Rainfall analysis over 31 years of Chintapalle, Visakhapatnam, high altitude and Tribal zone, Andhra Pradesh, India

Climate change and variability impacting the monsoon dependent agriculture, particularly of the annual rainfall, effecting the rainfall pattern and distribution across India. The extent of the variability of rainfall varies according to locations. Consequently, investigating the dynamics of rainfall variables from the perspective of changing climate is important to evaluate the impact of climate change and adapt potential mitigation strategies. To gain insight, trend analysis has been employed to inspect and quantify the rainfall distribution in the Chintapalle, Visakhapatnam district of Andhra Pradesh, India. Thirty-one years for the period from 1990-2020 long historical rainfall data series for different temporal scales (Monthly, Seasonal and Annual) of the study region were used for the analysis. Statistical trend analysis techniques, namely Mann-Kendall (MK) test' was used to detect the trend. To compute trend magnitude, Theil-Sen approach (TSA) was used for calculation of Sen's slope. The detailed analysis of the data for 31 years indicates that there were rising and falling trends on various time scales in the study area and positive increasing trend for annual rainfall with 2.13 mm per year derived from linear regression. Departure analysis of rainfall indicated that a possible chance of normal rainfall, more frequently in the area. Rainfall Anomaly Index (RAI) analysis revealed that normal for most years. While the last ten years, the frequency of drought occurrence has thrice, but the magnitude is low. The annual Standard Precipitation Index (SPI) results showed that 2002 is a severely dry year. The study results will help in persuading the rainfall risks with effective use of water resources which can increase crop productivity and likely to manage natural resources by assisting the forecast systems for advance warnings to achieve sustainability at Chintapalle region of Andhra Pradesh.