If you're developing a plot of land, a digital terrain model can be a critical tool to help you create a development plan. If you're hiring someone to do this type of survey for you, there are several questions you may want to ask. Check out the following ideas:
1. Does Your Digital Terrain Model Provide More Information Than a Contour Map?
Contour maps can be helpful when you are developing land, but in most cases, contour maps don't provide as many details as a digital terrain model. Most contour maps connect elevation points that are the same elevation, but they don't include details on intermediate points. If you're used to working with contour maps, you may want to talk with your survey professional about what additional advantages you can get from a digital terrain model.
2. What Tools Do You Use to Create the Map?
You may also want to find out which approach the survey company uses to create their digital terrain models. Generally, these professionals don't use the same equipment traditionally used by surveyors. Instead, they use radar satellite images obtained remotely. If they are using airplanes or drones to gather information, you may want to learn more about that process, its accuracy levels and the costs involved.
3. What Is the Projected Resolution of the Digital Model?
Depending on the surveying tools used, the resolution may fall into different ranges. For example, some digital terrain model surveys may only have a resolution of 10 metres. You may need better resolution or less accurate resolution depending on how you plan to use the survey model.
4. What Does the Digital Terrain Model Include?
It's also essential to ensure that your terrain model includes the details you need. Some models only include the swells and depressions of the Earth's surface, while others include man-made structures such as fences and buildings. The first tends to be called a bare-earth model, while the latter is a digital surface model. Make sure you are on the same page as the surveyor you hire, so you know what to expect.
5. Can You Create Models of Movement?
The advantage of a digital terrain model survey is that they are 3D interactive models. In some cases, they can also include movement in different ways. For instance, the model can include the flow of water through the area or simulations of avalanches or landslides.