نوع مقاله : پژوهشی
نویسندگان
1 محقق، موسسه تحقیقات خاک و آب
2 دانشیار پژوهش، موسسه تحقیقات خاک و آب کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
3 عضو هیئت علمی موسسه تحقیقات خاک و آب، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Land use and land cover (LULC) changes in Tehran, one of the most populous metropolises in the Middle East, have profoundly impacted environmental sustainability and natural resources. This study employed remote sensing data, including Landsat (TM, ETM+, and OLI) and Sentinel-2 imagery from 1991 to 2021, to investigate urban dynamics in Tehran. Images were sourced from Google Earth Engine and USGS platforms and pre-processed using geometric, radiometric, and atmospheric corrections via the FLAASH algorithm. To identify LULC patterns, Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built-up Index (NDBI) were calculated, followed by unsupervised classification using the K-means algorithm to delineate five primary land use classes: built-up areas, agricultural lands, orchards, barren lands, and water bodies. Subsequently, supervised classification methods, including Support Vector Machine (SVM), Minimum Distance (MD), and Maximum Likelihood Classifier (MLC), were evaluated, with SVM demonstrating superior performance (overall accuracy of 91% and Kappa coefficient of 0.89). Change detection using the post-classification comparison method revealed a 39.7% increase in built-up areas (from 410.36 to 573.51 km²), while agricultural and orchard lands decreased by 69.3% and 9%, respectively. This expansion, primarily towards western and southern Tehran, has led to the conversion of fertile agricultural lands into urban and industrial uses, posing risks such as intensified urban heat islands, diminished food security, and degradation of water and soil resources. These findings underscore the urgent need for sustainable urban policies, including the protection of remaining agricultural lands, promotion of vertical urban development, and integrated water resource management, to steer Tehran towards environmental sustainability and provide a model for other developing metropolises.
کلیدواژهها [English]