Design of a physically-based distributed parameter model for arid-zone surface-groundwater management

Abstract

A conjunctive-use study was conducted for the management of surface- and groundwater in the coastal aquifers of the Red Sea coast in Saudi Arabia. The objective of this study was to investigate the conceptual feasibility of implementing a good development strategy of surface- and groundwater in the region. The arid hydrology of the region and the agronomic practices and traditions of water allocation unique to the region required the design and development of a special model. This paper presents the analytical and numerical procedures that were used in the design of this special management oriented hydrologic model of the surface-groundwater system. The model was developed in three components, namely: (1) the surface-water conveyance model; (2) aquifer unsaturated flow model; and (3) the aquifer saturated flow model. A storage routing technique was used to model the surface flows in the wadi. Numerical techniques based on Green and Ampt type of solutions were used to model the vertical flow in the aquifer unsaturated zone. The flow in the saturated zone of the aquifer was modeled using the discrete-kernel approach of groundwater modeling. The complete model of the physical system was obtained by combining the three model components with the proper modeling of their dynamic interactions.