Investigating the effects of land use changes on vegetation (Case study: Mian-Ab watershed in the period 2000-2020)

Abstract

Aim: The amim od this research is to investigate the effects of land use changes on vegetation in Mian-ab watershed in Shushtar city from 2000 to 2020. Material & Method: In this research, Landsat 5 and 8 satellite images for 2000 and 2020, respectively, were downloaded from the United States Geological Survey (USGS) website. After extracting the images, necessary pre-processing, including atmospheric, radiometric, and geometric corrections, was done on them in the Envi-5.3 software environment. To prepare the land use map, supervised classification algorithms, including maximum likelihood, minimum distance from the mean, parallel surfaces, and Mahalanoi distance, were used. Finding: The results show, in the period of 2020, changes in agricultural indicators (46.1%), range land (1.14%), water areas (1.54%), and a decreasing trend in rainfed lands (1.94%) and residential areas (3.63%) have an increasing trend compared to 2000. Dams, industrial centers, polluting factories, and temperature increases have caused most areas of good condition of vegetation indicators to become average. Conclusion: Based on the research findings, residential areas are rarely observed where the basin has a steep and slippery slope (15-30%) since leveling operations are not carried out in them. The natural situation and fluctuations in the height of the Shushtar watershed have produced a variety of plants. Innovation: The results of the conversion of agricultural and barren lands and lands that are already part of the river bed were applied, and the percentage of changes in the area of the index (SAVI) was lower than other indices, which is why the soil surface moisture of this index is affected by crop irrigation.

Keywords

• vegetation
• land use changes
• remote sensing
• shushtar miandoab basin