. The future rainfall trend scenario of Vidarbha is not favorable; hence proper water resources strategy should be defined to avoid desertification of the area.