Mohammad Faryabi

Land subsidence is one of the most important environmental threats in Iran. In this study, the risk of land subsidence in Jiroft plain in southeastern part of Iran has been investigated using fuzzy logic and geographical information system. For this purpose, hydrogeological parameters such as geology, soil type, aquifer type, saturated and unsaturated media, transmissivity, groundwater drawdown, aquifer thickness, groundwater pumping rate and distance to fault along with elevation, slope and land use parameters have been used. These parameters were standardized using fuzzy membership functions. Then different fuzzy operators were used to combine different parameters and prepare a land subsidence map. To validate the results of different fuzzy overly models, the spatial distribution of subsidence-induced fissures has been used. Based on the results, GAMMA 0.9 overly model is introduced as the best model for land subsidence risk zoning. According to the results of this study, the highest land subsidence risk is related to the eastern and southern half of Jiroft plain.