Climatic trends and its impact on reference evapotranspiration and crop water requirement of rice crop in Arunachal Pradesh, India

Abstract

Arunachal Pradesh in one of the largest states in north eastern states of India, having subtropical humid climate influenced by monsoon. An attempt has therefore, been made to understand the climatic conditions of the state and its influence on the reference evapotranspiration (ETo) and crop water requirement (CWR) of rice crop, using 21 years (2001-2021) data of 14 districts of Arunachal Pradesh. The results revealed that the maximum temperature varied from 130C to 300C while minimum temperature varied from 30C to 200C and annual rainfall varied from 1200 mm to 2700 mm across the state. The maximum temperature was found to decrease while the minimum temperature and rainfall were found to increase with varying significant levels in different districts. The mean annual reference evapotranspiration (ETo) was found to vary between 900 mm and 1400 mm. The crop water requirement of rice estimated using CROPWAT model revealed a large spatial variation from 508 mm to 731 mm in different districts of the state.