Updating regional road networks in forested regions for environmental assessment
Research Idea Scope
Road features have both positive and negative effects on their surroundings. While roads provide transportation for people and goods, there are a significant number of negative ecological impacts that can stem from road networks. Roads can increase sediment production, stream temperatures, and the total amount of non-point source pollution within a drainage basin and any receiving features such as streams, lakes, and ponds. The purpose of this proposed research is to develop an updated and improved roads data layer for primarily forested watersheds that can be used in ecological analysis and planning. Through the use of multi-temporal aerial imagery and GIS analysis, previous research concluded that between 75% and 250% of roads in heavily forested regions are not included in some state “framework” roads layers, as shown for four primarily forested watersheds in Michigan’s western Upper Peninsula. The number of road/stream crossings in this region increased over 120% based on the updated road network. This improved road network was also used to determine where potentially impacted wetlands may exists and indicated that for two watersheds, between 68% and 74% of the total wetlands were potentially impacted through proximity to the road network. Additionally, this type of analysis that incorporates multi-temporal aerial imagery could be used to map the geospatial progression and patterns of an expanding road network in primarily forested areas, such as those experiencing clear-cut logging practices or rural low-density development, with an additional focus on modeling the amount of erosion that is potentially occurring expanded road networks and analysis into how it may be impacting nearby hydrological networks. Objective 1: Update and improve current State framework roads GIS data layers for heavily forested regions using multi-source, multi-resolution image analysis methods demonstrated in a large study area in northern Michigan that can be easily extended to other regions in the country. Objective 2: Identify, map, and quantify potential environmental impacts that an updated road network has on its surroundings (such as hydrologically impacted wetlands, road/stream crossing issues, and the potential amount of sediment erosion and water runoff analyses).
Urgency and Payoff
While multiple studies have examined and quantified the effects roads have on landscapes, many may have been based on incomplete data sets, which can significantly underestimate the spatial extents and quantity of roads within a region of interest. In addition, information pertaining to the specific types of roads and the quantities of each type has not always been quantified. Attributes of road segments are important to recognize due to different effects different types of roads have on their surroundings. Therefore, an updated and improved road data set is necessary in order to draw inferences that quantify the total impact that a road network has on a landscape. Through conducting an analysis that is not only concentrating on the mapping of forested roads, but also in locating where the updated road network is potentially causing environmental impacts, a better understanding of where watershed vulnerability is occurring will be gained for forested regions. This will be beneficial for environmental managers and will aid in a more accurate understanding of where such vulnerabilities exist on a local and watershed basis. This will also be help natural resource and road managers understand where linkages between ecological and human resources are strained.
David Banach Michigan Technological University 734-994-7225