Investigating the effects of water transfer from Karkheh Dam on the physico-chemical properties of soil in Dasht-e Abbas plain, Ilam

Abstract

This research investigates the changes of soil properties in Dasht-e Abbas plain due to the Karkheh water transfer to this plain. In this<br />study, the maps of groundwater level changes before and after the utilization of irrigation system were prepared. Furthermore, to<br />investigate the changes of soil characteristics, soil samples were collected from various project implantations and control areas and<br />their parameters were determined and compared. The results showed that the groundwater level has been increased more than 15<br />meters during the study period and the depth of groundwater in some areas reached to less than 5 meters. The results indicated that the<br />highest salinity belonged to the network coverage areas and evaporating zone having a saturation extract electrical conductivity of<br />10.62 and 9.26 ds/m respectively, while dry land areas have the lowest salinity with electrical conductivity of 0.8- 4.0 ds/m. The results<br />further demonstrated that the water transfer of Karkheh Dam to Dasht-e Abbas due to the absence of drainage in 3 and 4 sub-networks,<br />high volume of agricultural return water from flood irrigation, and inadequate development of groundwater exploitation has reduced<br />the quality of soil in marsh area and flooding lands, and generally a "desertification" process after "combat to desertification" has<br />occurred