The impact of land use and land cover changes on soil erosion in western Iran

Analysis of long-term land use and land cover (LULC) changes requires up-to-date remotely sensed data to assess their effects on erosion. This is a particularly important assessment for regions with semi-arid landscapes where soils tend to be scarce and proper management necessitates matching LULC to local conditions to achieve sustainable land use. This study evaluates the impact of LULC changes on erosion using Landsat satellite imagery and the Revised Universal Soil Loss Equation model on the plains around the Jarahi River and the Shadegan International Wetlands. Supervised-classification and maximum-likelihood methods were applied to pre-processed TM, ETM, and OLI images for 1989, 2003, and 2017 to prepare LULC maps. The areal extents of agricultural land, wetlands, waterbodies, and built-up regions increased by 9.48%, 2.52%, 3.44%, and 0.13% from 1989 to 2003, respectively. During this timeframe bare (or barren) lands and wetland vegetation decreased by 11.44% and 4.13%. Between 2003 and 2017, however, the areas of bare lands, waterbodies, and built-up areas increased 12.77%, 1.52%, and 0.30%, while agricultural lands, wetlands, and wetland vegetation decreased by 9.99%, 1.32%, and 3.27%. According to the results, the areal extent of erosion at a rate > 1.1-5 Mg ha(-1 )year(-1) has been increased by about 45.56%, 50.06% and 52.24 between 1989, 2003 and 2017. LULC changes led to increased soil erosion on agricultural and bare lands. This highlights the need to plan and manage changes to LULC to reduce erosion to and below sustainable levels. Nature-based solutions can be effectively used to reduce erosion.

Automated summary

This study evaluated the impact of long-term land use and land cover changes on erosion around the Jarahi River and the Shadegan International Wetlands using Landsat satellite imagery. From 1989 to 2017, areas of agricultural land and built-up regions increased while bare lands and wetlands decreased, resulting in increased levels of soil erosion.