Impact of Extreme Weather Events on Wheat Yield in Different Agro-Ecological Zones of Middle Indo-Gangetic Plain

Abstract

The long period meteorological data of maximum temperature, minimum temperature and rainfall of Pusa, Purnia, Sabour and Patna stations representing different agro-ecological zone of middle Indo-Gangetic plain for the period (44–58 years) were analysed for trend analysis of temperature and rainfall for rabi season and heat waves, cold waves and extreme rainfall events for the whole year. The Theil–Sen’s slope and Mann–Kendall test were used to investigate the trends in climate variability (maximum and minimum temperature, rainfall) and extreme weather events (heat waves, cold waves and extreme rainfall). The maximum temperature had significant decreasing trend in Rabi season at Sabour. The minimum temperature had a significant increasing trend at all the stations in Rabi season. At Pusa, rainfall had a significant decreasing trend. Significant decreasing trend in heat waves at Pusa and Sabour stations were found. In this study, an attempt was made to assess the impact of these parameters on the productivity of wheat crop in Bihar. For this purpose, CROPSIM-Wheat model 4.6 was used to assess the change in wheat yield under different climate change scenarios for four locations viz. Pusa (zone I), Purnia (zone II), Sabour (zone III A) and Patna (zone III B) in Bihar. The model was run for the scenarios like increase in maximum temperature and minimum temperature with 1 °C, 2 °C and 3 °C separately and 1 °C, 2 °C, 3 °C, 4 °C increase in mean temperature keeping all parameters normal on wheat yield. Simulated wheat productivity revealed the reduction in grain yield by 7.4–10.4%, 15.3–21.2%, 21.6–30.9% and 26.9–38.6% in response to temperature rise by 1 °C, 2 °C, 3 °C and 4 °C, respectively, from baseline yield (1980–2010) at different locations. Warming temperature and greater incidence and intensity of extreme weather events due to climate change may significantly affect crop yield.