تحليل روند تغييرات پوشش گياهي استان اصفهان در نيم قرن گذشته با استفاده از سري زماني داد‌ه‌هاي ماهواره‌اي

Abstract Environmental and human factors have affected the quantity and quality of vegetation over time, and these changes will continue in the future. Temporal changes in vegetation may have increasing or decreasing trends, knowing these changes and their trends in the past and future can open the way for decision-making regarding landscape. This study aimed to eva‎luate the long-term temporal changes in vegetation condition in Isfahan province from 1972 to 2021. NDVI vegetation cover index and land surface temperature were extracted using MSS, TM, ETM+, and OLI sensor images of the Landsat satellite through coding in the Google Earth Engine (GEE) system. All processes were performed by applying coding in JavaScript and the Code Editor environment in the GEE. Rainfall data was also obtained from the PERSSIAN-CDR of the Irvine University of California Meteorological and Remote Sensing Base, and then the average rainfall data was calculated in ArcGIS software. Vegetation trends, temperature, and precipitation were obtained using non-parametric statistical methods of Mann-Kendall and Sen' slope tests via R studio software and trend calculation package. Finally, graphs of vegetation, temperature, and precipitation trends were plotted in Excel software. The time series analysis of vegetation cover, temperature, and precipitation showed that the vegetation index increased in Natanz, Aran va Bidgol, Kashan, Shahinshahr and Mimeh, Jarquyeh, Semiram, Chadegan, Isfahan, Lenjan, Varzaneh, Feridunshahr, Ardestan, Barkhar, Kohpayeh, Khansar, Tiran and Karvan, Dehaqan, Shahreza, Golpayegan, Fereidan, Mobarakeh. This increase indicates the improvement of vegetation in the north, northwest, and west to the southeast of the province. The reduction of vegetation cover in Khomeynishahr, the lack of precipitation in the province, and the further increase in temperature in Khour va Biabanak, Naeen, Buin and Miandasht, Flavarjan, Najafabad, and Herand, which include parts of the west, center, and east of the province, were the results of this study. The results showed that the eastern and central regions of the province are getting warmer. As a result, the temperature condition will become more critical, especially in Khomeynishahr, Dehaqan, Shahreza, Fereidan, Golpayegan, and Mobarakeh cities located in the northwest, west, and southwest of the province in the future. Relevant managers can consider these results in the departments of natural resources, agriculture, environment, and conservation and land affairs to adopt the necessary solutions and use in decisions and plans to deal with the condition of vegetation resulting from climatic and human factors in the province. Keywords: Vegetation cover, Land surface temperature, Rainfall, Mann-Kendall test, Sen's slope, GEE, PERSSIAN-CDR

رضا جعفري

سعيد پورمنافي , عليرضا موسوي