Determination of the lower permeability systems floodwater spreading using shallow sediment granolumetry Case study: Gachsaran Floodwater spreading station

In order to determine the amount of reduced permeability in the Gachsaran floodwater spreading station, sampling was performed at four points of the first and second strips of both channels and at a depth of 0-15 cm from the ground. Totally, samples were taken at 16 points. In addition, in order to determine the permeability changes of the spreading site, random sampling was performed in a place near the study site at four points with the same depth and no water spreading operations.Then, the samples were granulated with a series of standard sieves and the permeability of each point was estimated using the respective tables. According to the obtained results, permeability showed a significant reduction in flood spreading site, on average four times less than that of the start of the project. The reduced permeability of flood spreading areas is the most important limiting factor for implementation and maintenance of this type of artificial recharge projects.