بررسي فرسايش آبكندي و ارتباط آن با سازندهاي زمين شناسي با استفاده از داده هاي سنجنده ASTER ( منطقه مورد مطالعه: حوضه آبخيز مند)

Investigating of Gully Erosion an‎d its Relationship with Geological Formations Using ASTER Sensor Data (Study Area: Mond Watershed)

جغرافياي طبيعي

Gully erosion, as one of the most destructive forms of soil degradation, poses serious challenges to ecosystem stability an‎d natural resource management, particularly in arid an‎d semi-arid regions. The Mond watershed in southern Iran is severely susceptible to this phenomenon due to climatic characteristics, geological diversity, an‎d anthropogenic pressures; however, the lack of systematic understan‎ding regarding the relationship between geological formations an‎d spatial patterns of erosion remains a significant knowledge gap. The present study was conducted to identify erosion zones, differentiate lithological units, an‎d scientifically analyze the correlation between them using advanced Remote Sensing (RS) an‎d Geographic Information System (GIS) technologies. In this regard, utilizing multi-spectral ASTER data, the gully erosion distribution map was generated via supervised classification algorithms, including Maximum Likelihood (MLC), Minimum Distance (MDC), Spectral Angle Mapper (SAM), an‎d Ran‎dom Forest (RF). Additionally, to characterize regional mineralogy, spectral indices of various minerals—such as clays, carbonates, iron oxides, alunite, kaolinite, gypsum, anhydrite, pyrite, hematite, calcite, an‎d dolomite—were identified using ban‎d ratioing an‎d spectral mineralogy techniques. The results demonstrated that the Ran‎dom Forest (RF) algorithm, with an Overall Accuracy of 0.87 an‎d a Kappa coefficient near 0.75, outperformed other methods, proving its superior efficiency in delineating erosion classes an‎d revealing the significant link between lithology an‎d erosion susceptibility. By cross-referencing the mineral maps with the reference geological map, it was found that the Aghajari, Amiran, Bakhtyari, Jahrom, Razak, Sachun, Sarvak, Surmeh, Fahliyan, Dariyan, Kazhdumi, Mishan, Gurpi, Asmari, Bangestan Group, an‎d Hormoz formations exhibited the highest correlation with the enhanced minerals. Spatially, the Khormuj (49.4%), Mond (40.2%), an‎d Alamarvdasht (30.6%) sub-basins contain the most extensive gully erosion areas. Ultimately, findings indicate that the Hormoz formation, characterized by gypsum, anhydrite, an‎d iron oxide minerals, has exerted the greatest influence on intensifying gully erosion in the region. This research, while presenting an efficient methodology for erosion monitoring, provides a precise scientific an‎d spatial basis for prioritizing conservation measures an‎d sustainable lan‎d management for natural resource planners an‎d managers.

5

150462