Evaluation of the Environmental Quality of Semi-Arid Areas Based on Improved Remote Sensing Ecological Index (Case Study: Isfahan City, Central Iran)

This research was carried out to provide a suitable method to evaluate the environmental quality of semi-arid areas through the amendment of the Remote Sensing Ecological Index (RSEI). To determine the environmental quality of Isfahan City, Landsat images from 2002, 2011, and 2020 were used to extract five indicators of vegetation, humidity, dryness, heat, and salinity. Then, the Improved Remote Sensing Ecological Index (IRSEI) was obtained by Principal Component Analysis (PCA). The findings showed that the inhibiting effect of heat, dryness, and salinity indicators is significantly more than the promoting effect of vegetation and humidity indicators on the environmental quality of the study area. The average values ​​of IRSEI indicated a decrease in the environmental quality of Isfahan City. The area with poor and moderate environmental quality increased from 19372.77 and 14363.46 hectares in 2002 to 16527.51 and 12141.63 hectares in 2020, respectively. Excellent and good qualities were observed mainly throughout the vegetation around the Zayandeh-Rud River. Based on the results of comparing the land use map to IRSEI; Land use changes were identified as one of the main factors in reducing the environmental quality of Isfahan City. Moreover, vegetation increase, climate regulation, and human activities significantly improve the environment, although soil salinization has a negative effect that should not be ignored. It is suggested that factors such as meteorological conditions, biodiversity, airborne particles, and other human activities that may affect the environmental quality in semi-arid regions should be applied in future studies.