Modeling Trail Degradation Using Field and GIS Methodologies: A Comparative Study.

Abstract

Trail degradation is a problem that park managers continually battle. A relatively recent US General Accounting Office report states a 4 billion dollar maintenance backlog has developed in the National Park System. Given the heavy use of trails, it is likely that a substantive part of this backlog is related to trail degradation. The ability to quickly and accurately predict trail problem locations would greatly enhance the efficiency of both preventing and mitigating these problems. To date, some studies have modeled trail degradation, but these methods rely almost entirely on field-collected data, which is expensive and time consuming to obtain. This study explores the potential of GIS to efficiently populate degradation models of incision and width with landform variables. Issues related to GIS data resolution for use in these models are examined through a stepwise regression procedure. Results suggest that models based on GIS-derived data perform as well or better than models based on field-measured data. These results also suggest that there may be a relationship between trail degradation and landform characteristics such as slope, trail grade, trail alignment angle and landform curvature. Specific degradation problems are further examined using spatial and nonspatial clustering techniques and the results suggest that degradation problems are spatially clustered. Visual examination indicates that certain landform characteristics are coincident with statistically significant clusters of both high and low values of trail degradation.

This work bolsters the argument for the use of GIS derived data in trail degradation models. With these procedures designers and managers can quickly and efficiently use the models to quantify the degradation sensitivity of existing trail sections and alternative new trail designs. In addition, based on the findings in this study, researchers may begin to measure some landform attributes with GIS to reduce the costs of field work. Research implications also suggest new areas of model development related to the spatial scale of factors that appear to influence trail degradation.