Understanding the climate change impact on crop yield over Eastern Himalayan Region: ascertaining GCM and scenario uncertainty

Abstract

It is well established that the adverse impact of climate change is going to affect every aspect of the ecosystem in the hilly terrain of the Himalayan region. Therefore, it is inevitable to assess the climate change impact on crop yield over the hilly terrain to undertake sustainable adaptation and agricultural practices. In the present study, Sikkim is considered as a study area, and crop simulation for three different crops (rice, wheat and maize) is carried out using calibrated AquaCrop with an available baseline dataset of 17 years (1998–2015). The future projections of different crop yields are obtained by using bias-corrected climate scenarios from four different global climate models (GCMs) under two different emission scenarios. Moreover, the uncertainty associated with the GCM and emission scenario is examined through the possibility theory. The outcomes from the simulations indicate an increase in the mean percentage change in the yield (0.5% to 20% for rice, 2% to 44% for wheat and 10% to 25% for maize) over Sikkim during 2021–2099. The increase in the mean yield can be attributed to the suitable temperature profile, increase in the CO2 concentration, high elevation of the study area and no significant water stress during the growing seasons of different crops and using the possibility approach indicates that during the recent past (2006–2015), the stabilized scenario is prevailing over the high emission scenarios in most of the cases. Our results facilitate the water and agricultural manager for considering proper and robust adaptation measures to ensure sustainability. © 2020, Springer-Verlag GmbH Austria, part of Springer Nature.