Steven E. Yochum, Tyler Wible, Matthew Korsa
et al.
AbstractThe Flood Potential Portal (https://floodpotential.erams.com/) has been developed for the contiguous United States, as a practitioner‐focused tool that uses observational data (streamgages) to enhance understanding of how floods vary in space and time, and assist users in making more informed peak discharge predictions for infrastructure design and floodplain management. This capability is presented through several modules. The Mapping module provides tools to explore variability using multiple indices, and provides detailed information, figures, and algorithms describing and comparing flooding characteristics. The Cross‐Section Analysis module allows users to cut regional‐scale sections to interpret the role of topography in driving flood variability. The Watershed Analysis module provides multiple methods for quantifying expected peak discharge magnitudes and flood frequency relationships at user‐selected locations, including the integration of observed trends in flood magnitudes due to climate change and other sources of nonstationarity into decision making. The Streamgage Analysis module performs streamgage flood‐frequency analyses. These modules are based in part on the flood potential method, through the use of 207 zones of similar flood response defined using more than 8200 streamgages with watershed areas <10,000 km2. Regression models that define each zone had high explained variance (average R2 = 0.93). An example is provided to illustrate use of the Flood Potential Portal for the design of a hypothetical bridge replacement.
AbstractThe valley plain has the characteristics of both mountainous hills and plains, with special terrain conditions and frequent floods. In order to improve the drainage capacity of the river valley plain, this article takes the Bihu Plain in the Oujiang River Basin as an example, uses MIKE11 one-dimensional hydrodynamic software to establish a mathematical model of the river network, analyzed the flood and drainage in the river valley plain, studied the impact of Traditional Flood control mode and Flood control mode based on sponge cities concept in regional drainage, analyzes the advantages and disadvantages of different flood control strategies in practical cases, and provides solutions for regional flood control, Summarized and clarified the relationship between urban flood control and watershed flood control.
AbstractFacing climate change and rapid urbanization, urban flooding has exposed human and properties to increasing disaster risks. The attention from researchers and decision‐makers to understand the key role of flood regulation service (FRS) in flood management has arisen. However, the mechanism of FRS supply–demand is little known from landscape scale. The FRS assessment methodology considering interacts between source, sink, and flow landscape was proposed in this study. The spatial distributions of surface runoff generation, runoff reduction capacity, and flood inundation were mapped using one‐dimensional rainfall–runoff method SCS‐CN and two‐dimensional flood propagation model CADDIES. Four 3‐hour designed rainfall scenarios ranging from nuisance to extreme events (3a, 11a, 56a, and 100a) were simulated. The Liuyang River Watershed in Changsha Municipality, China was selected for case study. The results showed that, the differences of runoff reduction coefficient and runoff generation volume between vegetation and built‐up landscape have shortened. The peak flood depth, extent of flood inundation, and peak flood velocity have increased continuously with the growing rainfall intensity. The number of source–sink mismatch catchment was the highest under 56 and 100a, and the most of source‐sink match catchments were observed under 3a. Under four rainfall scenarios, the changes of source–sink relationships were witnessed and the potentials of flow zone in source–sink mismatch catchments have increased. The FRS management framework concerning supply–demand connections has been proposed based on source–sink–flow analysis. These findings could provide a scientific basis for sustainable urban flood management and disaster risk mitigation.
AbstractRiver floods in Norway have proven devastating for communities and individuals for centuries. Although usually incurring few flood fatalities, the Norwegian population is still vulnerable to river floods in that important infrastructure and other economic assets are located in flood zones. In trying to explain this vulnerability, this paper applies the Pressure and Release model. Two main root causes are identified: Norway's political and economic systems. The political system creates dynamic pressures in terms of governance issues permitting decision making that increases river flood vulnerability. The economic system creates a different dynamic pressure through the insurance system that leaves Norwegian municipalities with few economic incentives to leave flood zones undeveloped.