Rain water harvesting at eastern Sinjar mountain, Iraq

Iraq is facing water shortages and the problem is becoming more serious with time. The main water resources of Iraq (Tigris and Euphrates Rivers) suffer from severe reduction in their discharges due to construction dams on the both banks of Rivers inside Turkey and Syria. Agricultural land had been reduced drastically due to water scarcity. Despite this fact, none of the Iraqi farmers had yet used non-conventional techniques to augment water resources to overcome water shortage problems such as Rainwater Harvesting (RWH) technique.The main aim of this research is to contribute to solving the problem of water shortage of Iraq by finding effective results in terms of saving significant runoff water for irrigation purposes, and therefore provide an academic effort as a tool for encourage and decision support for RWH in Iraq.Macro RWH (large catchment area), was applied at East Sinjar Mountain in Iraq. The estimating volume of harvested runoff ranged (0.11-28.11) ×106 m3 calculated using the Watershed Modeling System (WMS) for the four selected basins together with total area of 435.14 km2 for the study period of (1990-2009).The results of estimating runoff volume showed that the runoff volume can be considered for irrigation practices especially in supplementary irrigation.A linear programming technique was adopted to maximize the irrigated area. Three scenarios of irrigation level were chosen: supplemental irrigation (SI) 100% Satisfy full irrigation requirements (S1), deficit irrigation (DI) 50% of full irrigation requirements (S2), and deficit irrigation (DI) 25% of full irrigation requirements (S3). The resultant irrigated area ranged between 18-2646 for SI 100%, 58-41303 for DI 50%, and 27-9543for DI 25% hectares respectively for all four selected basins together. These results reflect useful value of RWH and its influence to increase the irrigated area in the studied region. Godkänd; 2012; 20120720 (nadhir)