Saad M. ALAYYASH , Jordan Badia Research and Development Program, PO Box 36, Jubaiha, Amman 11941, Jordan
Fidelia N. NNADI, Civil and Environmental Engineering, University of Central Florida, Orlando, FL 32816, USA
In Jordan as well as most of the developing countries located in the arid regions, water is a priority issue at national and individual levels. Several programs and management practices are in place to conserve water resources and implement new resources to meet the demand of various sectors of water users. With very high demand on the ground water resources, the limited surface water becomes a promising option for new and innovative water source. The limited rainfall amounts that fall over wide areas of the arid lands of Jordan (called the Badia) are of significant quantity and due to lack of proper management, the water is lost due to high evaporation rate.
In this study, HEC-1 modeling approach was used to estimate outflow volumes. This approach includes the Natural Resources Conservation Services (NRCS) Curve Number (CN), and unit hydrograph models. The surface runoff was simulated over the study area using the ArcView® software. ArcView® micro language, Avenue, was used to customize the Graphical User Interface (GUI) of the software. The simulation tool includes various steps of simulation used to estimate the runoff volume. The map data were accessed and displayed on the screen so the user can locate the catchment for further calculation. Other data files, which are the hydrologic database that describe the hydrology of the project area, also loaded.
Wadi Salma catchment (#11) were used to collect field rainfall-runoff data.
Rainfall storms were recorded in this catchment during December 2000 and April 2001
as well as the runoff volumes. These data with the hydrologic database were used in the
model to simulate the runoff and the results were compared to the observed field
observation. The results showed that the simulation model did simulate the runoff
volumes with acceptable estimation compared to the observed runoff. The model
calculated the peak discharge and runoff volume with acceptable accuracy for the whole
catchment (at Weir #1); the difference in peak discharge estimation was 2 -3% and in
runoff volume was 0% for the first storm and 20% for the second one.