Zoning and Analysis of Temporal and Spatial Changes in Gully Erosion and Its Impact on the Villages of the Mond Watershed during the Years 2000 to 2024

Sustainable land management and adopting preventive strategies to control gully erosion are crucial for mitigating its negative impacts on communities and the environment.Gully erosion, especially in arid and semi-arid regions, can lead to severe consequences such as agricultural land degradation, reduced land productivity, and environmental risks.The Mond watershed in southern Iran, with its unique geographical and climatic characteristics, has become increasingly susceptible to gully erosion due to climate change, population growth, and land use changes.Villages within this watershed, as essential components of local communities, are directly affected by this process.Temporal and spatial changes in gully erosion zonation from 2000 to 2024 have not only influenced the environmental conditions of the region but also affected residents' livelihoods and rural development sustainability.Identifying and analyzing spatial patterns of these changes can contribute to better natural resource management and more effective planning to mitigate adverse impacts. 2-MethodologyThis applied research aims to assess land use changes and gully erosion risk zonation in the Mond watershed during the years 2000 and 2024.The methodology is based on spatial and temporal analysis of remote sensing data and the application of Geographic Information Systems (GIS) combined with satellite image processing.Data collection involved Landsat 5 (2000) and Landsat 8 (2024) satellite imagery, which were acquired and processed via Google Earth Engine.Elevation data from Digital Elevation Models (DEMs) and climatic information such as temperature and precipitation were extracted from reputable global databases.For data analysis, atmospheric corrections were applied to the satellite images, and land use maps were classified using the Random Forest algorithm into five main classes (agricultural land, rangeland, forest, barren land, and urban areas).Subsequently, slope, elevation, precipitation, and temperature layers were prepared in GIS and integrated with land use layers.These datasets were used to produce gully erosion risk maps. 3-ResultsIn 2000, areas with higher precipitation were concentrated in the northern and central parts of the watershed.By 2024, precipitation in these regions had decreased, potentially reducing gully erosion risk in some areas.However, the cumulative effects of past erosion remain evident in the region.Changes in slope and geological formations have also influenced erosion trends.Areas with steep slopes and marly or shale formations are more prone to gully erosion due to the high sensitivity of their soils to rainfall and surface runoff.Many villages are located near areas with a high risk of gully erosion, particularly in regions with weak vegetation cover or limited surface water resources.High-risk areas in 2024 account for 1% more of the watershed's area compared to 2000.This increase is likely due to vegetation degradation, new construction, or climatic changes exacerbating erosion.Between 2000 and 2024, lowrisk areas have slightly increased, but the percentage of villages within these areas has decreased.Conversely, moderate-risk areas, despite a slight decrease in area, now host a larger proportion of villages, intensifying pressure on these zones.While high-risk areas have expanded, the number of villages exposed to these risks has not changed, but the spread of gullies and associated threats must be taken seriously.Implementing management and protective measures can mitigate risks and ensure the safety of