Repeat Photography Monitoring Made Easy
G. Allen Rasmussen and Kathy Voth
Revised 2024 by
Eric Thacker, Randall Violett, Ruger Carter, and Dallen Smith
What Is Monitoring?
Professional land managers use monitoring as the basis for evaluating and making management decisions. The Society for Range Management has defined monitoring as, “The orderly collection, analysis, and interpretation of resource data to evaluate progress toward meeting management objectives” (1989). The amount of time and expertise this implies scares many people away. However, some monitoring techniques are not that complicated. At the most basic level, monitoring is defined as "to watch, observe, or check usually for a specific purpose" (Merriam-Webster, n.d.).
There are many monitoring techniques. Here, we will discuss one of the simplest, cheapest, and quickest methods: repeat photography. By following the easy steps outlined here, range users will collect data and record interpretations over time to provide proof of change and management efforts.
Step 1: Get the Equipment
Equipment:
1. Smart phone or digital camera.
2. GPS unit (if camera or phone does not have this function).
3. Photo board
4. Reference pole.
5. Notebook or digital notes.
• Smart phone: Most smartphones/cell phones are adequate at taking good quality photos and have GPS capabilities. It is best if the phone is able to take 8-megapixel pictures or better. The data and photos should be saved externally on cloud-based storage or a storage device such as an external hard drive.
• Digital camera: Most cameras in use today are digital and should take pictures that are 8 megapixels or greater. We recommend that if you use a digital camera, purchase one with GPS capabilities.
• GPS unit: In the absence of a smartphone, it is necessary to have a GPS unit to mark where the key areas are and where each photo is taken only if your phone or camera is not capable of georeferencing photos.
• Photo board: Placing as much information in the picture as possible eases recordkeeping in the future. Your photo board will appear in every picture you take, so be sure the photo includes the location and the key species of the monitoring site. Your photo board can be an inexpensive whiteboard, or a clipboard with a plastic sheet, or even just a sheet of blank paper. All will allow you to write the appropriate information, take the picture, and then move on to the next site.
• Reference pole: Your reference pole gives a sense of scale in your photograph. It allows you and others to see changes in the vegetation height and structure over time. Your reference pole should be at least 1 meter long. A piece of PVC pipe works well. Paint the bottom half red. Duct tape wrapped in the middle makes a good dividing line. The two colors are an important part of making it easy to estimate vegetation height. Steel t-posts are commonly used as markers because they are permanent and can be used similarly to a reference pole.
• Notebook: With one place to store your photos and your evaluation sheets, you will have quicker access to your information in the future. Using a notebook also makes it easier to carry photos from the past year into the field with you to be sure you are repeating photos at the same locations every time. A three-ring binder works well. We suggest attaching your photos to your evaluation sheets (see Figure 1 for an example). This information can also be collected and stored digitally via several software options that allow you to enter notes and photos.
Step 2: Choose a Location
Your photo monitoring will be most useful if you select “key areas” to monitor. If you are monitoring on federal and state grazing allotments, we strongly encourage collecting photos at established key areas that have previously been established by range personnel. This helps create a more complimentary monitoring program with existing monitoring protocols. A key area represents the area you are managing and acts as an indicator of changes that may be taking place. The greater the variety in your terrain, the larger the number of critical areas you will need to represent the area being monitored. Keep the following guidelines in mind when selecting your photo monitoring location:
1. Choose a spot you will have time to visit and monitor. Pick areas that are a high priority for your operation and add others over time.
2. Ensure that the area is representative of a larger area. Choosing areas where livestock congregate (watering points or fence lines) or where livestock never graze will give you basic comparisons. However, these areas may not adequately represent the larger area and how your management affects it over time.
3. Select enough key areas to represent the area you manage adequately. An advantage of having more than one key area is that it ensures small local events, such as fires or floods, do not misrepresent conditions in the larger area.
4. Compare photo stations in grazed and ungrazed areas to help you evaluate the effects of grazing. Ensure the sites are similar in soils, topography, and precipitation. If you would like more information on picking key areas, see Sampling Vegetation Attributes available from the Bureau of Land Management (Coulloudon et al., 1999).
Step 3: Take the Picture
Every picture you take should include the following, in order of importance:
1. Landmark
2. Photo board.
3. Reference pole.
• Landmark: A distinctive, permanent landmark is critical to find the photo point in the future. Repeating photos at the same site annually allows managers to demonstrate what management has done. When taking photos, be sure the frame includes a skyline. Including a skyline when photographing a riparian area can be particularly challenging. Are there rock outcrops, mountain slopes, or other geologic features that will remain the same over long periods? The photos should include a landmark that can be found repeatedly. Landmarks will help others to know they are looking at the same site.
• Photo board: After writing the date and location name on the photo board, place it in the picture’s foreground. Be sure the sun’s glare will not prevent reading the board’s information once the photo has been taken. With the photo board visible, check to see that landmarks are visible in the frame.
• Reference pole/post: Place the reference pole the same distance from the point of origin every time. Because the photo board is in the photo's foreground, it can easily be used as the “point of origin.” Fifty feet from the point of origin is most commonly used to locate the reference pole. In many areas, such as a riparian area, willows can fill in overtime, making the pole challenging to see, so it might have to be moved forward over time. If the pole is moved, be sure to note this as part of the site observations.
Figures 1–3 show examples of monitoring photographs ranging from useful to not useful.
Figure 1. Useful Photographs
Notes. These example photographs have everything needed for monitoring changes. They each have the date, location, a reference pole, and some permanent features that can be recognized. Note how the background skyline makes it easier to find these sites in the future.
Reference pole
Reference pole able as
Notes. These photographs could be more useful. All have the date, location, and reference pole, which makes them very useful for monitoring. However, because there is no permanent feature or a distinguishable skyline, relocating them will take time and effort.
Notes. These photographs are the least useful for monitoring. They are nice landscape pictures, but they do not contain the date, location, or a reference pole. These are very difficult to use for monitoring, and then only by the person who took the original photo. To make them more usable, they should be attached to a sheet with the date and location. A map of how to find the site would be valuable as well.
Step 4: Record Site Location
It is essential to mark the location of each photo point on the GPS or smartphone. This can be done by ensuring location services are turned on for the photography app so that each photo is georeferenced. Installing a steel t-post or pin at the site ensures that the photo is taken at the exact location each time.
Figure 3. Not Useful Photographs
Step 5: Notes, Picture, and Data
The last steps include organizing photos, including notes for each photo, and placing them in a notebook or file. Although some people use computer systems to store data and photos, this is the simplest method. It is also helpful to briefly interpret what you observed while taking your photos. It does not need to be long just a few words about what is happening at the site.
For example:
• "Sagebrush seedlings are starting to show. I should start thinking about burning this area in the next 5 years or so!"
• "Grasses are becoming more dominant. I will try to adjust the season of use to an early part of the year to get the sedges back."
• "Sagebrush has increased, and grass cover is declining. I am seeing lots of bare ground and worry about future erosion."
Step 6: Repeat the Process
The real value of photo monitoring is realized as multiple years of photos are viewed together. Photos must be taken at the same time of year. The ideal approach is to take photos at the same time at the same locations every year. If photos are not taken at the same locations and time annually, it weakens the value of the photo sets.
General Recommendations
To make the most of repeat photography monitoring, be sure it includes the following:
1. Quality photos with the:
• Skyline or permanent features for easy relocation,
• Reference pole placed the same distance from the origin point, and
• Photo board with date and location
2. Written notes concerning the use and events on the site.
3. Observations and interpretation of the management effects on the site
4. Storage strategies for photos and notes.
5. Repetition of the process over time.
Picture Credits
Photos were provided by authors.
References
Coulloudon, B., Eshelman, K., Gianola, J., Habich, N., Hughes, L, Johnson, C., Pellant, M., Podborny, P., Rasmussen, A., Robles, B., Shaver, P., Spehar, J., & Willoughby, J. (1999). Sampling vegetation attributes: Interagency technical reference. Bureau of Land Management National Business Center.
Merriam-Webster. (n.d.). Monitor. In Merriam-Webster.com dictionary
Society of Range Management. (1989). Glossary of terms used in range management (4th ed.). (Glossary Update Task Group, Thomas E. Bedell [Chair], Eds.). Rangelands Gateway. https://rangelandsgateway.org/glossary
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December 2024
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