Customizing US National Grid Maps for Post-Storm Recovery
When people in New England hear the words “National Grid,” thoughts automatically turn to the utility company. Many people are unaware that the U.S. National Grid exists, and that it is different from the aforementioned electricity and natural gas provider.
The U.S. National Grid is a standardized, grid-based reference system that is designed for use in search and rescue. This system is ideal for identifying specific locations and regions, and works regardless of existing jurisdictional boundaries, making it an ideal search and rescue tool to implement after a large-scale disaster such as hurricanes or wildfires.
The U.S. National Grid Information Center website provides downloadable U.S. National Grid data sorted by FEMA Regions. These are the 10 standard FEMA regions that each contains a FEMA regional office. Each region serves particular states, and National Grid data for these states can be downloaded by state or for the entire region. All downloadable data are available by UTM Zone designation. For example, Rhode Island is available for download in UTM Zone 19N since the state only spans one UTM Zone. However, a state like Texas is available for download in 3 different UTM Zones (13, 14 and 15) as the state is so large.
Once downloaded, it is possible to create useful maps that can be easily used by first responders. The Mapping Support section of the U.S. National Grid Information Center website provides downloadable templates and instructions for creating Map Books using ArcMap. Below, we will walk through the creation of a map book for Fire Island National Seashore in New York. If you are unfamiliar with this area, please orient yourself here.
What is a map book? The easiest way to describe a Map Book is to compare it to a road atlas. A map book will similarly contain individual pages of maps that are referenced to an index map at the front of the book, usually using some type of grid system. Each individual page within the map book will provide a very detailed look at one small section of the larger area. Map books can be easily created using ArcMap’s Data Driven Pages toolbar. For more information on building map books using ArcGIS, please visit the ArcGIS Resources page.
First, download the U.S. National grid data for your area of interest (AOI), as well as the ArcMap Project template and associated instructions. These all may be found at the Mapping Support section of the U.S. National Grid Information Center website – look under the “Mapping Support” section for the ArcMap project template and instructions. Next, open the Data Driven Pages toolbar. To do this, go to Customize > Toolbars and select Data Driven Pages; this toolbar can be docked in your interface.
To begin, open the “NG1K.mxd” ArcMap Project template document downloaded from the Mapping Support page. When you open the document you will see a pre-made map layout containing the Esri World Imagery Basemap, a series of grids and informational details at the bottom of the layout. If you look at the Table of Contents, you will see that there are also two data frames and missing data which is indicated by thenext to each data layer.
First, you must set the coordinate system for both data frames within the Table of Contents. By default, they are set to UTM Zone 15N, but you will need to change this to match the projection of the data you’ve downloaded for your area of interest from the USNG website. To do this, double click on the “Layers” data frame and navigate to the Coordinate Systems tab. Select the appropriate zone from the list (for this example, UTM Zone 18N). Click Apply, and OK.
You will need to repeat this for the data frame titled “Local Indicator” as well.
Next, double click on the 1 K Polygons layer and open the Properties dialog. Navigate to the Source tab and click the Set Source Data button at the bottom of the dialog box. Now, it is necessary to navigate to the folder containing the downloaded data for your area of interest. Select the shapefile and click OK.
Once added, click the empty checkbox next to the 1 K Polygon layer to turn the layer on, and switch to the Data View. Turn off the Basemap and zoom to the 1 K Polygon layer. Now we will select the U.S. National Grid polygons that intersect the AOI.
To do this, we will add a polygon shapefile of the study area to the map document and zoom to this layer. We will then open the Selection > Select by Location tool and select all U.S. National Grid polygons that intersect the polygon layer of the park boundary.
As you can see above, the grid cells that intersect the park boundary have been selected in red. Close out of the Select by Location dialog and export the selection. Do this by right clicking the 1 K Polygon layer, navigate to Data and select Export Data (see red circle below). This will open a dialog in which the file name and location can be specified for the new layer (I have named the layer “map automation selection”, but you can choose another name). Once completed, add the new layer to the map document.
Choose an appropriate symbology to represent your selected USNG polygons; I recommend selecting a hollow polygon with a red outline with a thickness of 2.
Next, set the map scale to 1:6,000 and switch back to the layout view.
It is now time to set up your map book. Click on the Data Driven Pages Setup icon on the Data Driven Pages toolbar, and navigate to the Definitions tab. Use the following image to set the correct parameters:
Next, navigate to the Extent tab, and select Center And Maintain Current Scale. When you are finished, click OK to finish creating your map book.
Now you can add other layers, such as roads, the park boundary and other useful layers to customize your map book even further. You can also customize the legend information at the bottom of the page. It will be important to update the data sources and credits.
Finally, export the map pages to a PDF document. To begin, go to File > Export Map and select PDF as the file type, and navigate to the Pages tab. Here, select to export All pages as a single PDF file. It is also possible to export All pages as multiple PDF files (multiple PDF files is an option in the “Export Pages As” drop down menu).
This blog posting was developed with the support of a competitive grant (cooperative agreement number P09AC00212; task agreement number P13AC00875) from the National Park Service in partnership with the North Atlantic Coast Cooperative Ecosystems Studies Unit.