It aims to simulate the stream flow, establish the water balance and estimate the monthly volume inflow to Simly Dam in order to help the managers to plan and handle this important reservoir.The Arc SWAT interface implemented in the Arc GIS software was used to delineate the study area and its sub-components, combine the data layers and edit the model database.
Agriculture in Pakistan uses well over 95% of the freshwater resources in addition to the high losses in the sprawling irrigation system.
Rapid and unsustainable development, too, has polluted and disturbed some major watersheds and river plains, Ali . Materials and methods Soil and Water Assessment Tool (SWAT) is applied to model the hydrology of Simly Dam watershed in Soan river basin.
The use of a watershed model to simulate these processes plays a 1110-0168 © 2015 Faculty of Engineering, Alexandria University. fundamental role in addressing a range of water resources and environmental and social problems.
The development of remote sensing (RS) techniques and Geographic Information System (GIS) capabilities has encouraged and improved the expanded use of watershed models worldwide.
SWAT is a river basin, or watershed, scale model which has the capableness to simulate both the spatial heterogeneity and the physical processes occurring within smaller modeling units, known as hydrologic response units (HRU) for the sustainable planning and management of surface water resources of rivers. Simly Dam is an 80 m high earthen embankment dam located in 33° 43' 08" N, 73° 20' 25" E at 30 km northeast of Islamabad and Rawalpindi in Rawalpindi District, Punjab and was constructed in 1983, IUCN Pakistan .
SWAT has been adjudged by researches as computationally efficient in its prediction, Neitsch et al. It has a reliability which confirmed in several areas around the world. It was tested and used in many regions of Africa by Fadil et al. Simly Dam catchment area receives heavy precipitation in the form of snow and rainfall. A watershed is comprised of land areas and channels and may have lakes, ponds or other water bodies. The flow of water on land areas occurs not only over the surface but also below it in the unsaturated zone and further below in the saturated zone, Singh and Frevert . This is an open access article under the CC BY-NC-ND license ( These results revealed that if properly calibrated, SWAT model can be used efficiently in semi-arid regions to support water management policies. This is an open access article under the CC BY-NC-ND license ( Introduction Water is an essential element for survival of living things. © 2015 Faculty of Engineering, Alexandria University. It is vital factor for economic development and augmenting growth of agriculture and industry especially in the perspective of rapidly increasing population and urbanization. The model was calibrated from 1990 to 2001 and evaluated from 2002 to 2011.Based on four recommended statistical coefficients, the evaluation indicates a good performance for both and validation periods and acceptable agreement between measured and simulated values of both annual and monthly scale discharge.The balance between population and available water already makes Pakistan one of the most water stressed countries of the world. The problem of increasing water scarcity in Pakistan is multifaceted. Many zones face scarcity of freshwater or subject to pollution. Thus, the availability and the sustainable use of the water resources become the core of the local and national strategies and E-mail address: [email protected] review under responsibility of Faculty of Engineering, Alexandria University. To deal with water management issues, one must analyze and quantify the different elements of hydrologic processes taking place within the area of interest. Arnold, The soil and water assessment tool: historical development, applications and future research directions, Trans.