Micro Catchments and Role of them to Soil Moisture Keeping

The water is life source and the main factor to human development. With increasing population and needs to food، day by day this needs to be evidence. Therefore، to prevent loosing this main source by planning should be done. One of the method to prevent from this lose is runoff control by micro catchments، keeping the moisture and reduce evaporation from soil surface. In this research، in order to introduce the most suitable method to reduce the evaporation from soil surface، to increase the perennial duration of soil moisture، to determine the performance of different treatments and to compare between them، lozenge shape micro catchments was made in sloppy hill side. The main duty of these micro catchments is collecting and conducting the surface water toward the end of the micro catchments and infiltrating the water into the soil which plus the humidity increase at micro catchments down، has considerable effects on increasing the level of the underground water tables and reducing the erosion and sediment production. In this research in order to increase the runoff coefficient، were made 6 treatments and 3 replications at the end of surface micro catchments were isolated by plastic cover so that end of each one of them has been isolated with common and available materials such as greenhouse plastic، gravel and fine and coarse sand and to infiltrate in depth of soil، a filter with 50 cm depth and 15 cm diameter was used. Soil moisture was measured and assessed in two depth 30 and 50 cm، during one year by TDR instrument. The result of research shows the treatment maximum or best treatment in purpose of soil moisture keeping in 30 cm depth is treatment b (plastic cover and gravel embankment) and in depth 50 cm are b، d (b+ with filter) treatments. The amount of keeping soil moisture resulted from kind of treatment than to control treatment in 30 and 50 cm depths are 2. 81% and 1. 62% respectively. The result of monthly variance shows b and d are the best treatments with 95 percent confidence in compare with other treatments. Because of low differences between in two treatment due to keeping moisture، and easy able and low cost، therefore b treatment is selected.