Effect of drought on water quality and agricultural land value

In addition to yield, drought also affects water quality. Therefore, for long-term agricultural planning, the climatic situation of the regions must be determined. Therefore, in the present study, while evaluating the effects of drought on the quality of surface water salinity, the effects of drought and water salinity on the rent of agricultural lands were examined. For this purpose, by using SPI index, drought classes in the region were determined and by using QUAL2K model, water salinity was simulated in Taleghan river. Then, using Ricardian's approach, the effect of climatic, salinity and economic variables and their interactions on agricultural land rent were evaluated. The results of the QUAL2K model show that the drought has a direct and non-linear relationship with surface water quality, so that with decreasing river flow during moderate, severe and very severe drought classes, salinity decreases by 20.5, 41.3 and 57.8%, respectively. Based on the results of the Ricardin model, agricultural land rent is inversely related to water salinity and temperature, and is directly related to rainfall. The results of changes in the rent of agricultural land also showed that during the middle, severe and very severe drought classes, land rent decreased by 17.7, 32 and 42.4 percent, respectively. Therefore, it is suggested that farmers' compensation be determined on the basis of the amount of "lost rent", as it provides an accurate estimate of the actual amount of drought damage.