Land degradation trend in the climatic types of Fars province using remote sensing and climatic variables

Land degradation rapidly increased in developing countries. Changes in climate and land use in Fars province in the past few decades have intensified the process of destruction and desertification. In the present research, satellite data was used to investigate the temporal and spatial changes of vegetation and its relationship with climate changes in the climate samples of Fars province in the years 2000 to 2020. The trend of changes of these variables in time with the Mann-Kendall method and in determining the time of change and spatial correlation, Pettit's test and Pearson's correlation test were used, respectively. The trend of NDVI in arid and semi-arid climates is increasing and the point of change is from 2010 onwards. Based on this, it can be expected that in most regions of Fars, we see a decrease in the ratio of precipitation to potential evaporation (increase in evaporation) and the decadence trend is increasing. Precipitation has no trend and the surface temperature is decreasing. The spatial pattern of NDVI and precipitation trend is increasing in more than 70% of the region (south), and AI and LST are decreasing in more than 65% of the region (central). NDVI changes spatial correlation with LST, precipitation and AI variables showed that the type of relationship and the strength of correlation were different in climatic regions. The strongest correlations were seen in the cold ultra-arid climates in the northeast and the temperate Mediterranean located in the northwest of the province.