Time Aware is a configurable app template that enables you visualize time enabled layers in a web map using a time slider. This is useful for displaying changes in data over time. Use CasesBuild a stand alone app that presents data changing through time.Build a time aware app and embed it within a story map journal or story map series to include time animation within your story.Configurable OptionsChoose a title, logo, and color scheme.Configure the ability for feature and location search.Customize the color and date time format of the time slider.Enable a legend, scalebar, share dialog, or about window.Supported DevicesThis application is responsively designed to support use in browsers on desktops, mobile phones, and tablets.Data RequirementsThis requires time aware data, to learn more see the configure time help topic. An existing time aware feature service can be consumed from this application, however in order to create your own time aware feature service you will either need ArcGIS Enterprise or an ArcGIS Online subscription.Get Started This application can be created in the following ways:Click the Create a Web App button on this pageShare a map and choose to Create a Web AppOn the Content page, click Create - App - From Template Click the Download button to access the source code. Do this if you want to host the app on your own server and optionally customize it to add features or change styling.

Time-aware layer with multiple collections/flights. Use time filter to view individual dates or disable time in layer options to see all.This layer provides true color aerial imagery developed by the USACE National Coastal Mapping Program (NCMP). The USACE NCMP acquires high-resolution, high-accuracy topographic/bathymetric lidar elevation and imagery on a recurring basis along the sandy shorelines of the US. The program's survey footprint includes an approximately 1-mile wide swath of topography, bathymetry and imagery 500-m onshore and 1000-m offshore. The standard suite of NCMP data products include topographic/bathymetric lidar point clouds, digital surface and elevation models, shoreline vectors and both true-color and hyperspectral imagery mosaics. Value-added derivative information products may include laser reflectance images, landcover classification images and volume change metrics. USACE Headquarters initiated the NCMP in 2004. The program's update cycle follows counter-clockwise along the US West Coast, Gulf Coast, East Coast and Great Lakes approximately every 5 years. Surveys in support of USACE project-specific missions and external partners are included constituent to the current NCMP schedule and reimbursable funding. All work is coordinated with Federal mapping partners through the Interagency Working Group on Ocean and Coastal Mapping (IWGOCM) and the 3D Elevation Program (3DEP).NCMP operations are executed by the Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX). The JALBTCX mission is to perform operations, research and development in airborne lidar bathymetry and complementary technologies to support the coastal mapping and charting requirements of the US Army Corps of Engineers, the US Naval Meteorology and Oceanography Command and the National Oceanic and Atmospheric Administration. Survey operations are conducted worldwide using the Coastal Zone Mapping and Imaging (CZMIL) system and other industry-based coastal mapping and charting systems.

The National Water Model provides forecasts of flow volume and velocity for over 2.7 million stream and river segments in the contiguous United States and is the National Weather Service’s primary tool for predicting river flooding. Two versions of the National Water Model are available in ArcGIS Living Atlas: a short-term model that updates every hour for 18-hrs, and a medium-range model that updates every 6-hrs for a 10-day outlook.This layer provides a summary of the short-term hourly forecast and adds calculated fields such as flow anomaly, maximum anomaly, and the time at maximum flow. It has been filtered to display only areas with positive flow anomalies (i.e., flooding). Leveraging ArcGIS Online hosted feature services, it is ideal for doing spatial and time queries, use in Dashboards, and supporting a variety of custom symbology.By default, this layer is showing time until maximum flow since the short-term model is ideal for providing detailed situational awareness for imminent or occurring events.Companion LayerNational Water Model Maximum Flow (10-Day Forecast)Related LayersNational Water Model (10-Day Forecast)National Water Model (10-Day Anomaly Forecast)National Water Model (Hourly Forecast)National Water Model (Hourly Anomaly Forecast)RevisionsJan 27, 2022: Added 'Forecast Origin' field. Providing the Origin Date/Time of the Forecast Set

FEMA provides access to the National Flood Hazards Layer (NFHL) through web mapping services. The maps depict effective flood hazard information and supporting data. The primary flood hazard classification is indicated in the Flood Hazard Zones layer.The NFHL layers include:Flood hazard zones and labelsRiver Miles MarkersCross-sections and coastal transects and their labelsLetter of Map Revision (LOMR) boundaries and case numbersFlood Insurance Rate Map (FIRM) boundaries, labels and effective datesCoastal Barrier Resources System (CBRS) and Otherwise Protected Area (OPA) unitsCommunity boundaries and namesLeveesHydraulic and flood control structuresProfile and coastal transect baselinesLimit of Moderate Wave Action(LiMWA)Not all effective Flood Insurance Rate Maps (FIRM) have GIS data available. To view a list of available county and single-jurisdiction flood study data in GIS format and check the status of the NFHL GIS services, please visit the NFHL Status Page.Preliminary & Pending National Flood Hazard LayersThe Preliminary and Pending NFHL dataset represents the current pre-effective flood data for the country. These layers are updated as new preliminary and pending data becomes available, and data is removed from these layers as it becomes effective.For more information, please visit FEMA's website.To download map panels or GIS Data, go to: NFHL on FEMA GeoPlatform.Preliminary & Pending DataPreliminary data are for review and guidance purposes only. By viewing preliminary data and maps, the user acknowledges that the information provided is preliminary and subject to change. Preliminary data are not final and are presented in this national layer as the best information available at this time. Additionally, preliminary data cannot be used to rate flood insurance policies or enforce the Federal mandatory purchase requirement. FEMA will remove preliminary data once pending data are available.Pending data are for early awareness of upcoming changes to regulatory flood map information. Until the data becomes effective, when it will appear in FEMA's National Flood Hazard Layer (NFHL), the data should not be used to rate flood insurance policies or enforce the Federal mandatory purchase requirement. FEMA will remove pending data once effective data are available.To better understand Preliminary data please see the View Your Community's Preliminary Flood Hazard Data webpage.FEMA GeoPlatformFEMA's GIS flood map services are available through FEMAs GeoPlatform, an ArcGIS Online portal containing a variety of FEMA-related data.To view the NFHL on the FEMA GeoPlatform go to NFHL on FEMA GeoPlatform.To view the Preliminary and Pending national layers on the FEMA Geoplatform go to FEMA's Preliminary & Pending National Flood Hazard Layer.Technical InformationFlood hazard and supporting data are developed using specifications for horizontal control consistent with 1:12,000–scale mapping. If you plan to display maps from the NFHL with other map data for official purposes, ensure that the other information meets FEMA’s standards for map accuracy.The minimum horizontal positional accuracy for base map hydrographic and transportation features used with the NFHL is the NSSDA radial accuracy of 38 feet. United States Geological Survey (USGS) imagery and map services that meet this standard can be found by visiting the Knowledge Sharing Site (KSS) for Base Map Standards (420). Other base map standards can be found at https://riskmapportal.msc.fema.gov/kss/MapChanges/default.aspx. You will need a username and password to access this information.The NFHL data are from FEMA’s FIRM databases. New data are added continually. The NFHL also contains map changes to FIRM data made by LOMRs.The NFHL is stored in North American Datum of 1983, Geodetic Reference System 80 coordinate system, though many of the NFHL GIS web services support the Web Mercator Sphere projection commonly used in web mapping applications.Organization & DisplayThe NFHL is organized into many data layers. The layers display information at map scales appropriate for the data. A layer indicating the availability of NFHL data is displayed at map scales smaller than 1:250,000, regional overviews at map scales between 1:250,000 and 1:50,000, and detailed flood hazard maps at map scales of 1:50,000 and larger. The "Scalehint" item in the Capabilities file for the Web Map Service encodes the scale range for a layer.In addition, there are non-NFHL datasets provided in the GIS web services, such as information about the availability of flood data and maps, the national map panel scheme, and point locations for LOMA and LOMR-Fs. The LOMA are positioned less accurately than are the NFHL data.Layers in the public NFHL GIS services:Use the numbers shown below when referencing layers by number.0. NFHL Availability1. LOMRs2. LOMAs3. FIRM Panels4. Base Index5. PLSS6. Toplogical Low Confidence Areas7. River Mile Markers8. Datum Conversion Points9. Coastal Gages10. Gages11. Nodes12. High Water Marks13. Station Start Points14. Cross-Sections15. Coastal Transects16. Base Flood Elevations17. Profile Baselines18. Transect Baselines19. Limit of Moderate Wave Action20. Water Lines21. Coastal Barrier Resources System Area22. Political Jurisdictions23. Levees24. General Structures25. Primary Frontal Dunes26. Hydrologic Reaches27. Flood Hazard Boundaries28. Flood Hazard Zones29. Submittal Information30. Alluvial Fans31. Subbasins32. Water Areas

OFFICIALImportant: Our technical support team is available to assist you during business hours only. Please keep in mind that we can only address technical difficulties during these hours. When using the product to make decisions, please take this into consideration.AbstractThis spatial product shows ‘near real-time’ bushfire and prescribed burn extents for all jurisdictions who have the technical ability or appropriate licence conditions to provide this information into a national product.This is a scientific product and should not be used for safety of life decisions. Please refer to jurisdictional emergency response agencies for incident warnings and information.CurrencyDate Created: October 2025Modification Frequency: Every 15 MinutesData ExtentCoordinate Reference: WGS84Spatial ExtentNorth: -9°South: -44°East: 154°West: 112°Source informationPrevious project teams identified source data through jurisdictional websites and the Emergency Management LINK catalogue.Sources for the current iteration of this dataset have been confirmed by each jurisdiction through the EMSINA National and EMSINA Developers networks.This Webservice contains authoritative data sourced from:Australian Capital Territory - Emergency Service Agency (ESA)New South Wales - Rural Fire Service (RFS)Queensland - Queensland Fire and Emergency Service (QFES)South Australia - Country Fire Service (CFS)Tasmania - Tasmania Fire Service (TFS)Victoria – Department of Environment, Land, Water and Planning (DELWP)Western Australia – Department of Fire and Emergency Services (DFES) and Department of Biodiversity, Conservation and Attractions (DBCA)This webservice does not contain data from:Northern Territory – Bushfires NTKnown Limitations:This dataset does not contain information from the Northern Territory Government.This dataset contains a subset of the Queensland bushfire boundary data. The Queensland ‘Operational’ feed that is consumed within this National Database displays the last six (6) months of incident boundaries. In order to make this dataset best represent a ‘near real-time’ or current view of operational bushfire boundaries, Geoscience Australia has filtered the Queensland data to only incorporate the last one (1) week’s data.Geoscience Australia is aware that duplicate data (features) may appear within this dataset. This duplicate data is commonly represented in the regions around state borders where it is operationally necessary for one jurisdiction to understand cross border situations. Care must be taken when summing the values to obtain a total area burnt.The data within this aggregated national product is a spatial representation of the input data received from the custodian agencies. Therefore, data quality and data completion will vary. If you wish to assess more information about specific jurisdictional data and/or data feature(s) it is strongly recommended that you contact the appropriate custodian.The accuracy of the data attributes within this webservice is reliant on each jurisdictional source and the information they elect to publish into their Operational Bushfire Boundary webservices.Attribute Accuracy: The accuracy of the data attributes within this webservice is reliant on each jurisdictional source and the information they elect to publish into their Operational/Going Bushfire Boundary webservices.Data Completeness: The completeness of the data within this webservice is reliant on each jurisdictional source and the information they elect to publish into their Operational/Going Bushfire boundary webservices. In the case of Queensland’s data contribution: Please see the ‘Known Limitations’ section for full details.Schema: The following schema table covers all the core data fields: Note: Geoscience Australia has, where possible, attempted to align the data to the National Current Incident Extent Feeds Data Dictionary. However, this has not been possible in all cases. Geoscience Australia has not included attributes added automatically by spatial software processes in the table below.Lineage statementVersions 1 and 2 (2019/20): This dataset was first built by EMSINA, Geoscience Australia, and Esri Australia staff in early January 2020 in response to the Black Summer Bushfires. The product was aimed at providing a nationally consistent dataset of bushfire boundaries. Version 1 was released publicly on 8 January 2020 through Esri AGOL software.Version 2 of the product was released in mid-February as EMSINA and Geoscience Australia began automating the product. The release of version 2 exhibited a reformatted attributed table to accommodate these new automation scripts.The product was continuously developed by the three entities above until early May 2020 when both the scripts and data were handed over to the National Bushfire Recovery Agency. The EMSINA Group formally ended their technical involvement with this project on June 30, 2020.Version 3 (2020/21): A 2020/21 version of the National Operational Bushfire Boundaries dataset was agreed to by the Australian Government. It continued to extend upon EMSINA’s 2019/20 Version 2 product. This product was owned and managed by the Australian Government Department of Home Affairs, with Geoscience Australia identified as the technical partners responsible for development and delivery.Work on Version 3 began in August 2020 with delivery of this product occurring on 14 September 2020.Version 4 (2021/22): A 2021/22 version of the National Operational Bushfire Boundaries dataset was produced by Geoscience Australia. This product was owned and managed by Geoscience Australia, who provided both development and delivery.Work on Version 4 began in August 2021 with delivery of this product occurring on 1 September 2021. The dataset was discontinued in May 2022 because of insufficient Government funding to sustain the Project.Version 5 (2023/25): A 2023/25 version of the National Near Real-Time Bushfire Boundaries dataset is produced by Geoscience Australia under funding from the National Bushfire Intelligence Capability (NBIC) - CSIRO. NBIC and Geoscience Australia also partnered with the EMSINA Group to assist with accessing and delivering this dataset. This dataset was the first time where the jurisdictional attributes were aligned to AFAC’s draft National Going Bushfire Schema and Data Dictionary.Work on Version 5 began in August 2023 and was released in late 2023 under formal access arrangements with the States and Territories.Version 6 (2025/26) - Current Version A 2025/26 version of the National Near Real-Time Bushfire Extents dataset is produced by Geoscience Australia under project funding from the Department of Climate Change, Energy, the Environment and Water, and the National Emergency Management Agency, with contributions to the National Bushfire Intelligence Capability. This dataset is built directly off Version 5, incorporating improvements from AFAC's finalised National Going Bushfire Schema and Data Dictionary.Work on Version 6 started in September 2025 and was finalised and released in mid-October 2025. This iteration of the dataset is funded until 30 June 2026.Data dictionaryAttribute nameField TypeDescriptionfire_idStringID attached to fire (e.g. incident ID, Event ID, Burn ID).fire_nameStringIncident name. If available.fire_typeStringBinary variable to describe whether a fire was a bushfire or prescribed burn.ignition_dateDateThe date of the ignition of a fire event. Date and time are captured in jurisdiction local time and converted to UTC. Please note when viewed in ArcGIS Online, the date is converted from UTC to your local time.capt_dateDateThe date of the incident boundary was captured or updated. Date and time are captured in jurisdiction local time and converted to UTC. Please note when viewed in ArcGIS Online, the date is converted from UTC to your local time.capt_methodStringCategorical variable to describe the source of data used for defining the spatial extent of the fire.area_haDoubleBurnt area in Hectares. Currently calculated field so that all areas calculations are done in the same map projection. Jurisdiction supply area in appropriate projection to match state incident reporting system.perim_kmDoubleBurnt perimeter in Kilometres. Calculated field so that all areas calculations are done in the same map projection. Jurisdiction preference is that supplied perimeter calculations are used for consistency with jurisdictional reporting.stateStringState custodian of the data. NOTE: Currently some states use and have in their feeds cross border data.agencyStringAgency that is responsible for the incidentdate_retrievedDateThe date and time that Geoscience Australia retrieved this data from the jurisdictions, stored as UTC. Please note when viewed in ArcGIS Online, the date is converted from UTC to your local time.ContactClient Services at Geoscience Australia, clientservices@ga.gov.au

During a search and rescue (SAR) operation, officials don't have time to wait until a GIS specialist is on scene. They need maps immediately. Preconfigured and ready-to-use GIS tools must be available to SAR teams before an incident occurs.

In this lesson, you'll create a web map to prepare data for search operations. Your map will contain static base data showing regional boundaries and key features, as well as editable layers that can be changed as an incident develops. Then, you'll use the map to create a web app that even non-GIS professionals can use. Finally, you'll use the app to track a fictional SAR mission.

In this lesson you will build skills in the these areas:

• Mapping base and incident data
• Configure widgets in a web app
• Adding Situational Awareness and Smart Editor widgets
• Plotting Initial Planning Point and adding trail blocks
• Creating search assignments
• Mapping incident data

Learn ArcGIS is a hands-on, problem-based learning website using real-world scenarios. Our mission is to encourage critical thinking, and to develop resources that support STEM education.

Dataset Name: NI Greenspace Off-Road Trails LayerData Owner: Outdoor NIContact: https://www.outdoorrecreationni.com/contact-us/Source URL: https://www.outdoorrecreationni.com/news/greenspaceni-map/Uploaded to SPACE Hub: 04/07/23Update Frequency: AnnualScale Threshold: N/AProjection : Irish GridFormat: Esri Feature Layer (Hosted) Vector PolygonNotes: The Department of Agriculture, Environment and Rural Affairs (DAERA) and the Department for Infrastructure (DfI) on behalf of the cross-government Strategic Outdoor Recreation Group (SORG) commissioned Outdoor Recreation Northern Ireland (ORNI) to create the Greenspace NI Map. ORNI have commissioned Geolytical to help with delivering a high value map of all off-road trails and publicly accessible greenspace.The Greenspace NI Map is designed so:i. The target of 'Annual increase of the population within a 5-minute walk of quality green/blue space' proposed for PfG and other strategies can be objectively measured;ii. It can be used by government departments and agencies, Councils, and eNGOs, for infrastructure planning, gap analysis, resource allocation, site suitability assessments and demographic analysis (e.g., health and deprivation etc);iii. The data will be published on SpatialNI, OpenDataNI, and on occasions, OutmoreNI.The Greenspace NI Map is comprised of 3 layers –• NI Greenspace Layer• NI Greenspace Access Points• NI Off-Road TrailsGreenspace Map – Off-Road Trails is a map layer that includes single-use and multi-use trails that have been collated, mapped and validated as part of the Greenspace Mapping Project. Some of these trails are also published to the interactive map viewer OutMoreNI. Separate layers will be published of Greenspaces, Greenspace Access Points and Bluespaces.What is a trail?A Trail is included in the Greenspace Map if:1. It is Off-Road (or described as off-road by the source)2. It has Public AccessHow has the Off-Road Trails Layer been created?This layer has been created by harmonising, combining, and enhancing data from our data providers - Ordnance Survey of NI, NIEA, Forest Service, Sustrans, Outdoor Recreation Northern Ireland, DAERA, Armagh City, Banbridge and Craigavon Borough Council, Belfast City Council, Causeway Coast and Glens Borough Council, Derry City and Strabane District Council, Fermanagh and Omagh District Council, Lisburn and Castlereagh City Council, Mid Ulster District Council, Woodland Trust, Ulster Wildlife.Once the data was imported, geometries were checked for accuracy and attributes were added including an off-road filter.Who's using the Greenspace NI Map?The Greenspace map can be used by anyone who has access to a Geographical Information programme such as ESRI ArcGIS. Knowledge of how to use such programmes is also essential. Some examples of users are:Public sector - Incorporated as a layer, the dataset can be used alongside asset location data (GPs, pharmacies, schools) and indicator data (population and deprivation), to help inform and support the strategic planning of services and physical assets across the health economy.Innovators and researchers - NI's most comprehensive Open dataset of greenspaces can be used in a range of apps, products and innovations - providing the foundation to help create greener and healthier communities.FeedbackThink somewhere is missing from the data? Spot an inaccuracy in the attribution? Make us aware by emailing emma.taylor@outdoorrecreationi.comIf you have any further questions about the product, or would like to get in contact with a member of our support team, please reach out via our website.Currency and update frequency:The currency of the product is April 2023 and has an annual update cycle.Usage and DisclaimerThe greenspace layer has been created with the most recent data available at time of publishing.Best efforts have been made in the production of the Greenspace NI Map to ensure the accuracy of the data, however as the data has come from a range of capture methodologies and scales, they ma not reflect actual positional accuracy on the ground. There may also be a time lag between the content of the map at the time of creation and changes made on the ground.These layers should not be used to determine exact boundaries of land ownership Where ‘source’ of data is outlined, it should be noted that this is the supplier of the data input, it does not define ownership of the area. However, in some cases the source may be the landowner also.Some assumptions and generalisations have been made to make the mapping process more feasible - polygons, points and lines have been aligned to Ordinance Survey NI maps. Exact details of each polygon, point or polyline have not undergone field validation so discrepancies may occur.Although the layer only includes land where the public have access, not every polygon or polyline has complete public access and some areas may have restricted access. ORNI and its providers of open and derived data will not be held responsible for any loss, damage or inconvenience of any nature caused as a result of any inaccuracy or error within the data.

Here is a comprehensive description for an Esri Instant App customized for the International Joint Commission (IJC) to visualize real-time flow conditions in the Red River Basin using Esri’s Live Stream Gauges layer: Red River Basin – Real-Time Flow Conditions Viewer An Esri Instant App powered by Live Stream Gauges, developed for the International Joint Commission of Canada and the U.S. This Esri Instant App provides a dynamic, real-time view of streamflow conditions across the Red River Basin, integrating Esri’s authoritative Live Stream Gauges layer. The application supports the IJC’s transboundary water management responsibilities by delivering near real-time hydrologic data to decision-makers, researchers, and the public. Key Features: Real-Time Streamflow Monitoring: Displays hourly-updated measurements of stream stage (water depth) and, where available, flow forecasts from multiple trusted reporting agencies, including USGS, Environment and Climate Change Canada, and others. Binational Coverage: Focused on the entire Red River Basin, the app spans Manitoba (Canada) and Minnesota, North Dakota, and South Dakota (U.S.), aligning with the IJC’s jurisdiction and advisory role in the watershed. Interactive Map Interface: Users can select individual gauge locations to view current stage height, discharge rates, forecast trends, and sensor metadata. Symbols are color-coded by status and streamflow condition. Custom Basin Filters: Predefined filters allow users to quickly explore conditions by sub-basin (e.g., Pembina River, Assiniboine tributaries, Red Lake River), major hydrologic units (HUCs), or jurisdictional boundaries. Time Series & Trend Visualization: Where supported, users can graph historical data trends, examine hydrographs, and compare real-time conditions to seasonal norms. Mobile-Responsive Design: Fully compatible with mobile devices for field access by operational staff, researchers, and local water managers. Community-Sourced & Maintained: The Live Stream Gauges layer is supported by the GIS Community through Esri’s Community Maps Program. Local, state/provincial, and federal agencies contribute sensor feeds to maintain the reliability and accuracy of the data. Contribute Your Data: Agencies and partners interested in adding gauges to this platform can contact environment@esri.com for integration support and guidance. Purpose & Audience: This viewer enhances situational awareness for flood forecasting, water quality alerts, and emergency preparedness. It supports cross-border coordination by providing a common, open-access platform for binational water resource management, in alignment with the 1909 Boundary Waters Treaty and subsequent IJC directives. Whether used by IJC staff, Board members, hydrologists, municipal planners, or the public, the app improves transparency and promotes a shared understanding of hydrologic conditions across the Red River Basin.

Last Rev. 01/24/08 - E.Foster, P.E. - FSU/BSRCThe Historic Shoreline Database on the Web contains many directories of related types of information about beach changes in Florida over the past 150 or so years. The historic shoreline map images (see the Drawings directory) show precision-digitized approximate mean high water (mhw) shorelines, from the US government coastal topographic maps listed in the associated map bibliography files (see the Sourcebibs directory). These generally show data extending from the mid to late 1800’s to the mid to late 1970’s. The mhw positions have been extracted and tabulated (see the MWHfiles directory) relative to fixed reference “R” points along the beach, spaced approximately 1000 feet (300 meters) apart. Reference points not actually corresponding to actual “in the ground” survey markers are virtual “V” points. Mean high water positions have been and continue to be extracted from FDEP beach profile surveys from the 1970’s through the present and added to the tables. The beach profile data files from which mhw data have been extracted and added into the mhw tables can be found in the ProfileData directory and visually (for many areas) in the ClickOnProfiles directory. The beach profile files include elevation information along the entire length of the profiles. This profile data set has undergone up to fifteen additional quality control checks to ensure accuracy, reliability, and consistency with the historic database coordinate and bearing set. Note that any data deeper than wading depth have not yet undergone any extra quality control checks. Note also that there are *.cod text files of notes associated with the review of the profile data files.The digital historic shoreline map image files are given in a DWG autocad-based format, which should be usable on most versions, as well as many GIS systems. The Florida State Plane 1927/79-adjusted and 1983/90 horizontal coordinate systems are used. These are not metric systems, but with the proper software can be converted to whatever systems you may need. Each map image DWG file contains many layers, documented in an ASCII layer list archived with the DWG file.The database has been maintained and greatly expanded by E. Foster since approximately 1987 and by N. Nguyen since 1995. The initial map digitizing effort was done for FDEP at Florida State University, primarily by S. Demirpolat. Final processing and editing of the original map files to make them user-friendly was performed by N. Nguyen and E. Foster in 1995-7. Extensive quality control and update work has been performed by E. Foster since 1987, and by N. Nguyen since 1995. Field profile surveys have been performed by the FDEP Coastal Data Acquisition section since the early 1970’s, and by a number of commercial surveyors in recent years.The formats of the mhw tables and profile files are explained in text files included in the respective directories.Note that the digitized map image files were originally created in the UTM coordinate system on Intergraph equipment. The translation from UTM to the State Plane coordinate systems has resulted in some minor textual and other visual shifts in the northwest Florida area map image files.The dates in the map legends in the map images are generally composite dates. It is necessary to use the mhw data tables and map bibliographies for accurate dates for any specific location. The date ranges in the data tables relate to specific information given in the map bibliography files.2Generally it may be assumed that the historic shorelines have been digitized as carefully as possible from the source maps. If a historic shoreline does not contain a systematic position error and is feasible in a physical sense, the accuracy of the mhw position is estimated at plus or minus 15 to 50 feet (5 to 15 m), depending on the source and scale. This is as a position in time, NOT as an average mhw position. Data added from field surveys are estimated at plus or minus 10 feet (3 m) or better.It is to be noted that from the 1920’s onward, aerial photographs have usually been the basis of the US government’s coastal topographic maps. Prior to that, the method was plane table surveying. Along higher wave energy coasts, especially the Florida east coast, if there was significant wave activity in the source photography, it is very possible that the mhw was mapped in a more landward location than was probably correct. Alternatively, the use of photography sets with excessive sun glare may have caused the mhw to be mapped in a more seaward location than was probably correct. These effects have been frequently observed in comparisons of close-in-time FDEP controlled aerial photography with FDEP profile surveys. The use of some photography sets containing high wave uprush or sun glare is probable within the historic data. For example, on the east coast the 1940’s series maps tend to show the mhw more seaward than expected, possibly due to sun glare, and the 1960’s series tend to show the mhw more landward than expected. In the latter case, the effect may be due to the 1960’s being a decade of frequent storms. It is recommended that the analyst be aware that some of these effects may exist in the historic data. A questionable historic shoreline is NOT necessarily one to be discarded, just considered with allowance for its’ potential limitations.Using this database, it can readily be observed that the historic trends in shoreline evolution are very consistent with behavior expected from the longshore transport equation, well known to coastal engineers. This is a non-linear equation. Shoreline change can be expected to be linear or constant only in certain situations. It is NOT recommended that any analyst arbitrarily assume constant or linear shoreline change rates over long periods of time, which is often done but not supported by the evidence. The three primary factors controlling shoreline change are sand supply, wave climate, and local geographic features. In some parts of Florida, major storms since 1995 have also become important factors.