Wadi Flow Simulation Using Tank Model in Muscat, Oman

Abstract

In Oman, changes in precipitation intensity and frequency have already begun to be detected, although the attributed impacts, such as, flash flooding is poorly understood. For example, the supper cyclonic storm, hurricane Gonu in 2007 led to the worst natural disaster on record in Oman, with total rainfall reached 610 mm near the cost. The cyclone and flash flood caused about $4 billion in damage (2007 USD) and 49 deaths. The objective of this study is to develop a Wadi-flow simulation model to understand precipitation-river discharge relationship in Muscat. A lumped-parameter, non-linear, rainfall-runoff model was used. The Food and Agriculture Organization (FAO-56) modified Hargreaves equation was used for estimating reference evapotranspiration (ET0). Precipitation and temperature data during 1996-2003 were obtained from the Muscat-airport meteorological station. Observed river discharges during 26-30, March 1997 were used to calibrate the model and observations during 1997-2003 were used to verify our simulations. Simulated water discharges agreed with the corresponding observations, with the Nash–Sutcliffe model efficiency coefficient equals to 0.88. This developed model will later be used with a set of General Circulation Model scenarios (GCM) to understand the Wadi-flow variations under changing climate conditions.