Remote sensing of off-road vehicle impacts to soil and vegetation on the Lac du Bois rangelands, Kamloops, British Columbia

Land use management to provide areas for off-road vehicle (ORV) recreational activity, and to control and reduce the ORV impacts, requires information on the rapidly changing conditions. The objective of this study was to develop a remote sensing method to monitor ORV impacts to soil and vegetation on the open lands of British Columbia. To complement available aerial photographs of the Lac du Bois range-land study area for 1971, 1975 and 1977, two scales and formats of aerial photographs were flown in the summer of 1979. A ground survey program was designed to support the aerial photograph interpretation of ORV impacts. The ORV trails, which were mapped from the aerial photographs, had an increase in bulk density and a decrease in moisture content and organic carbon. Regression analysis of the soil variables versus optical density values from the 1979 aerial photographs failed to provide consistent results to permit the identification of variations in soil conditions within areas of ORV activity. The monitoring program was developed as a multistage remote sensing approach. The first stage utilizes large scale (1:4000) aerial photographs to map and measure ORV trails and associated zones of secondary disturbance within a study area. The second stage utilizes very large scale (1:600) aerial photographs to sample the study area and assess the erosion conditions. The third stage collects ground information to assist the aerial photograph interpretation of the first two stages and to provide quantitative measures of the changes to selected soil and vegetation variables. To consolidate the monitoring program information, an ORV impact condition scale was developed. The simple five point scale summarizes the varying impact conditions within a study area and can be used to assess general changes over time within land management units.Forestry, Faculty ofGraduat