Rainfall Floods as a Result of Land Use Alteration in a Syrian Refugee Camp in Jordan

The Zaatri Refugee Camp (ZRC) established summer 2012 shortly after the Syrian conflict started. Due to high flux of refugee fled the conflect south of Syria to Jordan and in a short notice, the international organizations with the Government of Jordan started to establish the camp with limited data on socio-economic and environmental impacts of the selected site. The camp is located in a nearly flat area which forms natural soil pan that used for cultivation. One of the environmental impacts for the selected site is the flooding in parts of the camp due to altering the hydrologic response of the area. This alteration is resulted in two ways: the first on is the building of earth wall around the camp which stops the runoff floods from getting into the natural water courses, the second alteration is the building of dense metal houses with compacted pathways in between. After establishing the camp, the land use changed completely, dense metal housings are built covering around 50% of the area. Networks of compacted roads between the housing blocks are built using imported crushed limestone aggregates. The change in land cover increased the Curve Number (CN) from 84 for the natural agricultural land to 92.5 for the built up area. The increase in CN due to altering the hydrologic parameters within the camp area increased the runoff depth by 82% to 614%, this resulting in more flood water trapped inside the boundaries of the camp. The flood volumes that accumulated can cover more than 10% of the camp area with average water depth 25 centimeters (cm) for 25-years return period storms. In other hand, the storms event that most probably occurs every other year (2-years return period) could result in flood that covers about 1.5% of the camp area with water depth that reaches 25 cm. Keywords: Rainfall floods, Land use alteration, Zaatari Refugee Camp, Jorda

Hydrological and Hydrodynamic Modeling for Flash Flood and Embankment Dam Break Scenario: Hazard Mapping of Extreme Storm Events

Simulation of dam breach scenarios can help in the preparation of emergency action plans for real dam breaks or flash flooding events. The purpose of this study was to identify flood-prone areas in the Al Wala Valley in the governorate of Madaba in Jordan through analysis of the Al Wala Dam. Modelling of dam breaches was conducted under two scenarios: a Clear Day scenario and a Probable Maximum Flood (PMF) scenario. The former scenario does not address the various dam failure modes; rather, it addresses the formation and development of a breach as a result of structural failures like the sliding of dam blocks in the case of a concrete dam or piping failures in the case of embankment dams. The PMF scenarios, however, simulate unsteady flow in pipes and overtopping failure via consideration of runoff hydrography. In the PMF scenario, flood-prone areas can be identified by in-depth analysis of data from previous extreme rainfall events. The related hydrologic and hydraulic data can then be modelled using intensity-duration-frequency curves applied to an hour-by-hour simulation to discover the areas most at risk of flooding in the future. In the present study, data were collected from inlet of flow to Al Wala Valley on 10 January 2013. The collected data, which included rainfall and discharge data, were fed to the HEC-HMS software in order to calibrate the hydrological parameters of the watershed of the Al Wala Dam. Additionally, the HEC-RAS tool was employed to determine the breach outflow hydrography and hydraulic conditions across various critical downstream locations, which were determined by use of dynamic flood wave-routing models. The simulations revealed that, in the case of the Clear Day scenario, downstream inundation would cover an area of 5.262 km2 in the event of a pipe failure. However, in the event of a six-hour storm, a twelve-hour storm, and a twenty-four-hour storm, the flooded area would rise to 6.837 km2, 8.518 km2, and 9.390 km2, respectively. In the event of an overtopping failure, 13.171 km2 would be inundated, according to the Clear Day scenario. On the other hand, in the event of a six-hour storm, a twelve-hour storm, and a twenty four-hour storm, the flooded area would rise to 13.302 km2, 14.249 km2, and 14.594 km2, respectively

Hydrological and Hydrodynamic Modeling for Flash Flood and Embankment Dam Break Scenario: Hazard Mapping of Extreme Storm Events

Simulation of dam breach scenarios can help in the preparation of emergency action plans for real dam breaks or flash flooding events. The purpose of this study was to identify flood-prone areas in the Al Wala Valley in the governorate of Madaba in Jordan through analysis of the Al Wala Dam. Modelling of dam breaches was conducted under two scenarios: a Clear Day scenario and a Probable Maximum Flood (PMF) scenario. The former scenario does not address the various dam failure modes; rather, it addresses the formation and development of a breach as a result of structural failures like the sliding of dam blocks in the case of a concrete dam or piping failures in the case of embankment dams. The PMF scenarios, however, simulate unsteady flow in pipes and overtopping failure via consideration of runoff hydrography. In the PMF scenario, flood-prone areas can be identified by in-depth analysis of data from previous extreme rainfall events. The related hydrologic and hydraulic data can then be modelled using intensity-duration-frequency curves applied to an hour-by-hour simulation to discover the areas most at risk of flooding in the future. In the present study, data were collected from inlet of flow to Al Wala Valley on 10 January 2013. The collected data, which included rainfall and discharge data, were fed to the HEC-HMS software in order to calibrate the hydrological parameters of the watershed of the Al Wala Dam. Additionally, the HEC-RAS tool was employed to determine the breach outflow hydrography and hydraulic conditions across various critical downstream locations, which were determined by use of dynamic flood wave-routing models. The simulations revealed that, in the case of the Clear Day scenario, downstream inundation would cover an area of 5.262 km2 in the event of a pipe failure. However, in the event of a six-hour storm, a twelve-hour storm, and a twenty-four-hour storm, the flooded area would rise to 6.837 km2, 8.518 km2, and 9.390 km2, respectively. In the event of an overtopping failure, 13.171 km2 would be inundated, according to the Clear Day scenario. On the other hand, in the event of a six-hour storm, a twelve-hour storm, and a twenty four-hour storm, the flooded area would rise to 13.302 km2, 14.249 km2, and 14.594 km2, respectively

Spatial mapping of groundwater springs potentiality using grid search-based and genetic algorithm-based support vector regression

In this study, groundwater springs potentiality maps were prepared using a novel integrated model, support vector regression (SVR) with genetic algorithm (GA), for the Jerash and Ajloun region, Jordan.The conditioning factors such as altitude, aspect, slope angle, plan curvature, stream power index, topographic wetness index, length of slope, distance from drainage network, lithology, distance from faults, land use and normalised difference vegetation index were considered to map the groundwater spring potentiality. GA was used for two purposes. First, GA was used to optimize the hyper-parameters of the radial basis function (RBF) kernel of SVR model. Second, GA in combination with SVR was used as feature selection (FS).The results of these models were compared with common grid search (GS) method used in most of the studies. The GS method was employed to calculate the parameters related to the SVR model and also hyper-parameters of RBF kernel. The results show optimum values of the kernels in the SVR model and selecting the optimal features which have the most contribution in modeling were the major steps in modeling and also in achieving a desirable precision level

Novel hybrid models combining meta-heuristic algorithms with support vector regression (SVR) for groundwater potential mapping

This study aims to develop three novel GIS-based models combining Genetic Algorithm (GA), Biogeography-Based Optimization (BBO) and Simulated Annealing (SA) with Support Vector Regression (SVR) for groundwater potential (GP) mapping in the governorate of Tafillah, Jordan. Twelve topographical, hydrological and geological factors were considered. The mapping process was done with and without feature selection (FS) conducted by integration of SVR model with GA, BBO and SA algorithms. The accuracy of these models was evaluated using the area under receiver operating characteristic (AUROC) curve. Comparisons among the models uncovered that the SVR-RBF-GA and SVR-RBF-BBO models performed better than the SVR-RBF-SA. The AUROC for two mentioned models were 0.964 and 0.996 in training and testing runs, respectively, while this metric was 0.953 and 0.986 for SVR-RBF-SA model in training and testing runs, respectively. The results showed that after FS, the models are more accurate in test data than train data

Preliminary Geophysical Investigation for Suggested Water Harvesting Sites in the

Abstract: In this study, an integration of geophysical survey methods including Vertical Electrical Sounding (VES), ground geo-magnetic methods and soil-samples texture analysis were performed at selected suggested water harvesting sites in the Northern Jordanian Badia to investigate and characterize the shallow subsurface stratigraphic sequences and structures. The preliminary results of geoelectrical investigations provided general picture about the nature of subsurface stratigraphical sequences at each surveyed site. Moreover, the results of ground geo-magnetic investigations indicated to the presence of near-surface subsurface faults that could play a negative role for establishing water harvesting dams at Al-Subhi-1 site and to a lesser extent at Al-Ghulaisi site. The soil textural analysis of Al-Subhi-1 site was found to be of a loamy sand type, whereas the other five sites were found to be of a clayey loam type. However, further high resolution geophysical techniques including the use of low-frequency Ground Penetration Radar (GPR) and 2D-Electrical Resistivity Tomography (ERT) are recommended to conclusively decide if these sites are suitable or not for water harvesting