Physico-chemical properties of alluvial fan deposits at the Kowsar aquifer station

Kowsar station was implemented about 35 years ago in the Gareh Baygon plain of Fasa in Iran. Alluvial fan layer thickness, texture, permeability, total density, moisture, electrical conductivity and pH of sediments were investigated. The purpose of this study was to introduce suitable alluvial fans for floodwater spreading system and also to obtain the sedimentary properties of alluvial fans in the vertical column and a lateral comparison of its layers. After sampling, and experiments, the characteristics of the sedimentary layers of the three wells drilled in the alluvial fan were compared by the correlation method.The artificial recharge of the aquifer have changed the properties of the aquifer material in the depths.The infiltration clay has led to the formation of thin layers with a slight permeability (about 0.01 cm/m). The bulk density of sediments increased, their salinity increased and their acidity decreased, the calcium and magnesium cations increased and the moisture content of aquifer sediments increased significantly. Humidity, organic matter, micro and macro organic activity intensify the chemical weathering of sediment minerals.Generally, there are positive changes and there was no evidence of adverse effects of flood infiltration, such as the formation of saline interbeds or the formation of specific minerals. In arid regions, artificial recharge can not have a destructive effect on aquifers sediments. Provided that they are run in places without any special geological and sedimentary problems.