Nidal Hadadin

Evaluation of several techniques for estimating stormwater runoff in arid watersheds

Several traditional techniques have been used for estimating storm-water runoff from ungauged watersheds. Some of these techniques were applied to watersheds of Rashadia in south-eastern desert of Jordan. When engineers apply rainfall-runoff models for hydrologic design, there are difficulties in defining and quantifying peak discharges that are required to design different types of hydraulic structures. The lack of data presents major difficulties for rainfall-runoff modeling in arid regions. These regions have characteristically high rainfall intensity and consequent flash floods. The specific objectives of this study are: (1) apply synthetic hydrographs for estimating peak discharges from limited hydrological data. (2) Evaluate the reliability of six techniques to accurately estimate storm-water runoff; and, to evaluate the runoff that is required to design hydraulic structures such as bridges, culverts and dams. (3) Estimate the flood resulting from direct runoff after subtracting all the loses such as: the infiltration, interflow and evaporation. (4) Develop a simple regression relationship between peak flow discharges and catchment areas. The results show that there is uncertainty in determining the accuracy of storm-water volume, this is due to several methods were utilizing the estimation the hydrographs base time, but promising results in predicting the peak flow discharge.

Rainwater harvesting in Jordan: a case of Royal Pavilion at Amman Airport

Volumes of rainwater harvested on-site are estimated by short-term storage capacity by two methods: graphical method and analytical method. The first method considers the difference between demand and supply over a specified period of time. The second uses random events to determine analytically, the storage capacity required to guarantee the draft. The comparison between the two methods indicates that there are minor differences. Based on the volume of water harvested after applying these methods, run-off coefficient for impervious surface in arid and semi-arid area was estimated. New analytical approach for long-term storage capacity is utilized to estimate the detention pond capacity off-site for the local natural streams. To apply this method, it is necessary to estimate the overall mean storage capacity in which the soil conservation service method is utilized. This technique is confirmed with graphical method.

Modeling of Rainfall-Runoff Relationship in Semi - Arid Watershed in the Central Region of Jordan

As a result of quick progression in computer and information technologies, computer modeling has become a vital tool in watershed research and management practices. Stanford Watershed Model (SWM) is an integrated physically based Watershed model that can be used to simulate water flow stream/canal network and overland runoff, interflow and evaporation by considering the interaction between surface water and subsurface water. The objective of this study is to apply the SWM in order to estimate the rainfall-runoff relationship for Wadi Wala streamflow semi arid area with an average annual rainfall of about 300 mm/yr and a catchment area of 1800 km. SWM has been widely accepted as a tool to synthesize a continuous hydrograph of hourly or daily streamflow. Sensitivity analysis, as well as trial and error adjustment techniques were used for the optimization of the number of parameters of the model. Comparing estimated and measured surface runoff for Wala valley indicated that the model is considerably efficient in predicting the total annual surface runoff from rainfall for similar watersheds.