Modification and Re-calibration of the Simulation Model of Lake Nasser

Abstract

In 1981, a mathematical simulation model for Lake Nasser (SMLN) was developed to test different hydrologic conditions and operation policies of the Aswan High Dam (AHD). At that time, AHD had been operating for around 12 years. Over the thirty years of the dam operation, the Egyptian water resources managers experienced cycles of floods and droughts. Also, data and information about the hydrologic parameters of the lake as well as the dam performance were accumulated. This by itself constitutes a good reason for re-calibrating of the SMLN. The 1998–1999 flood, which manifested the need to reconsider the dominant operation policy, also called for the adjustment and re-calibration of the SMLN or at least to retest its accuracy. This paper describes the effort carried out to recalibrate this model using few parameters and adjust its original mathematical formulation. Elements of the mass balance equation of the lake, which are uncertain and at the same time seem to have significant impact, have been used in the modification and re-calibration. The presented results show, in many cases, an improvement in the model performance and accuracy when compared with the original version calibrated in 1981. Nevertheless, these results should not be considered a final step in improving the model performance. Actual measurements of evaporation rates and piezometric heads of the groundwater around the lake may be used to formulate new and better loss equations

Keywords:

• Simulation model
• Aswan high dam
• calibration