APPLICATION OF SWAT MODEL TO ESTIMATE THE SEDIMENT LOAD FROM THE LEFT BANK OF MOSUL DAM

Abstract

Mosul dam is the biggest dam in Iraq on Tigris River. It is a multipurpose dam with a designed storage capacity of 11.11*109 m3. The Soil and Water Assessment Tool (SWAT) working with Geographical Information System (GIS) was applied to simulate the daily runoff and sediment yield from the seven valleys entering the reservoir from the left side. The model was applied for the period 1988-2008 based on daily climatic data of Mosul city and Mosul Dam Stations. The results indicated that the average yearly water flow was 13.8 *106 m3. It varies with time and among the valleys depending on the soil type, land watershed topography, watershed area in addition the other effective factors, and rainfall depth of that year. The resultant average annual sediment yield was 702*106 ton from these valleys. The sediment yield from each valley depends on runoff coefficient of the valley, soil type and plant cover. These factors affect soil detachment and rainfall properties (depth and intensity) that in turn affect rainfall detachment force. The total sediment yield for the considered period was 14753*103 ton. This represent about 0.42% of the dead storage of the reservoir (2.9*109m3) which is about 0.11% of the total reservoir storage capacity.