نوع مقاله : پژوهشی
نویسندگان
1 دانشجوی دکتری خاکشناسی، واحد علوم و تحقیقات تهران، دانشگاه آزاد اسلامی، ایران
2 استادیار، گروه خاکشناسی، واحد علوم و تحقیقات تهران، دانشگاه آزاد اسلامی، ایران.
3 استادیار، گروه جنگل، مراتع و آبخیزداری، واحد علوم و تحقیقات تهران، دانشگاه آزاد اسلامی، ایران
4 استاد تمام گروه خاکشناسی دانشگاه آزاد اسلامی واحد علوم و تحقیقات، تهران ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
In recent years, the irreversible phenomenon of land subsidence has led to environmental hazards in various plains of Iran including Gorgan. In general, the most important activities causing this phenomenon are inappropriate groundwater withdrawal and geological factors. The research method consists of two sections: identifying subsidence areas and examining the effective factors and parameters and evaluating the impact of each. In identification section, radar interferometry technique was used to compare the phase taken from two radar sets from the same region at two different times and measurement of land surface changes over time can be achieved through interferogram, and in the effective factors analyzing section, the determination and analysis of effective parameters such as water level drop, texture and thickness of soil layers, especially fine-grained layers were investigated. The results of the satellite data analysis indicate that the region is steadily subsiding. The mean velocity map along the satellite line of sight obtained from time series analysis showed a subsidence rate of 14 mm / month (169 mm / year). The identified subsidence range is approximately eastern-western which is consistent with trends in structures such as the Caspian. Figures of water level and precipitation in this area during 2007 to 2009 show a decreasing trend despite of seasonal fluctuations, and analysis of effective parameters shows that the subsidence is due to the same drop in water level or the difference of same thickness of the fine-grained layer at different depths
کلیدواژه‌ها [English]
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