Analysis of Forecasted Rainfall Across Blocks in Guntur District, Andhra Pradesh, India

Abstract

This paper represents a block and district level analysis of agro meteorological forecasted rainfall of Guntur district, Andhra Pradesh, during 2022-23. The forecasted rainfall data which was issued by IMD, Amaravathi, Guntur, Andhra Pradesh and the data was validated by employing both qualitative (success rate) and quantitative analysis (Ratio score, Hanssen and Kuipers Score and Probability of Detection). The quantitative analysis was performed by calculating ratio score analysis values ranged from 0.6 to 0.9 during the monsoons, indicating good forecast. Hansen and Kuipers score test results found to have good agreement during north east monsoon (0.5 to 0.8) with highest score values which indicates better forecast agreement, followed by monsoon period (0.3 to 0.5) and south west monsoon (0 to 0.3). Probability of Detection values found in the range of 0.7 to 1.0 indicated that better score values resulting in good forecast during the monsoon seasons. Whereas, the qualitative analysis was performed by deriving success rate for forecasted rainfall accuracy and the results reported that highest success rate was observed during north east monsoon followed by south west monsoon across different blocks and also in the entire Guntur district. The per cent deviation in the analysed data might be due to the spatio-temporal variations in the rainfall distribution pattern over the study area.