Document Type : Original Research Paper
Authors
1 Department of Geoinformtion and Geomatics Engineering, Facutly of Civil, Water, and Environment Engineering, Shahid Beheshti University, Tehran, Iran
2 Department of Surveying Engineering, Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran
Abstract
In Iran, unsustainable urban expansion and excessive extraction of groundwater resources have exacerbated and expanded the phenomenon of subsidence in metropolitan cities such as Tehran, Mashhad, Isfahan, and Shiraz. In particular, the urban areas of Shiraz, which have alluvial soils, high construction density, and a sharp decline in groundwater levels, have become one of the main centers of subsidence in the south of the country.
Considering the high capability of Sentinel-1 satellite radar data in analyzing land changes and the effective role of the DInSAR method in rapidly monitoring this phenomenon, the aim of this study is to analyze the spatial-temporal patterns of subsidence in urban areas of Shiraz, investigate the effective natural and human factors, and provide solutions to reduce risks and support sustainable urban development.
In this study, 24 Sentinel-1A radar images in IW mode with VV polarization were used in the years 2015 to 2025. All processing was performed in SNAP software. First, the data were orbitally corrected using POD files and then radiometrically calibrated to extract Sigma0. Lee filter with 7×7 window was used to reduce speckle noise. Then, by selecting 15 pairs of images with a time error of less than 365 days and a vertical spatial error of less than 150 meters, interferograms were generated and the Unwrapping process was performed with the MCF-SNAPHU algorithm. To reduce atmospheric errors, images with similar humidity conditions were selected, Goldstein filter was applied, topographic mask was used and variogram analysis was performed. Statistical analyses (mean, skewness, kurtosis, Moran’s I spatial analysis and multivariate regression analysis) were performed to investigate the effect of water withdrawal variables, soil type, construction density and land slope on the subsidence rate.
Main Subjects
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