Introduction: Discovering of the relationship between land use and environmental factors is the most important issue in ecosystem management and planning. In this study, an attempt is made to investigate the land cover changes in the forest and rangelands areas of Ilam province over the period from 2000 to 2024. This research was conducted with the aim of analyzing spatial and temporal changes in climatic parameters and land use, using images of MODIS sensor MCD12Q1 and ENVI 4.7, ArcGIS 10.1 in the Ilam province over the period from 2000 to 2024.

Materials and methods: Ilam province covers 20,150 km2, which accounts for 1.4% of the country's total area and is the 22nd largest province in Iran. This research was conducted with the aim of analyzing spatial and temporal changes in land use, using images of MODIS MCD12Q1 Satellite and ENVI 4.7, ArcGIS 10.1 in the Ilam province over the period from 2000 to 2024.In order to collect the field data, the available images from Google Earth for each year were taken as random sampling points. We use used MODIS land cover-type product (MCD12Q1, 500 m) for land cover information 2000-2024. In order to investigate the qualitative changes of land use, the land use map of the study area is classified and prepared using Density Slice method in 6 different floors including Urban and man-made areas, agriculture, wastelands, forests, pastures and water bodies. The supervised classification method (maximum likelihood algorithm) was used to achieve land cover classification based on ground truth in remote sensing.

Results and Discussion: The results indicate that 15/6% of the studied area experienced a decrease in rangeland vegetation, and 3/5% of the region's area has faced a declining trend in forest vegetation cover. Out of these, a total of 3,825 square kilometers of rangeland and forest vegetation were lost during the period under review. while the 6.4% increase in agricultural land indicates an exhibited growing trend. The findings revealed that over the past twenty-four years in Ilam Province, the growth of urban areas and human-made and urbanization development has increased by only 0.5%. This research used the MODIS MCD12Q1 yearly data at 500 m resolution to evaluate the spatio-temporal changes in the national land cover of Iran from 2001 to 2015 in five years’ periods. Land cover maps of Iran were generated based on 12 classes for years of 2000, 2005, 2010, 2015, 2020, and 2024 and then evaluated using Land Cover Change Table. Areal distribution analysis showed that the most parts of Ilam covered by barren areas (more than 40%). The area of rangelands and forests were reduced from 51.8 and 9.7 percent respectively in the year of 2000 to 36.2 and 6.2. percent of Ilam’s area in 2024. Furthermore, to evaluate land cover changes in five years’ period, the land cover map of the first and last years of each period were compared using Land Cover Change Table. Results showed that in the five years periods of 2000-2005, 2005-2010 ,2010-2015, 2015-2020 and 2020- 2024 land cover of Ilam’s rangelands and forests has decreased at an accelerating rate as 15.5 and 3.4 percent respectively of Ilam’s area.



Conclusion: The results of the analyses indicate a decreasing trend in forest and rangelands vegetation cover in the area of natural resources of Ilam province from 2000 to 2024. It can be concluded that the highlands of Ilam province, particularly the northern and eastern highlands, have witnessed a decrease in vegetation cover in forests and pastures. Also, low-altitude regions such as plains, lower elevations of southern and western Ilam, and especially areas surrounding cities and roads, have experienced a decline in vegetation cover. This decline can be attributed to human activities, including changes in land use and urbanization in Ilam province. These changes signify the loss of extensive vegetation and the exacerbation of detrimental impacts from both human activities and natural factors.