Abstract

Soil is a huge place for reserving rainwater from where it can be released gradually and with the lowest water loss. In an area where the soil does not exist or the soil thickens is negligible, the water capacity of the soil is quickly replenished. In arid and semi-arid zones, the rain intensity is high and rain distribution is low. Thus enormous amounts of rain are lost as flooding. Water spreading systems give enough time to spread the rainwater and to infiltrate deep into the soil. The Gareh-Baigan Plane, situated in Southern Fasa, in Iran's Fars province, is an arid zone often affected by floods. The water spreading project was designed for an area of 2500 hectares with the purpose of increasing rainwater content in the soil, artificial recharge of groundwater and improving environmental aspects. The total area affected by the project is about 7500 hectare. Using computer image processing of aerial photos and satellite imagery data of the area before and after the project shows the following:
-increased cultivated area due to utilization of more water from the aquifer
-improved rangelands and forest area due to a higher water content in the upper soil layers
-reduced wind blown lands and more desertification control due to vegetation developments
-reduced soil erosion, due to flood control, in the lower part of the area
-a pleasant and natural place was created in an arid zone.