Association of Agrometeorologists

Assessment of rainfall trends at micro and macro level in Andhra Pradesh

V.U.M. Rao, B. Bapuji Rao, A.V.M. Subba Rao, N. Manikandan and B. Venkateswarlu

Climate change scenarios generated using GCM models are mostly based on grid data for the entire country or for a given state. Most international organizations use this data in generating the scenarios for India. An attempt has been made to make a comparison of rainfall trends based on 1° X 1° grid data and data collected from a dense network of 1128 raingauge stations in Andhra Pradesh. No decreasing trend is noticed over the entire state with grid data. However, a clear decreasing trend in annual rainfall is found in the tract consisting of Medak, Nalgonda, Krishna, East and West Godavari districts from block level data. On the contrary, increasing trend is noticed with grid data in these districts. In Prakasam district, declining trend in many blocks with block level data was noticed, but increasing trend is seen with grid data. Like-wise in Rayalaseema (Anantapur, Cuddapah, and Chittor) some blocks are showing increasing or decreasing trend with block level while with grid data, no significant trend was observed.

Rainfall trends, grid data, block data, Andhra Pradesh