H.T. Abdel Hamid; W. Wenlong; L. Qiaomin
Abstract
Flash flood has been increasing in the Khartoum area, Sudan due to geographical conditions and climatic change as heavy rainfall and high temperature, therefore the present work tried to estimate the sensitivity of flash flood. The present work proposes an advanced technique of flood sensitivity mapping ...
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Flash flood has been increasing in the Khartoum area, Sudan due to geographical conditions and climatic change as heavy rainfall and high temperature, therefore the present work tried to estimate the sensitivity of flash flood. The present work proposes an advanced technique of flood sensitivity mapping using the method of analytical hierarchy process. Ten factors as elevation, slope, distance from the network, land use, density of the drainage, flow accumulation, surface roughness, stream power index, topographic wetness index and curvature of the topography were digitized and then contributed in the mapping of Flash flood. Remote sensing data were integrated with analytical hierarchy process to determine the flood sensitive area in Sudan. The model was applied and completed as the consistency ratio was mostly reasonable (< 0.1). Based on the proposed model, about 75.56 Km2 (12.26 %), 156.14 Km2 (25.33%), 169.89 Km2 (27.56 %), 141.40 Km2 (22.94 %) and 73.50 Km2 (11.92 %); were classified as no susceptible, low susceptible, high susceptible, moderate susceptible and very highly susceptible to flooding. The present study showed a high variation in flood sensitivity due to climatic change and geographic condition. This index can be modified and applied in areas of the same characteristics of climatic conditions as one of the main recommendation in the study area. The study showed that poor infrastructure and lack of preparedness were the main causes of the disaster of flood in Sudan. This study merely demonstrated the critical analysis of geospatial mapping in proper mitigating, sustainable development and great monitoring the negative effects of flooding along the Khartoum region to reduce hazards of flood.
Environmental Management
J.L. Ogania; G.R. Puno; M.B.T. Alivio; J.M.G. Taylaran
Abstract
Flooding is one of the most devastating natural disasters occurring annually in the Philippines. A call for a solution for this malady is very challenging as well as crucial to be addressed. Mapping flood hazard is an effective tool in determining the extent and depth of floods associated with hazard ...
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Flooding is one of the most devastating natural disasters occurring annually in the Philippines. A call for a solution for this malady is very challenging as well as crucial to be addressed. Mapping flood hazard is an effective tool in determining the extent and depth of floods associated with hazard level in specified areas that need to be prioritized during flood occurrences. Precedent to the production of maps is the utilization of reliable and accurate topographic data. In the present study, the performance of 3 digital elevation models having different resolution was evaluated with the aid of flood modeling software such as hydrologic engineering centre-hydrologic modeling system and hydrologic engineering centre-river analysis system. The two-dimensional models were processed using three different digital elevation models, captured through light detection and ranging, interferometric synthetic aperture radar, and synthetic aperture radar technologies, to simulate and compare the flood inundation of 5-, 25- 100-year return periods. The accuracy of the generated flood maps was carried out using statistical analysis tools - Overall accuracy, F-measure and root-mean-square-error. Results reveal that using light detection and ranging–digital elevation model, the overall accuracy of the flood map is 82.5% with a fitness of 0.5333 to ground-truth data and an error of 0.32 meter in simulating flood depth which implies a promising performance of the model compared to other data sources. Thus, higher resolution digital elevation model generates more accurate flood hazard maps while coarser resolution over-predicts the flood extent.
