Climate change projections of rainfall and its impact on the cropland suitability for rice and wheat crops in the Sone river command, Bihar

Land suitability analysis is a necessity to achieve sustainable agricultural productivity with the optimum utilization of the available resources. Lack of proper knowledge on the best combination of factors that suit production of rice and wheat has contributed to low production in the Sone river command, Bihar. The aim of this study is to develop land suitability maps for rice and wheat crop based on physical, chemical and climatic factors of production using a multi-criteria evaluation (MCE) and Geographic Information System (GIS) approach. Biophysical variables of soil, climate and topography have been considered for suitability analysis. This work also evaluates the impact of climate change (CC) on cropland suitability for rice and wheat crops. Climatic variable scenarios of rainfall were obtained from four GCMs (CAN-ESM2, MPI-ESM-MR, CSIRO, CMCC-CMS) for three future time slices (2011-2040, 2041-2070, 2071-2100) of representative concentration pathways (RCP) RCP 2.6, RCP 4.5 and RCP 8.5 scenarios. The observation data (1985-2011) from IMD Pune from 8 meteorological stations were used as the current baseline climatic data of rainfall, which is used to validate the cropland suitability model. The results of CC indicate that there is a significant variability in the distribution of rainfall in the projected period 2011-2100 with respect to the baseline period. The results also show a concomitant increase in the projected crop suitability area of wheat from 17 to 35% and decrease in area for rice from 31 to 21% when compared with baseline for highly suitable area.