An Investigation of Effective Factors on Groundwater Level Fluctuations in Western Anomalies of Sangan Iron Ore Mine

In order to design an appropriate dewatering system in an open pit mine, it is necessary to know the hydrogeological conditions and factors affecting the condition of groundwater in the mining area. One of the important factors for investigating the hydrogeological conditions of a mining site is to know the status of the catchment area, temporal and spatial changes of the piezometric levels and the range of disturbances caused by mining activities, climate conditions and the tectonic state of the mining area. The hydrological and hydrogeological conditions of Sangan iron mine are also affected by climate factors such as precipitation and tectonic factors including the number of faults and their trends, their distances and their relationship with each other. Therefore, in this study, the influence of various factors including precipitation, distance from waterways, tectonic status and faults, and the pit development during the exploitation period on the fluctuation of groundwater were investigated. By examining the fluctuations of the piezometric levels caused by these factors in the period from March 2011 to March 2014 and statistical analysis of the results, it was found that among the affecting factors, the Cn-pit expansion has the greatest effect on the groundwater level fluctuation of the western anomalies of Sangan mine. By drawing the ccorrelation diagram between the distance from Cn-Pit and the groundwater level drop of observation piezometers of the nearby areas of the Cn-pit, and obtaining a coefficient of determination equal to 0.94 (R2=0.94), it was found that the radius of the influence of the Cn-pit expansion on the changes in the groundwater level of the adjacent areas is about 700 meters. In addition, it was found that the amount of precipitation and the distance from the waterways do not have a significant effect on the groundwater level fluctuations in the study area.