“Desertification is a form of land degradation in arid, semi-arid, and semi-humid regions caused by climate change and human activities. The purpose of this research is to investigate the desertification situation in the Sirjan Plain region in the period from 1990 to 2023. Desertification in this area threatens human settlements. The purpose of this research is to combine several indicators to evaluate the state of desertification, and for this purpose, several spectral indicators are combined with each other to select the best indicator. In this research, based on albedo, MSAVI and SFI indices, desertification monitoring index (DMI) was proposed and the spatial and temporal distribution of desertification in the west of Sirjan was estimated in 1990 and 2023. To classify the results obtained from the DMI index, Jenks classification methods and quantitative index were used. Based on the results of the Jenks index, it was observed that the areas with very low desertification in 1990 were about 59.7 square kilometers, which decreased to 127.5 square kilometers in 2023, and 47.68 percent of the area has desertification. It has been very little. Areas with high desertification have faced a significant change and have reached 118.6 square kilometers in 2023 from 465.7 square kilometers in 1990. The results showed that Jenks classification method has a higher ability than the quantitative index with an overall accuracy of 82% and a Kappa coefficient of 0.86 in 1990. Finally, it was observed that the albedo index had the highest positive correlation compared to the DMI index. So that the correlation between these two indicators in 1990 and 2023 was estimated at 0.71 and 0.82, respectively.
 

In this research, due to the abundance of tectonic and karstic structures in the Prav Bisotun region, the relation between fault building and karstic springs was evaluated. To do this, we first prepare information layers including the location of the springs, the location of the closed holes, faults, the slope and the elevation floor layer, and then the graph of the grains of the faults is drawn and weighted by the weight of the evidence Was investigated. Investigation of the relationship between springs and faults in the Prav Bistuon region using the weighted method showed that there is a close relationship between tectonic elements and the frequency of springs, so that at low distances of the faults, the number of springs more and with The distance from the fault, the number and frequency of springs, is reduced. Also, the results of diagrams showed that faults have a direct effect on the origin and orientation of the springs. In the study of the relationship between the slope and abundance of springs, it was found that most of the springs were located on a gradient of 0 to 5 percent and elevations of 1200 to 1400 meters. The above altitudes cover the mountain slopes.