Hydrodynamic Modeling for contaminant spills Case study: Nile River - Upper Egypt

Abstract

Most watercourses are subjected to the threats of contaminant spills. The Nile River is the main drinking and irrigation water source for all Egyptian cities around its banks, especially in Upper Egypt. The southern reach receives considerable amounts of agricultural, industrial and municipal wastes at different sites along its mainstream.
The goal of this research is to simulate contaminant spill in the studied part of the Nile River to determine the vulnerable area and assess the correspondent real travel time. Two scenarios of spill event were chosen and studied using the HEC-RAS hydrodynamic and water quality modules.
Following model calibration, the spill scenarios were run to simulate the transport of 500 tons of spilt phosphate into the Nile River. Results from the scenarios were compiled into a risk matrix in which spill characteristics are recorded at different downstream recipients. It was concluded that the travel time of spilt phosphate lies between 66 to 96 hours to cross the studied reach according to the flow condition. Risk assessment dealing with contamination crisis due to a spill event was provided. It enables decision-makers to plan for spill events mitigation actions, as well as, provides a quick response that can be taken immediately after a spill is detected. This assessment aids in understanding and studying the effects of spill on drinking water supply.