Extreme value analysis of annual precipitation in districts of Maharashtra, India.

India is dependent on rainfall for agriculture, food security and economic advancements. Spatial and temporal variability of rainfall is well reported, as well as the recent upsurge of extremes due to climate change. In Maharashtra, rainfall intensity varies widely from very high (coasts) to low (west-interior). Extreme value analysis (EVA) of heavy annual rainfall for the various districts of Maharashtra was conducted to ascertain the following for each district: suitable extreme value distribution; extreme (high) annual rainfall; efficacy of gap-filling for missing annual record/s. The suitability of various statistical distributions for representing high annual rainfall values was evaluated using Anderson–Darling test (quantitative), quantile and probability plots (qualitative). The gap-filling exercise resulted in minor variations (<10%) in the estimated extremes, positive as well as negative, for different cases. Therefore, the results of EVA on the actual records are advocated. The suitable distributions for 35 districts are presented in maps and Frechet distribution was adjudged suitable for almost 60% of districts. The estimated extremes for all districts are listed for different return periods for ready reference. These values would be useful for the planning and construction of hydraulic structures, water resources and reservoir management, design and planning of irrigation. Research highlights: Suitable probability distribution functions for modelling the extremes of annual rainfall in each district of Maharashtra have been identified and the parameters have been provided. Extreme values of annual rainfall for each district in Maharashtra for selected return periods have been presented. Evaluation was performed on whether the gaps in the annual rainfall records would affect EVA of the annual rainfall in the districts of Maharashtra. [ABSTRACT FROM AUTHOR]