Flood studies include detailed engineering reports and flood maps. The engineering reports are typically technical in nature and document the data, assumptions, and results of the hydrologic and hydraulic analyses required to create flood maps. Flood maps are created by combining hydraulic model results for different sized floods with high-accuracy ground information. Flood maps identify where water will flow during a flood, and what land could be flooded during different sized floods. Most flood maps focus on floods caused by high river flows when water escapes the river channel, most often experienced in spring or following summer rainstorms, but they can also show areas at risk from ice jam floods or document the extent of historic floods.Flood inundation maps show areas at risk for different sized floods, including ice jam floods in some communities, and identify areas protected by flood berms. Because they map a wide range of floods, they are most often used for emergency response planning and to inform local infrastructure design. Flood hazard maps define floodway and flood fringe areas for the 1:100 design flood and are typically used by communities for planning or to help make local land use and development decisions. The floodway is the portion of the flood hazard area where flows are deepest, fastest and most destructive. The flood fringe is the portion of the flood hazard area outside of the floodway, where flood water is generally shallower and flows slower than in the floodway. High hazard flood fringe is the area within the flood fringe with deeper or faster moving water than the rest of the flood fringe. Protected flood fringe identifies areas that could be flooded if dedicated flood berms fail or do not work as designed during the 1:100 design flood. Flood hazard maps define floodway and flood fringe areas for the 1:100 design flood and are typically used by communities for planning or to help make local land use and development decisions. Flood hazard maps can also illustrate additional information for communities to consider, including incremental areas at risk for floods larger than the 1:100 design flood, such as the 1:200 and 1:500 floods.Visit www.floodhazard.alberta.ca for more information about the Flood Hazard Identification Program. The website includes different sections for final flood studies and for draft flood studies. Flood maps can be viewed directly using the Flood Awareness Map Application at https://floods.alberta.ca/. The Alberta Flood Mapping GIS dataset is updated when new information is available or existing information changes. therefore, the Government of Alberta assumes no responsibility for discrepancies at the time of use. Users should check https://geodiscover.alberta.ca/ to verify they have the most recent version of the Alberta Flood Mapping GIS dataset.

Torrential and long-lasting rainfall often causes long-duration floods in flat and lowland areas in data-scarce Nyaungdon Area of Myanmar, imposing large threats to local people and their livelihoods. As historical hydrological observations and surveys on the impact of floods are very limited, flood hazard assessment and mapping are still lacked in this region, making it hard to design and implement effective flood protection measures. This study mainly focuses on evaluating the predicative capability of a 2D coupled hydrology-inundation model, namely the Rainfall-Runoff-Inundation (RRI) model, using ground observations and satellite remote sensing, and applying the RRI model to produce a flood hazard map for hazard assessment in Nyaungdon Area. Topography, land cover, and precipitation are used to drive the RRI model to simulate the spatial extent of flooding. Satellite images from Moderate Resolution Imaging Spectroradiometer (MODIS) and the Phased Array type L-band Synthetic Aperture Radar-2 onboard Advanced Land Observing Satellite-2 (ALOS-2 ALOS-2/PALSAR-2) are used to validate the modeled potential inundation areas. Model validation through comparisons with the streamflow observations and satellite inundation images shows that the RRI model can realistically capture the flow processes (R2 ≥ 0.87; NSE ≥ 0.60) and associated inundated areas (success index ≥ 0.66) of the historical extreme events. The resultant flood hazard map clearly highlights the areas with high levels of risks and provides a valuable tool for the design and implementation of future flood control and mitigation measures.

These data are supplementary to the journal article Makdisi, A.J., Kramer, S.L. (In-Review). Framework for Mapping Liquefaction Hazard-Targeted Design Ground Motions (doi to be updated on full publication). This dataset includes tabular data summarizing mean and standard deviation liquefaction factor of safety (FSL) ratios, effective FSL return periods, and example reference liquefaction-targeted design peak ground acceleration parameters (PGAL) for 96 geographic locations throughout the conterminous United States. These data were used to generate Figure 4, Figure 5, Figure 7, and Table 2 and Table 5 in the article. Notes: - Procedures for calculating PGAL and FSL are detailed in Section 4.1 (Equations 2 and 3 and Figure 6) of the corresponding journal article. - Mean magnitude Mw was calculated using the procedures outlined in the Appendix (Equation A.4a and A.4b) of the corresponding journal article. - Blank entries in the "SummaryData_Tr*.csv" files should be interpreted as NaN, and correspond to study locations where the computed liquefaction factors of safety (FSL) were above 3.0 for all soil conditions considered (i.e., liquefaction hazard was considered sufficiently low at these sites)

Flood studies include detailed engineering reports and flood maps. The engineering reports are typically technical in nature and document the data, assumptions, and results of the hydrologic and hydraulic analyses required to create flood maps. Flood maps are created by combining hydraulic model results for different sized floods with high-accuracy ground information. Flood maps identify where water will flow during a flood, and what land could be flooded during different sized floods. Most flood maps focus on floods caused by high river flows when water escapes the river channel, most often experienced in spring or following summer rainstorms, but they can also show areas at risk from ice jam floods or document the extent of historic floods. Flood inundation maps show areas at risk for different sized floods, including ice jam floods in some communities, and identify areas protected by flood berms. Because they map a wide range of floods, they are most often used for emergency response planning and to inform local infrastructure design. Flood hazard maps define floodway and flood fringe areas for the 1:100 design flood and are typically used by communities for planning or to help make local land use and development decisions. The floodway is the portion of the flood hazard area where flows are deepest, fastest and most destructive. The flood fringe is the portion of the flood hazard area outside of the floodway, where flood water is generally shallower and flows slower than in the floodway. High hazard flood fringe is the area within the flood fringe with deeper or faster moving water than the rest of the flood fringe. Protected flood fringe identifies areas that could be flooded if dedicated flood berms fail or do not work as designed during the 1:100 design flood. Visit www.floodhazard.alberta.ca for more information about the Flood Hazard Identification Program. The website includes different sections for final flood studies and for draft flood studies. Flood maps can be viewed directly using the Flood Awareness Map Application. The Alberta Flood Mapping GIS dataset is updated when new information is available or existing information changes; therefore, the Government of Alberta assumes no responsibility for discrepancies at the time of use. Users should check https://geodiscover.alberta.ca/ to verify they have the most recent version of the Alberta Flood Mapping GIS dataset.Source: This item was created using the Alberta Flood Hazard Identification Program Mapping geodatabase, you can find the metadata and downloadable .gdb here. Data Vintage: 2024-09-23Update Frequency: as neededContact Information:For inquiries regarding the data please contact Alberta Environment and Protected Areas, Government of Alberta (epa.flood@gov.ab.ca)For inquiries regarding the service, please leave a comment below

This module focuses on teaching the knowledge and technical skills related to flood inundation mapping and its impact on designing resilient and sustainable hydraulic infrastructure. It consists of the following sections:

Section 1: Introduction Section 2: Machine Learning for Flood Inundation Mapping Section 3: Evaluation of Flood Inundation Mapping Section 4: Decision Making for Hydraulic Design

The U.S. National Seismic Hazard Model (NSHM) was updated in 2023 for all 50 states using the best available science related to earthquake seismicity, fault ruptures, ground motions, and hazard estimation techniques to produce a standard of practice for public policy applications. Best available or applicable science is defined here as well-vetted and published hazard input component models and information that are accepted through a comprehensive review process, consistent with open and timely science principles, and encompass a scientifically reasonable range of earthquake characteristics and ground motion effects that improve the basis of the 2023 NSHM. This time-independent probabilistic seismic hazard model benefited from several dozens of co-authors, more than 50 reviewers, and hundreds of end-users, and hazard scientists that attended the public workshops and provided technical inputs and reviews of the inputs and their integration in the hazard assessment. The hazard assessment applies new earthquake catalogs, declustering algorithms, gridded seismicity models, magnitude-scaling equations, fault-based structural and deformation models, multi-fault earthquake rupture forecast models, semi-empirical and simulation-based ground motion models, and site amplification models conditioned on velocities of the upper 30 m of soil and deeper sedimentary structure. Resulting seismic hazard calculations yield hazard curves, maps, uniform hazard response spectra, and disaggregations which are developed for spectral accelerations at 21 oscillator periods, two peak parameters, and eight site classes that are now required by the 2020 NEHRP Recommended Seismic Provisions and applied in multiple other public policy products. A system-level test is performed to ensure the resulting ground motions are consistent with historical intensity information. Several impact products including building seismic design criteria, intensity maps (Modified Mercalli Intensity), ground motion scenarios, and engineering risk assessments that show the potential physical and social impacts and provide a basis for assessing, planning, and mitigating the effects of future earthquakes across the U.S.

The USGS collaborates with organizations (such as the Building Seismic Safety Council) that develop model building and bridge design codes to make seismic design parameter values available to engineers. The design code developers first decide how USGS earthquake hazard information should be applied in design practice. Then the USGS calculates gridded values of seismic design parameters based on USGS hazard values in accordance with design code procedures. The U.S. Seismic Design Maps application provides seismic design parameter values from the following design code editions: 2013 ASCE/SEI 41, 2012/09/06 International Building Code, 2010/05 ASCE/SEI 7 Standard, 2009/03 NEHRP Recommended Seismic Provisions, 2009 AASHTO Guide Specifications for LRFD Seismic Bridge Design. The USGS also provides data files and maps of these gridded design values.

In seismically-active regions such as Greece, the mapping of active faults is a key step to assess seismic hazards and evaluate deterministic ground motion scenarios for infrastructure works, pipeline designs and other constructions of critical importance. Here, we present a comprehensive database of active onshore and offshore faults in Greece based on existing studies and GIS geospatial mapping using geological, geophysical, seismological and geomorphological criteria. The design and population of the database follows the NOAFaults concept http://doi.org/10.5281/zenodo.3483136 and development in ARCGIS environment. The HELPOS database includes over 550 faults with simplified (linear) traces and lengths between 8 – 108 km (onshore part) together with their corresponding 2D rupture planes. Additional information includes parametric data such as maximum expected magnitude, slip rate, length, width, strike, dip angle, last seismic event, rupture depth (to top-fault) and fault kinematics. A particular aim of the HELPOS Fault database has been an update of the seismic sources model for the seismic hazard assessment of Greece considering shallow earthquakes, which involves modeling surface fault traces in terms of seismic sources at depth. The fault database is a major contribution to HELPOS with applications among others in volcano-tectonic settings, urban planning, paleoseismology, landscape processes, and in the study of active tectonics, deformation and interactions between overriding plate (Aegean) faults and the Hellenic subduction.

In this version of the database (v1.8) we include the onshore fault traces and rupture planes and the offshore fault traces.

We acknowledge funding by project "HELPOS - Hellenic Plate Observing System” (MIS 5002697) which was funded by the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund).

Digital Q3 Flood Data are developed by scanning the existing FIRM hardcopy, vectorizing a thematic overlay of flood risks. Vector Q3 Flood Data files contain only certain features from the existing FIRM hardcopy. Q3 vector data are contained in one single countywide file, including all incorporated and unincorporated areas of a county.

 Digital Q3 Flood Data do not replace the existing FIRM hardcopy or, if one
 exists, DFIRM product. The product is designed to support planning activities,
 some Community Rating System activities, insurance marketing, and mortgage
 portfolio reviews. It does not provide base flood elevation information; thus,
 it has limited application for engineering analysis, particularly for site
 design or rating flood insurance policies for properties located within Special
 Flood Hazard Areas (SFHAs).

 Digital Q3 Flood Data are not tied to a base map, are not used to produce a new
 version of the FIRM hardcopy, and are not subjected to community review. The
 digital Q3 Flood Data are designed to provide guidance and a general proximity
 of the location of Special Flood Hazard Areas.

 The digital Q3 Flood Data product can be a valuable tool in screening property
 addresses within a Geographic Information System to determine flood risks.
 However, since the geographic processing performed to develop digital Q3 Flood
 Data may introduce differences with the FIRM hardcopy source, users must apply
 considerable care and judgment in the application of this product. For
 instance, digital Q3 Flood Data may be overlaid on highly detailed large-scale
 community base mapping data, but, if parcel level determinations are made, they
 must be prefaced with information about the accuracy of the data from which
 they are derived.

 Contents of Q3 Data

 The vectorized features contained in digital Q3 Flood Data files include:

 - Annual chance floodplain areas of 1 and 0.2 percent, including Zone V areas,
 certain floodway areas, and zone designations
 - Political areas, including community identification numbers
 - FIRM panel areas, including panel number and suffix
 - 7.5-minute quadrangle areas
 - Mapable Letters of Map Change (LOMCs)

 [Summary provided by FEMA]

Flood studies include detailed engineering reports and flood maps. The engineering reports are typically technical in nature and document the data, assumptions, and results of the hydrologic and hydraulic analyses required to create flood maps. Flood maps are created by combining hydraulic model results for different sized floods with high-accuracy ground information. Flood maps identify where water will flow during a flood, and what land could be flooded during different sized floods. Most flood maps focus on floods caused by high river flows when water escapes the river channel, most often experienced in spring or following summer rainstorms, but they can also show areas at risk from ice jam floods or document the extent of historic floods. Flood inundation maps show areas at risk for different sized floods, including ice jam floods in some communities, and identify areas protected by flood berms. Because they map a wide range of floods, they are most often used for emergency response planning and to inform local infrastructure design. Flood hazard maps define floodway and flood fringe areas for the 1:100 design flood and are typically used by communities for planning or to help make local land use and development decisions. The floodway is the portion of the flood hazard area where flows are deepest, fastest and most destructive. The flood fringe is the portion of the flood hazard area outside of the floodway, where flood water is generally shallower and flows slower than in the floodway. High hazard flood fringe is the area within the flood fringe with deeper or faster moving water than the rest of the flood fringe. Protected flood fringe identifies areas that could be flooded if dedicated flood berms fail or do not work as designed during the 1:100 design flood. Visit www.floodhazard.alberta.ca for more information about the Flood Hazard Identification Program. The website includes different sections for final flood studies and for draft flood studies. Flood maps can be viewed directly using the Flood Awareness Map Application. The Alberta Flood Mapping GIS dataset is updated when new information is available or existing information changes; therefore, the Government of Alberta assumes no responsibility for discrepancies at the time of use. Users should check https://geodiscover.alberta.ca/ to verify they have the most recent version of the Alberta Flood Mapping GIS dataset.Source: This item was created using the Alberta Flood Hazard Identification Program Mapping geodatabase, you can find the metadata and downloadable .gdb here. Data Vintage: 2024-09-23Update Frequency: as neededContact Information:For inquiries regarding the data please contact Alberta Environment and Protected Areas, Government of Alberta (epa.flood@gov.ab.ca)For inquiries regarding the service, please leave a comment below

Area exposed to one or more hazards represented on the hazard map used for flood risk analysis. The hazard map is the result of hydraulic modelling carried out in 2018 by the hydratec design office, whose objective was to assess the intensity of the hazard at any point in the study area. The assessment method led to the delimitation of a set of areas on the study perimeter, constituting a graduated zoning based on the level of water heights of the hazard. The assignment of a hazard level at a given point in the territory takes into account the probability of occurrence of the dangerous phenomenon (the centennial flood) and the natural terrain of the area. All hazard areas shown on the hazard map are included. Areas protected by protective structures are represented (possibly in a specific way) because they are always considered subject to hazard (case of breakage or inadequacy of the structure), here we speak of hydraulic transparency. Hazard zones can be described as developed data to the extent that they result from a synthesis using multiple sources of calculated, modelled or observed hazard data. These source data are not concerned by this class of objects but by another standard dealing with the knowledge of hazards. Some areas of the study area are considered “zero, insignificant or white zones”. These are the areas where the hazard has been studied and is nil. These areas are not included in the object class and do not have to be represented as hazard zones.

Probabilistic earthquake hazard maps were prepared for the Fiji Islands. Damage has been caused by Fiji earthquakes around 1850, in 1884, 1902, 1919, 1932 (twice), 1953 and 1979. No previous …Show full descriptionProbabilistic earthquake hazard maps were prepared for the Fiji Islands. Damage has been caused by Fiji earthquakes around 1850, in 1884, 1902, 1919, 1932 (twice), 1953 and 1979. No previous assessment had produced a comprehensive description of the earthquake hazard in Fiji and the present study was initiated in 1990 when the author was attached to the Mineral Resources Department, Fiji. Collection and analysis of data continued at MRD until 1992 and the study was completed at the Australian Geological Survey Organisation in 1993-1997. The aim of the study was to produce probabilistic earthquake hazard maps which can be used in the National Building Code for Fiji, for design of special structures, for planning, for emergency management and for risk management. Few, if any, similar studies have been undertaken in the seismically active Southwest Pacific.

Abstract: This data shows the extent of land that might be flooded by the sea (coastal flooding) and the associated flood depths during a theoretical or ‘design’ flood event with an estimated probability of occurrence, rather than information for actual floods that have occurred in the past. This represents the worst case scenario as any flood defences potentially protecting the coastal floodplain are not taken into account. Flood event probabilities are referred to in terms of a percentage Annual Exceedance Probability, or ‘AEP’. This represents the probability of an event of this, or greater, severity occurring in any given year. These probabilities may also be expressed as the chance or odds (e.g. 200 to 1) of the event occurring in any given year. They are also commonly referred to in terms of a return period (e.g. the 200-year flood), although this period is not the length of time that will elapse between two such events occurring, as, although unlikely, two very severe events may occur within a short space of time. The following sets out the range of flood event probabilities for which coastal flood extent maps were developed, expressed in terms of Annual Exceedance Probability (AEP), and identifies their parallels under other forms of expression. 50% AEP can also be expressed as the 2 Year Return Period and as the 2:1 odds of occurrence in any given year. 20% AEP can also be expressed as the 5 Year Return Period and as the 5:1 odds of occurrence in any given year. 10% AEP can also be expressed as the 10 Year Return Period and as the 10:1 odds of occurrence in any given year. 5% AEP can also be expressed as the 20 Year Return Period and as the 20:1 odds of occurrence in any given year. 2% AEP can also be expressed as the 50 Year Return Period and as the 50:1 odds of occurrence in any given year. 1% AEP can also be expressed as the 100 Year Return Period and as the 100:1 odds of occurrence in any given year. 0.5% AEP can also be expressed as the 200 Year Return Period and as the 200:1 odds of occurrence in any given year. 0.1% AEP can also be expressed as the 1000 Year Return Period and as the 1000:1 odds of occurrence in any given year. The High End Future Scenario (HEFS) maps represent a projected future scenario for the end of century (circa 2100) and include allowances for projected future changes in sea levels and glacial isostatic adjustment (GIA). The maps include an increase of 1000mm in sea levels above the current scenario estimations. An allowance of -0.5mm/year for GIA was included for the southern part of the national coastline only (Dublin to Galway and south of this). Flooding from other sources may occur and areas that are not shown as being within a flood extent may therefore be at risk of flooding from other sources. The flood extent and depth maps are suitable for the assessment of flood risk at a strategic scale only, and should not be used to assess the flood hazard and risk associated with individual properties or point locations, or to replace a detailed flood risk assessment. Lineage: The National Coastal Flood Hazard Maps (NCFHM) 2021 are ‘predictive’ flood maps, as they provide predicted flood extent and depth information for a ‘design’ flood event that has an estimated probability of occurrence (e.g. the 0.5% AEP event), rather than information for floods that have occurred in the past. The maps have been produced at a strategic level to provide an overview of coastal flood hazard in Ireland, and minor or local features may not have been included in their preparation. A Digital Terrain Model (DTM) was used to generate the maps, which is a ‘bare-earth’ model of the ground surface with the digital removal of human-made and natural landscape features such as vegetation, buildings and bridges. This methodology can result in some of these human-made features, such as bridges and embankments, being shown within a flood extent, when in reality they do not flood. It should be noted that the flood extent maps indicate the predicted maximum extent of flooding, and flooding in some areas, such as near the edge of the floodplain area, might be very shallow. The predicted depth of flooding at a given location is indicated on the flood depth maps. The flood depth is displayed as a constant depth over grid squares with a 5m resolution, whereas in reality depths may vary within a given grid square. No post-processing of the flood extent and depth map datasets has been undertaken to remove small areas of flooding that are remote and isolated, small islands within the flooded area, etc. Local factors such as flood defence schemes, structures in or around river channels (e.g. bridges), buildings and other local influences, which might affect coastal flooding, have not been accounted for. Detailed explanations of the methods of derivation, data used, etc. is provided in the NCFHM 2021 Flood Mapping Methodology Report. Users of the maps should familiarise themselves fully with the contents of this report in advance of the use of the maps. Purpose: The data has been developed to inform a national assessment of flood risk that in turn will inform a review of the Preliminary Flood Risk Assessment required to comply with the requirements of the European Communities (Assessment and Management of Flood Risks) Regulations 2010 to 2015 (the “Regulations”) (implementing Directive 2007/60/EC) for the purposes of establishing a framework for the assessment and management of flood risks, aiming at the reduction of adverse consequences for human health, the environment, cultural heritage and economic activity associated with floods. .hidden { display: none }

Tasmanian Strategic Flood Map (TSFM) Design Flood Event (DFE) outputs. These outputs represent the simulated peak flood water elevation in metres (mAHD) above the Australian Heigth Datum 1983 (AHD-TAS83) for a series of Design Flood Events (2%, 1%, 0.5% and 1% AEP Climate Change). This data is a composite data set of model outputs from twenty-five (25) separate hydrodynamic models. The data provides coverage for all of Tasmania excluding King Island, the Gordon - Franklin basin, Furneaux Islands, and Macquarie Island. Mapping should be interpreted using hydrology and hydrodynamic methodology reports, and relevant catchment level methodology reports on the State Emergency Service Website: https://www.ses.tas.gov.au/floodmaps/tasmanian-flood-mapping-project-reports/. The TSFM offers a strategic view of flood-prone areas under current and future climate conditions and is subject to refinement by respective Local Government Authorities or SES as more refined data becomes available. Decisions on the use of the data should be informed by the supporting technical reports and documentation.

HazMatMapper is an online and interactive geographic visualization tool designed to facilitate exploration of transnational flows of hazardous waste in North America (http://geography.wisc.edu/hazardouswaste/map/). While conventional narratives suggest that wealthier countries such as Canada and the United States (US) export waste to poorer countries like Mexico, little is known about how waste trading may affect specific sites within any of the three countries. To move beyond anecdotal discussions and national aggregates, we assembled a novel geographic dataset describing transnational hazardous waste shipments from 2007 to 2012 through two Freedom of Information Act requests for documents held by the US Environmental Protection Agency. While not yet detailing all of the transnational hazardous waste trade in North America, HazMatMapper supports multiscale and site-specific visual exploration of US imports of hazardous waste from Canada and Mexico. It thus enables academic researchers, waste regulators, and the general public to generate hypotheses on regional clustering, transnational corporate structuring, and environmental justice concerns, as well as to understand the limitations of existing regulatory data collection itself. Here, we discuss the dataset and design process behind HazMatMapper and demonstrate its utility for understanding the transnational hazardous waste trade.

To access this data:

This data is available for licensing to anyone interested in understanding risks around hazardous dams. To request access, click REQUEST ACCESS or email Ken Romano at kromano@ap.org.

Update 2/20/20 This data has been updated with the following: * The dams_in_nid_state_reports.csv file has been updated to include a column for owner_name, as it was provided by the states. Nearly 30,000 dam entries did not have an owner_name provided. Owner names may need deduplication, due to alternate name spellings in the data provided. * New findings regarding dams lacking emergency action plans in Southeastern states, in the Findings section.

Overview

The nation’s dams are on average more than a half-century old and, in some cases, weren’t designed to handle the amount of water that could result from the increasingly intense rainstorms of a changing climate. Yet almost no information has been publicly available about the condition of these dams. Since 2002, the U.S. Army Corps of Engineers has redacted inspectors’ condition assessments from its National Inventory of Dams over security concerns; the Corps makes publicly available only the hazard rating of certain dams, which assesses the potential for loss of human life or economic and environmental damage should a dam fail.

The Associated Press has created an exclusive dataset that fills in those information gaps for a subset of dams across the country. It found at least 1,688 high hazard dams that are in poor or unsatisfactory condition, and in places where failure is likely to kill at least one person.

The AP’s analysis is based on data obtained through dozens of state open-records requests, which allowed the AP to compile a dataset that contains both hazard levels and condition ratings for dams in 45 states and Puerto Rico. Five states – Alabama, Illinois, Maryland, New Jersey and Texas – did not fully comply with the records request for reasons described in the methodology and caveats sections below. (Iowa provided all requested documents but had no dams listed as both high hazard and in poor or unsatisfactory condition).

For the subset of high hazard dams in poor or unsatisfactory condition, the AP is sharing state inspection reports and local emergency action plans that provide additional details about the problems of some particular dams, their potential to inundate nearby areas if they were to catastrophically fail and plans to respond should there be a disaster.

The AP also analyzed the annual budget and staffing levels for dam safety offices in each state using data from an annual survey conducted by the U.S. Army Corps of Engineers.

Additionally, the AP obtained data from the Federal Emergency Management Agency and state dam safety offices about $10 million of federal grants that were awarded this fall to 26 states. The grants are the first under the new Rehabilitation of High Hazard Potential Dams Grant Program. The money is to go toward risk assessments and engineering designs to repair high hazard dams that have failed to meet safety standards and pose an unacceptable risk to the public.

Findings

The AP’s analysis found: * Update 2/20/20: As storms, floods, and dam breaches have hit Mississippi in recent weeks, emergency action plans have been important in denoting whom to contact, who and what has been in danger, and how to handle a dam emergency. An Associated Press analysis of data received in summer 2018 from state and federal agencies found that 111 of the 375 high hazard dams in Mississippi were missing emergency action plans – nearly 30 percent. Some other Southern states had even more dams lacking emergency plans. In North Carolina, 578 of the 1,277 of high hazard dams, nearly half of them, had no emergency plan. In Georgia, 259 of the 623 were missing emergency plans. In fact, in at least seven Southeastern states, at least 20 percent of the high hazard dams were missing emergency plans as of summer 2018. * There are at least 1,688 high hazard dams in poor or unsatisfactory condition in 44 states and Puerto Rico. These potentially dangerous dams account for about 19% of the more than 8,800 high hazard dams for which the AP obtained condition ratings. Iowa listed no high hazard dams as poor or unsatisfactory. * More than half of the dams in the AP’s list of high hazard facilities in poor or unsatisfactory condition are privately owned, which can create challenges for state regulatory agencies seeking to enforce needed repairs or improvements. * About half of the dams in the AP’s list of high hazard facilities in poor or unsatisfactory condition are used primarily for recreation, though that may not have been the purpose for which the dams originally were built. Nearly one-fifth of the dams are used primarily for flood control. * Georgia had 198 high hazard dams in poor or unsatisfactory condition, the highest number among all states for which the AP obtained data. North Carolina was second with 168 such dams, followed by Pennsylvania with 145, Mississippi with 132, Ohio with 124 and South Carolina with 109. * As of summer 2018, more than a quarter of the high hazard dams in poor or unsatisfactory condition had inspection reports that were more than 1.5 years out of date, and about 35% didn’t have emergency action plans documenting procedures in case of the dam’s failure. Note that some of those dams could have undergone inspections or adopted emergency plans since then. * Budget and staffing levels for state dam safety offices declined following the Great Recession and have generally risen since then. California, which has the nation’s largest dam safety program, boosted its budget from around $13 million in 2017 to $20 million this past year and increased its full-time staff positions from 63 to 77 following the failure of the Oroville dam spillway in 2017. * Thirteen states and Puerto Rico were spending less on dam safety programs in their 2019 fiscal years than they did in 2011, and 11 states had fewer full-time positions in their programs as of last year. Alabama is the only state with no dam safety program. * States often have small dam safety staffs to oversee large numbers of dams. Indiana is representative of many states, with a $500,000 budget and six full-time staff positions for a dam safety office that regulates 840 dams.

Localization ideas

The AP’s database of dam inspection records collected from state agencies can be filtered to find the high hazard dams in poor or unsatisfactory condition in your state.

That data also provides key details that can be used for further reporting about the facilities, including their names, exact locations, identification numbers, the year they were built and the dates of their most recent inspections and emergency action plans. For many of these dams, the AP also has provided documents detailing their most recent inspection reports and emergency plans. The datasets on state dam safety program budgets and personnel also can be used to examine how a state’s regulatory oversight has changed over time.

Use the entire dams dataset to map all the dams in your state, find out what share of dams in your state are high hazard and in poor or unsatisfactory condition, and to do further analysis on ownership and purpose.

Some questions to ask:

Are there nearby dams in poor condition that could cause widespread damage if they failed? * Emergency action plans include potential inundation zones if a high hazard dam were to fail. For example, one community potentially in harm’s way is Norwood, Massachusetts, a Boston suburb of nearly 30,000 people. The high hazard dam on nearby Willett Pond is rated in poor condition, primarily because its spillway is capable of handling only about 13% of the water flow from a serious flood, according to a recent inspection report. More than 1,300 properties with structures lie within the dam’s potential inundation zone, including several shopping centers, at least two elementary schools, more than 70 roads and two railroads.

Are there high hazard dams for which there are concerns about whether the structure could withstand a natural disaster? * One example of this is in Alaska, which has five high hazard dams in poor or unsatisfactory condition. Several inspections raised concerns about seismic activity. Inspection reports for the Lower and Upper Wrangell dams note that neither dam “is found to be stable during a seismic event.”

Are there dams with outdated or missing emergency action plans? * One example of this is in New Mexico, where many dams had no emergency action plans as of summer 2018. Many dams there also were rated poor because authorities had no design plans for them. In addition, inspection reports for the majority of the dams mentioned that the dams did not meet standards for a probable maximum precipitation event.

How have state officials responded to previous concerns about the safety of dams? * Following widespread dam failures during intense rainstorms in 2015-2016, South Carolina tripled the personnel in its dam safety program and increased its budget from about $260,000 annually to about $1 million. By contrast, Missouri took no action after a mountaintop reservoir failed in 2005, injuring a park superintendent’s family in the resulting flash flood. Though the governor proposed to significantly expand the number of dams subject to state inspections, the legislation failed to pass.

Interactive

The AP is making an interactive map made in partnership with ESRI for this dataset available early to aid in reporting.

The interactive displays the 1,688 dams in the dataset that are high hazard and in poor or unsatisfactory condition. Coloring is determined by how overdue its last inspection, as of July 2018, is from its expected inspection frequency. By clicking on individual dams, more detailed information from the AP dataset

Cartographic display of cross-scale phenomena and user-centered design are considered through a discussion of the development of an interactive web map depicting local-to-national economic impacts of hurricane storm surge events in Galveston Bay, Texas. Map development and design (as informed by stakeholder focus groups) is described, including approaches to presenting complex, cross-scale impacts of surge events across multiple years and scenarios. Particular consideration is given to how designs may communicate complexity without overly taxing users’ mental and perceptual resources (measured via NASA task-load index) or outstripping their mapping/domain expertise. The map produced uses linked map views to communicate multiple, cross-scale storm surge impacts. The production process and associated user testing highlighted the importance of matching tool complexity to users’ needs and levels of expertise, including through the use of tiered interface design. Optimizing the design of such maps to meet users’ needs is essential to fostering public hazard literacy.

In view of the increasing catchment development and the need to accurately define the flood problem, Lake Macquarie City Council engaged Webb, McKeown & Associates, to undertake a Flood Study. The primary objectives of this Flood Study are: • to define the flood behaviour of the North Creek catchment by producing information on flood levels, velocities and flows for a range of design flood events under existing catchment and floodplain conditions, • to assess the hydraulic categories and undertake provisional flood hazard mapping, • to assess the extent of the flood problem by undertaking a damages assessment, • to formulate suitable hydrologic/hydraulic models that can be used in a subsequent Floodplain Risk Management Study to assess various floodplain management measures, including the effects of further development. This report details the results and findings of the Flood Study investigations. The key elements include: • a summary of available data, • reasons for the choice of hydrologic and hydraulic models, • calibration of these models, • establishment of design flood behaviour, • flood damages assessment. The Flood Study does not consider flooding from local drainage which may result from inadequate urban drainage provisions.

This document presents a new set of earthquake hazard maps for consideration in the next revision of the earthquake loading code AS1170.4 "Structural design actions: Part 4 Earthquake actions in …Show full descriptionThis document presents a new set of earthquake hazard maps for consideration in the next revision of the earthquake loading code AS1170.4 "Structural design actions: Part 4 Earthquake actions in Australia". The earthquake catalogue used here includes events up until 2011. It is a combined version of several catalogues provided by external agencies. This represents the most complete catalogue of earthquakes compiled for Australia. The catalogue is more consistent through conversion of various magnitude measurements into a 'pseudo ML' scale. A systematic logic is used to select preferred magnitude types. Aftershocks, foreshocks and mine blasts have been identified and the declustered catalogue used here is cleaner than any previous Australian catalogue. Earthquake source zones applied in the hazard map use a unique combination of three different layers, which capture seismic characteristics at sub-national, regional and high-activity point scales. The map is one of the first in the world to apply a semi-quantitative measure of Mmax for majority of the source zones in the map. We apply recently developed ground motion prediction equations based on modern methods and data. These equations were used to calculate the ground motion at a range of response spectral accelerations, rather than just calculating the hazard for peak ground acceleration (PGA). A suite of maps is calculated using GA's Earthquake Risk Model (EQRM). The EQRM is open-source, allowing the results to be tested or modified independently. The final 2012 Australian earthquake hazard maps for a range of return periods and response spectral periods are presented herein.

This web map is part of an ASCE Hazard Tool recreation built with ArcGIS Experience Builder, found here, and brings together multiple hazard layers based on ASCE 7-22 standards to support structural design and risk assessment. It includes mapped data for ground snow loads, tornado wind speeds, ice thickness from freezing rain, and wind speeds across various recurrence intervals and risk categories. Snow loads are shown at a 0.5-mile resolution, with elevation limits indicated where applicable. Ice thickness values include concurrent wind and temperature data, while tornado and wind speed layers provide design values for a wide range of building sizes and event frequencies. The original ASCE Hazard Tool can be found here.In addition to these, the map integrates key hazard datasets:ASCE/NOAA_Precip_60min_Tiled (MapServer): Displays 60-minute precipitation values used for flood and drainage design, derived from NOAA data and referenced by ASCE 7-22.Flood Hazard Areas (FEMA FIRM): Shows official flood risk zones from the Federal Emergency Management Agency’s Flood Insurance Rate Map, essential for floodplain management and design in regulated areas.ASCE722/ts2022_Tsunami_Tile (MapServer): Depicts tsunami design zones based on ASCE 7-22 tsunami provisions, identifying coastal areas that require special consideration for tsunami loads.Together, these layers provide a comprehensive overview of environmental hazards for design professionals, enabling better-informed decisions in planning, engineering, and code-compliant construction.