Mapping and Inventory of Forest Roads with Global Positioning Systems (GPS)

 

Mark Milligan
President, GeoTech Systems
Tallahassee, FL 

 

ABTRACT

The forest industry constantly faces inventory demands for the purposes of managing timber resources.  Foresters also get involved with the inventory of other natural, environmental and cultural resources on a periodic basis.   Other than timber resources and land value, road infrastructure (roads, bridges, culverts, etc.) is by far the most valuable asset managed by forest managers and landowners.  However, when it comes to managing these resources, information is often lacking or very poor.  This can result in misallocation of resources and resulting inefficiencies.
 

The use of Global Positioning Systems provide foresters with the ability to map and inventory forest roads, bridges, culverts, low-water-crossings, gates, etc.  Not only can accurate maps be produced with accurate positions and lengths of roads and segments, but attribute data can easily be tagged with each mapped feature.  These attributes contain information such as road classification, surface type, width, condition, elevation with respect to grade, road name and others. Likewise, similar attributes and their values can be collected for the other feature types.  This information can then be used in a Geographic Information System (GIS) to query the collected data for the purposes of managing these resources.  For example, a map could easily be produced in minutes displaying all culverts that need replacement, or all roads in poor condition.
 

Two such inventories are presented in this paper.  Both were conducted for the Florida Division of Forestry on Lake Talquin and Blackwater River State Forests.   Both instances illustrate the underestimation that forest managers can make when it comes to road infrastructure.  For example. for Lake Talquin State Forest the miles of roads were estimated at more than 50% below what was actually mapped. Even more telling, the number of crossings (bridges, culverts, washouts, etc.) were underestimated by more than 500%. (Final numbers for Blackwater will be available by July).  These numbers suggest that forest managers should at least investigate the possibility of conducting such an inventory.