The RI E911 Exposure Assessment

The Rhode Island Shoreline Change Special Area Management Plan (RI Beach SAMP), a program supported by many partners accross the state, works to study and understand how RI’s coastal communities will be affected by flooding and erosion in the coming years, and to assist municipalities in planning how to protect both people and property from these changes. One of the goals of the Beach SAMP program is to generate new data that can be used by communities and individuals to plan for the future. One of their many projects is the RI e911 Exposure Assessment, which utilizes the E911 sites data published here on RIGIS.

Background on the E911 DataThe e911 sites data (as well as E911 Roads, Driveways, and Fire Hydrants) is updated on a quarterly basis through the RI Enhance 911 Uniform Emergency Telephone System contractor. The points contained within the “sites” data represent every structure within the state that has a known address. This powerful dataset also provides the foundation for the RIGIS Address Locator.

The RI e911 Exposure Assessment consists of 22 Excel workbooks that cover the following coastal flooding scenarios:

  1. Flooding from twice daily tides, based on sea level rise (SLR) projections to the year 2100
  2. Flooding from coastal storm events, both with and without SLR.

Each of Rhode Island’s 21 coastal communities has it’s own Excel workbook that can be downloaded from the RI e911 Exposure Assessment website (link above); there is also a statewide (coastal) Excel workbook, containing information on all 21 coastal communities, that can be downloaded. Contained within each Excel workbook, is information on:

  • Building description – what a site point represents
  • Number of Exposed Structures – number of structures exposed by water depths over 0 feet.
  • Total Structures by municipality – the total number of strutures within a town
  • Total Structures SLR7, 100YR – the total number of structures exposed in the worst case scenario (SLR 7 feet with 100 year storm surge)
  • Percent Municipality – percent of exposed structures out of the total number of structures within the town
  • Percent SLR7, 100YR – pwercent of structures exposed during worst case scenario
  • 0-2 ft, 2-4 ft, 4-6 ft, >6 ft (each contained within a separate column) – total number of structures exposed at each interval (see project page for more details on this)
  • Mean Elevation – mean elevation of water for exposted structures in a town
  • Min/Max ft (each contained within a separate column) – the minimum and maximum level (in feet) of water for exposed structures within a town

Getting Ready to Use the Collector App

Recently I authored a blog post for the Environmental Data Center blog on setting up a feature class and Wbe Map for use with Esri’s Collector App. Based on discussions at previous RIGIS Executive Committee Meetings, I thought this posting may be of use and interest to the RIGIS community – especially the municipal-based RIGIS community.

This workflow walks users through the process of setting up domains within a file geodatabase, applying these domains to a feature class, preparing the feature class for use with the Collector App, uploading the feature class as a Service to ArcGIS Online and then configuring the Service and Web Map in ArcGIS Online. The result of this workflow will be a fully functional web map that can be used in conjunction with the Collector App.

In order to be able to complete this workflow, you will need access to ArcGIS Desktop software, and an ArcGIS Online Organizational account.

Read the Getting Ready to Use the Collector App blog post!

Implementing ArcGIS Open Data in Rhode Island

The concept of “open data” is not a new one, for years those of us in the GIS community have come accross this term to describe data that has been shared with no copyright restrictions (or other control mechanisms) for people to use and republish as they wish. Within the past two years, Esri has jumped into the open data world by beginning their ArcGIS Open Data initiative. This is a way for Esri customers to disseminate data through a customized ArcGIS Online web portal under an open data license. Organizations that implement ArcGIS Open Data are inherently agreeing to allow their users to download, use, edit and redistribute data for their own purposes. Since RIGIS currently distributes data under and open data distribution policy, the creation of an Open Data site was the next logical step. RIGIS is currently developing an ArcGIS Open Data site with the intention of expanding our user-base so that non-GIS users, desktop software users, and developers can have access to already distributed RIGIS data in a variety of useful open data formats, such as CSV, KML (Google Earth), SHP (Esir, QGIS, etc.) as well as APIs such as GeoJSON and GeoServices.

The RIGIS Open Data site will allow users to access these five different open data formats in a variety of ways. First, users can download the entire dataset (similar to how an entire dataset is downloaded from Second, users will be able to filter a dataset by attribute, or by area, and then download a “filtered” version of the data; this is particularly useful for large datasets, such as the E-9-1-1 Sites data. Third, users will be able to access and use data directly in ArcGIS Online web maps; this option may be ideal for non-GIS users interested in working with maps. Fourth, developers will be able to embed a stable link into web applications that will automatically have access to the most recent and up-to-date data available.

One caveat for the RIGIS community to be aware of, is that all data downloaded from the RIGIS Open Data site will be in the WGS 1984 Geographic (WGS84) coordinate system. Although ArcGIS Open Data sites can specify a local projection for all data downloaded, this will not be implemented as there is no way to control which Transformation is applied when data is uploaded or downloaded; as this could result in accuracy errors from data being improperly transformed we decided to eliminate this possibility entirely by using the Esri-recomended WGS84 coordinate system. Since the current RIGIS website ( will be maintained in tandem with the Open Data site, users will still be able to download SHP files in the Rhode Island State Plane (feet) coordinate system. All data downloaded will also be accompanied by full metadata.

Although the RIGIS Open Data site won’t be ready for it’s public debut until late Spring 2017, I’m very excited to be able to offer RIGIS users another way to use and access RIGIS data. There are some great examples of Open Data sites out there already, so if you want to poke around and see what they’re all about, here are some options:

Recap: RIGIS User Group Imagery Seminar

On August 19, an educational forum on aerial and satellite imagery available for Rhode Island was held at the University of Rhode Island’s (URI) main campus with the goal of informing attendees on a variety of online resources for image data of Rhode Island, with a heavy emphasis on RIGIS and the US Geological Survey (USGS); this forum also highlighted the new suite of ArcGIS Image Services featuring RIGIS data that are being developed by the Rhode IslandView.

There are three ways to download imagery from RIGIS. The majority of RIGIS imagery is available as tiled GeoTIFF and JPEG2000 format files, however historical imagery is available as tiled MrSID format files (although these will be transitioned over to JPEG2000 files in the future).

  1. Download individual imagery tiles using an interactive web map. These can be accessed from each imagery description page, and allow users to search by address to easily zoom to an area of interest.
  2. Download tiles on a municipal basis. This allows users to select a town and download all tiles with the assistance of a download manager program, such as DownloadThemAll!
  3. Download the entire imagery collection with the assistance of a download manager program. This option is ideal for users interested in working with statewide imagery; however this option requires adequate storage space as most collections are very large.

Currently RIGIS shares imagery online as tiled map services. These are essentially static “pictures” of a map containing GIS data using ArcGIS technology. Map services are drawn when requested by the user, they are great for real-time display, and if cached, provide a quick way to serve imagery up on the web. The majority of RIGIS map services are hosted “in the cloud” making them faster and more reliable (e.g. if there is severe weather and power at URI goes down, you can still access these services).

There are two ways to access RIGIS ArcGIS Online Tiled Map Services:

  1. Via ArcGIS for Desktop.
    • From the Add Data dropdown, select “Add Data from ArcGIS Online…”

  • Type RIGIS in the search bar, and press enter.
  • Locate your year of interest from the results. You can view more details about the service by clicking the details button, or you can add it directly to your map. See below.

  1. Via ArcGIS Online.
    *Note: This requires a user account! This can be through your organization, or it can be a FREE user account. For information on how to sign up for a free account, visit this blog posting.

    • Sign in to your account.
    • Once signed in, click Map from the top toolbar.

  • When the Map page opens select Add > Search for Layers.

  • Next, in type RIGIS in the “Find” search bar, and press enter. Make sure that the “In” option is set to ArcGIS Online.

  • From the results list, select and click the Add button to add the layer to your map (this changes to Remove once you have added a layer). When you are done, click the Done Adding Layers at the bottom of the dialog.

These map services are in the process of being retired and replaced with ArcGIS Image Services by Rhode IslandView.

Image services are another way of sharing raster or imagery data through an online web service. Image services allow users to work directly with the data by changing the appearance of the data (e.g. band combinations to view near infrared when conducting vegetation-related studies), have great print quality and allow users to download the data. Although image services are not hosted in the cloud, and can be slightly slower than tiled map services, the degree of functionality they provide makes them the number one choice for using and accessing online imagery.

This transition will occur sometime later this fall, and the RIGIS community will be alerted to any and all changes via the RIGIS-L listserv.

Gridded Soil Survey Geographic (gSSURGO) Database

The Gridded SSURGO (gSSURGO) is a complimentary product to the traditional SSURGO data made available the USDA-NRCS. All attribute tables associated with traditional SSURGO data are contained with the gSSURGO database. These data are stored in an Esri File Geodatabase and are easily combined with other national raster datasets such as the National Land Cover Database (NLCD) or the National Elevation Dataset (NED), to name a few. Because file geodatabases offer the capacity to store much more data, the gSSURGO covers wider spatial extents than traditional SSURGO data, giving the NRCS the ability to make these data available as statewide, or even Conterminous United States (CONUS) tiles.

The USDA-NRCS has a great description page dedicated to the gSSURGO data. Here users will be able to read a much more detailed description of what the data are, some release notes for the FY2016 version, informaiton on National Value Added Look Up Table database, metadata information, recommended citations, techincal information and ordering information.

Since RIGIS offers up-to-date Soils data contributed by the Rhode Island USDA-NRCS office, we will not be hosting the gSSURGO database for the state, however interested users can easily download these data from the USDA-NRCS Geospatial Data Gateway following the instructions below.

1) Click the Get Data button on the right side of the page (see below).

2) Select Rhode Island from the drop down menu.

3) Highlight all Counties (hold SHIFT and left mouse click), and click the >> button (see red box below) to select all counties.

4) Click the Submit Selected Counties button (see purple oval below).

Note: This will generate a popup notifying you that it might be better to download the data by state instead of counties, however for the purpose of this blog I felt it would be best to show the county-based download option.

5) From the selection list that appears, scroll down until you see the heading “Soils” (this will be towards the bottom of the list).

6) Check off the box for “Gridded Soil Survey Geographic (gSSURGO) by State”, and click the green continue button at the bottom of the page (see below).

7) On the next page, ensure that you have the FTP download option selected at the bottom of the page; this is the FIRST option. Click the green continute button.

8) Complete the contact information form on the next page and click the green continue button to review your order.

9) Once you have reviewed your order, click the green place order button on the lefthand side of the page. Your data will then be processed and emailed to you with a download link.

New Data – Topobathy Lidar bare earth DEMs for Southern RI

Between July and August of 2014 the National Oceanic and Atmospheric Administration (NOAA) National Geodetic Survey (NGS) collected topobathy LiDAR for 2,775 miles of the Atlantic Coast from Rhode Island to South Carolina. This provides coverage of areas highly damaged during the landfall of Hurricane Sandy in late October 2012. In Rhode Island, this project covered a total area of 205 square miles along the south coast, from Westerly to Narragansett. These data have been available for download from RIGIS as raw, vendor-created LAS files since the inception of the new website, however I am happy to announce the release of bare earth Digital Elevation Models created and tiled by RIGIS.

For those of you not familiar with topobathy LiDAR, here is some background information on how it is collected, and some of the ways it can be used:

As most of you probably know, LiDAR, or Light Detection and Ranging, is a method used to remotely study the surface of the earth. LiDAR data is most commonly collected through the utilization of airplanes and helicopters; these carry the instrumentation necessary to collect these data. This specialized instrumentation consists of a laser, a scanner and a GPS receiver. This equipment collects information about the surface of the earth through a series of pulses of light, creating a three-dimensional representation of the surface.

Airborne topobathy LiDAR is collected in a similar manner to the traditional terrestrial LiDAR described above, however in addition to the near-infrared wavelength (1000 – 1500 µm) laser, a blue-green wavelength ( 532 µm) laser is utilized.  This blue-green wavelength laser allows for penetration through the water column.

This penetration of the water column allows data users to visulaize near-shore bathymetric environments. This can be great for use in a variety of modeling applications such as inundation modeling, sea level rise modeling, shoreline delineation, habitat mapping, inland watershed applications, restoration planning and coastal geomorphological analyses to name a few.

Topobathy LiDAR offers a seamless transition between land and submerged areas, something traditional LiDAR lacks. Although this topobathy does not provide full coverage of the Rhode Island coastline, I hope that the RIGIS community finds these data useful. These data are offered as tiled GeoTIFF images, in the Rhode Island State Plane Feet coordinate system, with both horizontal and vertical units of feet. Get started by downloading it here!

Above is a sample of the NOAA Topobathy LiDAR for Rhode Island. This is just a mosaic dataset of all individual tiles available for download from the link above!

Above is a sample of the NOAA Topobathy LiDAR for Rhode Island. This is just a mosaic dataset of all individual tiles available for download from the link above! 

For additional information on how to develop your own topobathy DEM using the raw LAS files we offer, visit this blog posting from the Environmental Data Center at URI.

To learn how to create beautiful visualizations with topobathy DEMs, click here.

New Coastal Lidar and Imagery Available


There are two new collections of coastal LiDAR data available for download via the Elevation and Bathymetry section of this website. While neither collection provides full coverage of Rhode Island, both provide users with high-quality elevation data that can be used in a variety of ways.

First, is the 2014 NOAA post-Sandy Topobathy LiDAR collection that provides coverage of RI’s south coast towns. Currently these data are only availabe in LAS file format from RIGIS, however we hope to make tiled Digital Elevation Model (DEM) data available in the future. For users wishing to access and use DEM data now, please visit the NOAA Digital Coast Data Access Viewer, where these data can be downloaded as DEMs (a blog posting on how to do this will be forthcoming!).

Second, the 2014 USGS CMGP Sandy LiDAR collection that also provides coverage of RI’s south coast towns, as well as coverage of the southern portion of Narragansett Bay towns such as Jamestown, Newport, Middletown and Little Compton. These data are available for download in both LAS file format and as tiled DEMs. Both collections are provided in the Rhode Island State Plane – feet coordinate system.


There is also one new collection of coastal orthoimagery available for download via the Imagery section of this website. While these data do not provide full coverage of Rhode Island, this high-resolution, 35-cm GSD, 4-band imagery will be useful in a variety of ways.

These data were collected by NOAA simultaneously with the NOAA topobathy LiDAR, and provide coverage of RI’s south coast, as well as coverage of the southern portion of Narragansett Bay towns such as Jamestown, Newport, Middletown and Little Compton. These data are available in both GeoTIFF and JPEG2000 file formats, and are provided in the Rhode Island State Plane – feet coordinate system.

Homeland Infrastructure Foundation-Level Data ArcGIS Online Open Data Site

Historically, access to the Homeland Infrastructure Foundation-Level Data (HIFLD) has been restricted to applicants meeting a variety of criteria, such as working for a federal government agency, or state emergency management agency. With the release of their new ArcGIS Online Open Data website, the HIFLD has made data previously contained within the Homeland Security Infrastructure Program (HSIP) databases available, and open, to the public.

Currently available are over 270 public datasets that are downloadable in a variety of useful formats, such as CSV, KML, and Shapefiles. These are also all available as APIs, such as GeoJSON and GeoServices for easy compatibility with web applications.

There are a wide variety of data categories to choose from, ranging from Agricultural data, to Energy data, to water supply data. All data is downloadable, either as a full dataset, or as a filtered dataset (i.e. you can filter for features only occurring in Rhode Island and download those).

Prior to downloading data, users can read brief dataset descriptions, explore the attribute table, and view the data in an interactive web map. Once downloaded, users have access to full metadata records.