The effects of climate change and groundwater salinity on farmers' income risk

Climate change, in addition to reducing rainfall and increasing temperature, has led to a decline in water quality and increased groundwater salinity in Iran. These factors have a negative effect on crop yields. Therefore, the assessment of the effects of climate change and groundwater salinity on agricultural production is necessary. Hence, the object of this study was to investigate the effects of temperature, precipitation and groundwater salinity changes on farmer's income risk, water shadow price and economic, social and environmental indicators in Qazvin region. To this purpose, the sensitivity of crop yield to temperature, precipitation and groundwater salinity was estimated by using Response-Yield function and General Maximum Entropy method, then, these variables were predicted for 2030, 2040 and 2050 horizon. In the following, using the Target-Motad-PMP Model, the effects of climate and groundwater quality variables on economic, social and environmental indicators were simulated. Finally, using the multi-criteria decision-making approach, the most appropriate scenario of climate change was identified in Qazvin region. The results showed that climate change and groundwater salinity increasing have negative effects on income risk and water shadow prices. In the most pessimistic scenario, revenue risk and shadow prices will decrease by 11.2 and 20.3% respectively by 2050 horizon. The results showed that the environmental index with 43.8% is the priority of the farmers compared to the economic and social indicators. Also, among the environmental indicators, the water consumption sub-index is the most important in this region with 29.5%. Based on the TOPSIS ranking technique, the most appropriate climate scenario is the B1 scenario. It is suggested that B1 scenario be put on the agenda for adaptation to the climate change phenomenon in this region.