| f the challenges faced when using traditional land | | | | other earth science applications. Depending upon |
| surveying methods is the necessity of surveying | | | | its intended use, a vegetation survey may indicate |
| areas that are covered by thick vegetation. Some | | | | areas with vegetation and those without, or the |
| surveying projects require the measurement of | | | | species of plant and their density and location. |
| such vegetation, while most applications require | | | | These maps may be used to identify sensitive |
| measurement of the terrain itself, rather than the | | | | ecological areas (such as wetlands), map the |
| vegetation covering this terrain. Topographic | | | | spread of plants, or examine environmental |
| surveys may or may not require the | | | | changes following natural or man-made events. |
| measurement of vegetation, depending on their | | | | In cases where vegetation surveying is desirable, |
| intended purpose. | | | | measurements may be taken using aerial |
| When on the ground, land surveyors may find | | | | methods or using a surveyor's transit or total |
| that traditional surveying equipment is blocked by | | | | station to measure vegetation height and to lay |
| large trees or other obstructions. They may even | | | | out a grid of the terrain, onto which vegetation |
| be unable to traverse the land because of steep | | | | can be measured. The same grid can then be |
| hills, inconvenient streams, or other natural or | | | | used by another surveying team after a period of |
| man-made features. Combined, these features | | | | time to measure changes in vegetation and |
| may make surveying difficult or even impossible | | | | terrain. |
| from on the land itself, particularly in undeveloped | | | | While topographical maps may display vegetation |
| areas. However, there are ways around these | | | | or man-made features, a digital terrain model (also |
| obstructions which allow surveyors to create | | | | known as a digital elevation model) generally only |
| accurate and precise surveys. | | | | represents the ground topography and terrain |
| Some methods of surveying can penetrate trees | | | | underneath the vegetation. Digital terrain models |
| and ground cover. Among these is LiDAR, a | | | | may be referred to as bare-earth models, while |
| laser-based method. Because the laser device is | | | | Digital Surface Models include features such as |
| flown over the area in an airplane, it is ideal for | | | | vegetation. |
| heavily forested areas where access on foot | | | | There are a variety of surveying methods used |
| may be difficult or impossible. | | | | to create topographic surveys or digital terrain |
| Other surveying applications, on the other hand, | | | | models, such as direct surveying (with a |
| require measurement of the vegetation. Similar | | | | surveyor's transit or total station) or remote |
| aerial methods do not penetrate tree tops, and | | | | sensing technologies such as aerial and satellite |
| therefore can give an idea of the vegetation while | | | | imagery, LiDAR methods, and photogrammery. |
| still allowing the surveyor to work from a | | | | The most appropriate method depends on the |
| distance. | | | | area being surveyed and the amount and type of |
| One type of surveying, known as 'vegetation | | | | data required. Some surveying methods used to |
| surveying,' is particularly interested in the | | | | create these models, such as radar, reflect the |
| vegetation found in a given area. Unlike standard | | | | highest elevation point on a given location, |
| land surveying, vegetation surveying often depicts | | | | whether this is the top of a tree or building or |
| rough boundaries, not strict lines. Vegetation | | | | bare ground, while others are intended for the |
| surveying, or the mapping of plant habitats, is a | | | | measurement of the terrain itself. |
| valuable tool for botanists, environmentalists, and | | | | |