Application of Guelph Permeameter to Evaluate the Hydraulic Conductivity of Saline Soils Contain Organic Matter (Case Study: Lake Urmia)

Drying a large area of ​​Lake Urmia is considered a serious environmental challenge for the region and the country. Therefore, the knowledge of the physical and mechanical characteristics of Lake Urmia bed material is necessary to do engineering activities to regenerate it. One of the major problems related to lake bed sediments is the effect of the high percentage of organic matter with low shear strength, high salt concentration, and solubility of some matters on soil behavior. In this article, after performing different field and laboratory tests to determine soil properties, the Guelph penetrometer (2800KI) was tested up to a distance of 1 km from the width of the lake and in different areas of the lake (Hyderabad in Naghadeh, Chichest in ​​Urmia and the ​​Urmia-Tabriz causeway). In these three areas of the lake, by digging 20 wells with a radius of 4 cm and a depth of 25-30 cm at different intervals in a zigzag pattern up to a length of 1 km towards the inside of the lake, hydraulic conductivity was measured using a Guelph permeameter in two hydraulic heads of 5 and 10 cm for each borehole with two replications. The study results showed that the hydraulic conductivity for the two areas of Hyderabad and Chichest of Urmia, on average, for loamy soils, mainly near the shore of the lake, was estimated to be 0.175 cm/h; 5.34 cm/h for layered sand and 1.89 cm/h for the ​​area around Urmia-Tabriz causeway.