Optimization of Rain Water Harvesting Systems.

The arid and semi arid climatic conditions cover up to 90 percent of Iran country amount and improper spatial distribution of rainfall has caused drought event and water shortage periodically. These phenomena act as a main problem against development. condition the lack of scientific and practical methods in optimal management of using precipitation are the most important problems in severity of soil erosion, water loose and also in the reduction of agricultural crops productivity. This technical report is an effort towards an implementation of feasible and suitable rain water harvesting methods. The main principles in this research are based on the results of the optimization rain water harvesting research project and its sub-projects which have been done by soil conservation and watershed management research institute in 11 provinces of Iran Using the results of above research projects has prepared suitable conditions to develop orchard trees in hillslopes. In general, in this report six important parameters have been considered. This report covers an integrated management for combination of mentioned factors that have important roles in the establishment of orchard trees in catchments factors are as follows: A- Designing microcatchment systems with the consideration of water requirement in minimum rainfalls. B- Designing gravelly filters with the aim of: B-1- Runoff quick infiltration in soil depths. B-2- conducting underground irrigation pattern using runoff. B-3- preparing suitable conditions for supplemental irrigation with the minimum water harvesting. B-4- decreasing water lost caused by soil evaporations. B-5- Increasing soil water content and expanding moisture C - Using Concept of undercurrent moisture component hillslope. D- Using different materials to increase soil water content. E- Using effective methods in decreasing the evaporation of soil surfaces. F- Implementation rain water harvesting systems and construction of cisterns with the aim of preparing water in critical times, supplemental irrigation and decreasing the danger of project break. In fact, the recent technical report characteristics is the presenting an innovative method in an integrated management of effective parameters in development of orchard dry farming mentioned methods in addition to preparing soil and water conservation programs will cause decreasing of poverty and increasing local economic enrichment.