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Resource Hi-Light: The National Map

Updated: Mar 21, 2020

Bottom Line Up Front: The USGS National Map is a free resource that provides a wide range of useful information for small farms and homesteads, especially topography and water flow information.

USGS National Map Small Farm Ranch Homestead Topography Topographic Elevation Hydro
The USGS National Map has tools to increase your situational awareness on your farm.

When it comes to planning on your farm there are countless tools to use to help you make decisions. In our tech-driven society there many applications that provide us situational awareness that previous generations did not get to enjoy. But there is one tool that is timeless and can be used in conjunction with modern technology to provide information necessary for good planning: good ol' fashion maps.

I'm a bit of a map nerd. I spent an entire career in the military using them, studying them, navigating with them (fun fact: maps used for navigational purposes are called charts). If you don't know what to get me for Christmas, a road map from a truck stop is a fine last minute gift. So I love using maps to makes plans for our farm.

What sort of plans you might ask. There's plenty. Topography, elevation, water flow, flood zones, canopy coverage, soil types, vegetation growth potential, easements, distances, and area calculations are some the major reasons to use maps for your small farm planning.

There are plenty of mapping options out there, and I intend to write about several of them. Even Google Maps and Google Earth provide a good deal of useful data. But to take it up a notch in providing more tools for situational awareness, I want to introduce you to the USGS National Map.

The U.S. Geological Survey (USGS) creates and maintains all kinds of mapping tools. If you're a map nerd like me you can lose track of time while bouncing from one resource to another on their website. But what they make available in the National Map may be most useful for us as farmers. Here's how they describe the National Map on their website: The National Map is a collaborative effort among the USGS and other Federal, State, and local partners to improve and deliver topographic information for the Nation. It has many uses ranging from recreation to scientific analysis to emergency response.

Let's say you're thinking about buying some property to start a small farm on, or maybe considering renting some land to expand your operation. The National Map provides great tools for you to study the land and become familiar with what it has to offer along with potential challenges.

Perhaps you'd like to install a rain catchment system and gravity flow water out to your gardens or animals' water troughs. Using the topography tool will allow you to identify the high ground. Similarly you may want to build a pond where animals can come for a drink, or you may intend to pump out of it. Finding the low spots will allow you to find the best areas for that pond.

Does water flow across the property? All maps will show you rivers and creeks, but the National Map provides hydrography tools that show the prevailing path runoff water takes to reach those larger waterways. You may be surprised to learn there is a path - or a "wash" as we'd call it in my parts - that goes across the land you are considering for farm use. Now you know to avoid putting a road or fence in that area, or maybe adjust your paddock plan for those low areas. On our place we're using a wash to plant varieties of trees since this it has the best moisture availability on the farm - a huge benefit in our dry climate.

Are you building a fence? Using the elevation profile tool will depict the up-and-down terrain you'll fence over and give you an idea of the natural topography obstacles you may need to plan for.

There are many other applications for the National Map, but those I describe above are what I appreciate the most from this resource. Below are my basic instructions on how to use those tools. I encourage you to check it out and experiment with all the other tools the map has to offer - there may be items useful to you that I had not considered for my own operation.

The National Map provides great tools for you to study the land and become familiar with what it has to offer along with potential challenges.

Step 1: Go to the website for the USGS National Map:

Go into the National Map viewer and zoom in on the area you want to study.

Step 2: Begin using layer options and tools in the tool bar at the top of the map. Below I identify the overlay options.

USGS National Map Small Farm Ranch Homestead Topography Topographic Elevation Hydro Layers
There are numerous layers of data you can choose on your map.

Step 3: Select your preferred overlays. There are a lot of options, and I suggest you try them all. Here I use satellite imagery, contour line overlay, and hydrography information.

USGS National Map Small Farm Ranch Homestead Topography Topographic Elevation Hydro Imagery
Same area as above, but with the imagery layer option selected.
Now I added the elevation contours layer so I can see them on the imagery.
The hydrography dataset layer provides information on bodies of water and water flow.

Step 4: Use tools for measurements. For these tools, you must first select which one you want to use, and then you must 'activate' the tool to begin using it on the map.

For most tools you have to 'activate' it to begin using it.

Here I show how I use spot elevation to identify specific elevation measurements and draw accurate coordinates for a point. I selected three points. Each remains marked on the map until you clear the data, and a running list of your points is maintained in the Spot Elevation menu on the right.

Spot elevation tool being used.

Here I show how to use the elevation profile tool. This depicts the change in elevation between multiple points. To activate it you select the measurement tool in the Elevation Profile menu.

Click on your first point and continue adding points until you reach the end. Double click you last point, and it will generate the elevation profile for you. Drag your pointer across the profile and it will show you the change in elevation from the first point, and a red X shows that point on the map.

Elevation profile being used.

There are plenty of other options to explore within the National Map. It's free, it's easy to use, and it's worth checking it out. You may find it provides insight you didn't previously have on land you are considering or on a farm you are already operating. I'd like to hear from you if there are other tools you use from this map. Thanks for stopping by.

The Maverick Acres Blog: Tips and Strategies for Success on Small Farms and Homesteads.

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