Examining the Prediction Scenarios of Land Subsidence Caused by Excessive Extraction of Underground Water Resources of Tehran-Shahriyar Plain until the Horizon of 2031

Introduction: In recent years, the phenomenon of land subsidence, as one of the harmful effects of lowering the level of underground water, has always been the subject of discussion and concern of human societies. Therefore, this issue, along with the intensification of other challenges such as climate change, needs to find a solution. Scientific studies and subsequently designing and compiling various future researches to face possible future conditions with the least cost and economic and social damage. Shahryar Plain is one of the forbidden and critical plains of the country, which is also active in terms of industry and agriculture. This plain has been affected by the phenomenon of land subsidence for the past several years. The presence of vital arteries, economic, pilgrimage and military areas has turned it into a strategic area, which doubles the cost of the harmful consequences of subsidence. Therefore, it is very important to predict the possibilities of structural land by applying different conditions and probability of occurrence in different conditions to prevent and prepare to reduce its negative consequences in the way of implementing future water resource management plans.Methods: Using the geological, geotechnical and hydrological data of the plain in COMSOL software, the subsidence in 22 selected points of the study area was calculated during the years 2002-2018 and after verification and obtaining a high agreement with the real data and radar interferometric images, the amount of subsidence has been estimated till 2031.Findings: In this research, it has been tried to rely on the findings obtained from the prediction of the subsidence of the Tehran-Shahriar plain until the horizon of 2031 and based on the multiple scenarios in order to make policies. and provide guidance for future actions in the field of water resource and consumption management.Conclusion: The general result showed that the rate of subsidence in the early years appeared at a higher rate in the upper layers of the aquifer, and over time, after filling the voids between the soil particles towards the upper layers of the aquifer surface, and finally leads to the surface of the earth, the changes in the underground water level and the type of land have been among the factors affecting the subsidence pattern and rate