A Hydrostratigraphy Survey to Identify Groundwater Potential Zones, Using Geophysical and Sedimentological Data Integration: A Case Study of Kurdan Plain, Karaj, Iran

In this study, it was tried to identify the most important aquifer in Kurdan plain, karaj area, using hydrostratigraphic, hydrogeologic and sedimentological data. To this end, in the first place, Kurdan alluvial fan as the most important aquifer in the area was investigated using geological investigations and translate the geological sections to the hydrostratigraphic units. Geophysical maps such as iso-resistivity, iso-thickness and iso-depth maps were utilized to identify the aquifer geometry. Next, alluvial fan grain-size analysis and assessment to the hydrogeological properties of aquifer were studied by sediment samples analysis. The results showed that as we move away from the origin of the sediment, although the thickness increases, the discharge and the water quality decrease. Higher uniformity coefficient of grain size distribution curves in median zone of the alluvial fan indicates that hydrogeological properties of this zone are appropriate for groundwater extraction. Finally, using some parameters such as resistivity, bed rock depth and uniformity coefficient and via expert weighting and analytical hierarchically process, potential of water extraction map was prepared. The results showed that the median zone of alluvial fan has an acceptable water extraction potential.