Floods are a natural hazard that affect communities worldwide, but to date the vast majority of flood hazard research and mapping has been undertaken by wealthy developed nations. As populations and economies have grown across the developing world, so too has demand from governments, businesses, and NGOs for modeled flood hazard data in these data-scarce regions. We identify six key challenges faced when developing a flood hazard model that can be applied globally and present a framework methodology that leverages recent cross-disciplinary advances to tackle each challenge. The model produces return period flood hazard maps at ∼90 m resolution for the whole terrestrial land surface between 56°S and 60°N, and results are validated against high-resolution government flood hazard data sets from the UK and Canada. The global model is shown to capture between two thirds and three quarters of the area determined to be at risk in the benchmark data without generating excessive false positive predictions. When aggregated to ∼1 km, mean absolute error in flooded fraction falls to ∼5%. The full complexity global model contains an automatically parameterized subgrid channel network, and comparison to both a simplified 2-D only variant and an independently developed pan-European model shows the explicit inclusion of channels to be a critical contributor to improved model performance. While careful processing of existing global terrain data sets enables reasonable model performance in urban areas, adoption of forthcoming next-generation global terrain data sets will offer the best prospect for a step-change improvement in model performance.

/pdf/a-high-resolution-global-flood-hazard-model-4jdmmflnxn.pdf

A high‐resolution global flood hazard model

Risk-based methodology for scour analysis at bridge foundations

A dam is a structure constructed across river which stores water and supplies water for various purposes. Though the dams have many benefits, there is always a threat of dam break floods which are devastating in nature. Hence it becomes essential to analyze and simulate dam failure scenarios to understand the severity of dam break flood and identify areas under threat which helps in land use planning and developing emergency response plans. This study attempts to carry out dam break/breach analysis for the Hidkal dam using a one-dimensional hydraulic model called Hydraulic Engineering Centre's River Analysis System (HEC-RAS). HEC-GeoRAS tool is used to extract river geometry data from the Cartosat-1 digital elevation model (DEM) and to generate the inundation map to identify the areas affected. The study involves the prediction of breach parameters, breach flood hydrograph, peak flow, flood arrival time, and generation of inundation maps. The dam break model is simulated for unsteady flow conditions using Probable Maximum Flood (PMF) corresponding to piping and overtopping failure scenarios. HEC-RAS tool is utilized to determine the breach outflow hydrograph and hydraulic conditions at critical downstream locations. Further, the breach outflow hydrographs are routed using dynamic flood wave routing. Further HEC-RAS model is simulated for breach parameters derived from five different empirical methods, and the results are compared. A sensitivity analysis is also carried out to know the variation of peak flow and maximum stage with respect to the breach parameters. The immediate downstream of the dam experience a peak flow of 72,085.45 m3/s and 78,454.82 m3/s and the corresponding inundation area of 75.224 km2 and 79.205 km2 due to piping failure and overtopping failure respectively. Around twenty village located on the downstream of dam location gets affected due to flood produced by dam break. The analysis shows that overtopping failure is more severe than failure due to piping. The study shall further help authorities concerned to develop an emergency response plan and flood mitigation measures.

Dam break analysis using HEC-RAS and HEC-GeoRAS: A case study of Hidkal dam, Karnataka state, India

The need of addressing “residual flood risk” associated with structural protection measures, such as levee systems and flood-control reservoirs, has fostered actions aimed at increasing flood risk awareness. Structural measures have lowered risk perception by inducing a false sense of safety. As a result, these structures contribute to an underestimation of the “residual risk”. We analyze the effect of different reservoir operations, such as coping with drought versus coping with flood events, on flood inundation patterns. First, a hydrological model simulates different scenarios, which represent the dam regulation strategies. Each regulation strategy is the combination of an opening of the outlet gate and of the initial water level in the reservoir. Second, the corresponding outputs of the dam in terms of maximum discharge values are estimated. Then, in turn, each output of the dam is used as an upstream boundary condition of a hydraulic model used to simulate the flood propagation and the inundation processes in the river reach. The hydraulic model is thus used to determine the effect, in terms of inundated areas, of each dam regulation scenario. Finally, the ensemble of all flood inundation maps is built to define the areas more prone to be flooded. The test site is the Casanuova dam (Umbria, central Italy) which aims at: (i) mitigating floods occurring at the Chiascio River, one of the main tributaries of Tiber River, while (ii) providing water supply for irrigation. Because of these two competitive interests, the understanding of different scenarios generated by the dam operations offers an unique support to flood mitigation strategies. Results can lead to draw interesting remarks for a wide number of case studies.

Coping with Extreme Events: Effect of Different Reservoir Operation Strategies on Flood Inundation Maps

Experimental study and numerical verification of silted-up dam break

The U.S. Army Corp of Engineers, in conjunction with the State of Hawaii, is evaluating the risks associated with potential failures of 11 Hawaii dams. An important question to be answered in any Dam safety study is What will happen if the dam fails? This question can be answered through the use of hydrologic and hydraulic computer models. The Hawaii Dam Break studies were performed by a team of federal, state, and consulting engineers. Very early in this study, it was decided that a consistent methodology would need to be used for all of the Dam Break analyses performed by the team. Part of the methodology was to use a specific set of computer models to perform the analyses. A Dam Break study consists of precipitation analyses; hydrologic modeling; dam breaching analysis; dam break floodwave routing; and inundation mapping of the resultant flood. Precipitation analyses were performed by utilizing Technical Paper Number 43, Rainfall-Frequency Atlas of the Hawaiian Islands (NOAA, 1963); Rainfall Frequency study for Oahu (Giambelluca et al., 1984); and Hydro-Meteorological Report 39, Probable Maximum Precipitation in the Hawaiian Islands (NOAA, 1963), in conjunction with several GIS tools and techniques. Hydrologic modeling was performed with the HEC-HMS (Hydrologic Modeling System) software. Dam breaching analysis and routing of the resulting flood wave was performed with the HEC-RAS (River Analysis System) software. In areas where one-dimensional river hydraulics models were thought to be potentially inadequate, the two-dimensional model FLOW-2D was used for comparison of results. Inundation mapping of the resulting floods from various dam break scenarios was performed with the HEC-GeoRAS software, an ArcGIS extension that processes HEC-RAS model results. This paper discusses the use of HEC-HMS, HEC-GeoHMS, HEC-RAS, HEC-GeoRAS, and FLOW-2D for performing the hydrology, hydraulics, and inundation mapping required for performing a dam break analysis.

Hydrologic and Hydraulic Models for Performing Dam Break Studies

The use of geospatial data for the development of hydraulic models and mapping of simulation results has become standard practice for floodplain evaluation. As the use for geospatial data has grown, reliance on a GIS to store, process, and visualize data has increasingly placed requirements on the hydraulic engineer to develop GIS proficiency. GIS proficiency has resulted in even more complex datasets being provided to the hydraulic engineer, requiring additional GIS expertise to manage and process data suitable for hydraulic analysis. Geospatial capabilities have been added to the Hydrologic Engineering Center's River Analysis System (HEC-RAS) to allow the hydraulic engineer to more efficiently develop hydraulic models through visualization of model results and refinement of model geometry within a consistent modeling environment.

Geospatial capabilities of hec-ras for model development and mapping

New Floodplain Delineation Capabilities in HEC-RAS

The Santa Barbara post-wildfire debris flows and the Brumadinho tailing-dam failure were two of the most catastrophic flood events of the late 2010s. Both these events carried so much solid-phase material, that classic, clear-water, flood risk approaches cannot replicate them, or forecast other events like them. This case study applied the new non-Newtonian features in HEC-RAS 6.1 to these two events, testing the most widely used flood risk model on the two most common mud and debris flow hazards (post-wildfire floods and mine tailing dam failures). HEC-RAS reproduced the inundation boundaries and the event timing (where available) for both events. The ratio between the largest debris flow clasts and the channel size, parametric trade-offs, the “convex” alluvial plain topography, and the stochasticity introduced by urban infrastructure made the Santa Barbara modeling more difficult and less precise than Brumadinho. Despite these challenges, the results provide prototype scale validation and verification of these new tools in this widely applied flood risk model.

/pdf/prototype-scale-evaluation-of-non-newtonian-algorithms-in-ism0y0sr.pdf

Prototype Scale Evaluation of Non-Newtonian Algorithms in HEC-RAS: Mud and Debris Flow Case Studies of Santa Barbara and Brumadinho

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Cameron T. Ackerman

Author Tools

Chat about Author

Papers

Hydrologic and Hydraulic Models for Performing Dam Break Studies

Geospatial capabilities of hec-ras for model development and mapping

New Floodplain Delineation Capabilities in HEC-RAS

Prototype Scale Evaluation of Non-Newtonian Algorithms in HEC-RAS: Mud and Debris Flow Case Studies of Santa Barbara and Brumadinho