GIS based MultiCriteria Decision Making MCDM technique to evaluate the suitability of land for irrigation in Khari River Basin

Abstract

Understanding the effects of climate change on land suitability for crop production has become an important issue with respect to food security. Agriculture plays a crucial role in the economic development, contributing to 14% of the national gross domestic product. However, this sector is facing various challenges, including climate change. This study applied a GIS based Multi-Criteria Decision Making (MCDM) technique to evaluate the suitability of land for irrigation in Khari River Basin for both baseline period (1990 to 2020) and future time horizons 2050s (2035 to 2065) and 2070s (2055 to 2085). Khari River basin is semi-arid and ephemeral; it is a tributary of Banas River, an important river of central Rajasthan (India). The planning process of irrigation has to integrate information about the suitability of the land, water resource availability and water requirements of irrigable areas in space and time. Key factors considered to evaluate the suitability of the land for irrigation include biophysical features (such as rainfall deficit, land use/cover, soil, and slope) and socioeconomic factors (such as distance to roads and population density). These factors were weighted using a pairwise comparison matrix then reclassified and overlaid to estimate the irrigation potential of the basin. Downscaled and bias-corrected future climate data from HadCM3 model under A2 and B2 scenario and CMIP6 model under SSP2-4.5 and SSP5-8.5 scenarios were used to represent the future climate horizon. As a result of climate change, on an average, rainfall will increase by 60 mm to 160 mm from the baseline period in the 2050s and 2070s. The average temperature shows a 2 to 5 ºC increase in the study area and a higher rate of increase is expected in the 2070s. Consequently, the rising temperature will increase the potential evapotranspiration by 15 to 45 mm in the 2050s and 2070s, respectively. The land suitability map was developed for irrigation was found to be 33% (2091 km2), 64%, (4072 km2), 3% (198 km2) for highly suitable S