Investigating the Trend of NDVI Changes Derived from MODIS Sensor Imagery (Case Study: Isfahan Province)

The present research aims to study vegetation cover degradation in Isfahan province, Iran using the MODIS sensor data. So, the 16-day images of the DNVI vegetation cover index of MODIS were used for 2010, 2015, and 2020. To precisely analyze vegetation, cover in Isfahan province and the counties of Khour va Biabanak, Aran va Bidgol, Isfahan, Semirom, and Fereydun Shahr, NDVI was categorized into four classes (0-0.1, 0.0-1.2, 0.0-2.3, and >0.3). Then, the variation trend of these classes was explored over a 10-year period. The results revealed an ascending trend of the 0-0.1 and 0.2-0.2 classes so that they reached from 62.93% and 32.65% in 2010 to 69.69% and 27.63% in 2020, respectively, whereas the 0.0-2.3 and >0.3 classes descended in the same period, changing from 3.69% and 0.74% in 2010 to 2.19% and 0.49% in 2020, respectively. The results of NDVI in the counties of Fereydun Shahr, Isfahan, Semirom and Khour va Biabanak showed the rising trend of the 0-0.1 and 0.1-0.2 classes and the falling trend of the 0.2-0.3 and >0.3 classes. The opposite was observed in Aran va Bidgol, i.e., an ascending trend in the 0.0-2.3 and >0.3 classes but a descending trend in the 0-0.1 and 0.1-0.2 classes. This can be ascribed to the expansion of arable lands. Vegetation cover degradation was fiercer in Semirom and Fereydun Shahr, possible due to the degradation of rangelands and forests by land-use change and excessive exploitation. Using the results of this study, it is possible to study the trend of vegetation changes in different regions of Isfahan province and adopt appropriate plans and policies on vegetation cover use.