Document Type : Subsidence as a global challenge: Crisis management or management crisis
MA Student in Remote Sensing, Department of Geomatics, Faculty of Civil and Transportation Engineering, University of Isfahan, Isfahan, Iran
Assistant Professor, Department of Geomatics, Faculty of civil and transportation engineering, University of Isfahan, Isfahan, Iran
Department of Geomatics Engineering, University of Isfahan, Isfahan, Iran;b Department of Civil and Environmental Engineering, Carleton University, Ottawa, Canada
Land subsidence induced by soil consolidation is one of the natural hazards that occur gradually. This phenomenon has reached its critical state in most regions of Iran. Factors affecting subsidence are groundwater level depletion, land cover, soil type, elevation, slops gradient, rock bed depth, etc. The causes of subsidence should be investigated so that decisions could be based on the real characteristics of the region. Decrease in groundwater level is one of the most important factors that influences subsidence but due to the complexity of the relationship between subsidence and other factors, a direct linear relationship between groundwater level and subsidence cannot be considered. The study aimed to investigate the relationship between subsidence and groundwater changes through relationship between the two parameters in the period 2014 to 2018 in Isfahan. In this regard, the time series of radar interferometry and the time series of water levels of piezometric wells in the Isfahan were studied. The results show that in 12% of the wells, no correlation exists, in 9%, poor positive ignorable correlation, in 12%, fair positive correlation, in 48%, significant positive correlation, in 6%, poor negative ignorable correlation, in 4% fair negative correlation and in 9% there is a strong and negative significant correlation between the subsidence rate and the groundwater level. Correlation values show the complexity of the relationship between subsidence and water level depletion. Therefore, the relationship between subsidence and its causative factors requires more detailed studies and comprehensive models.