Mathematical model to simulate the surface runoff for Ubaiyidh valley in the western desert

Water plays an important role in human life and development. The evaluation, planning and management of water resources become important in sustaining human life, specially in arid and semi arid regions. This paper aims to develop a mathematical model to simulate the surface runoff for Ubaiyidh valley in the western Iraqi desert. The model also simulates the processes of interception storage, depression storage, infiltration percolation and inter flow. Two approaches are used for routing runoff. The first is time area curve which is applied to the wetted area, and the second is the Muskingum method for modelling the runoff in the main channel of the valley. The model contains ten parameters which have been optimized using Rosenbrcks method. The model parameters were calibrated by using available data.