Photogrammetric estimation of wheel rut dimensions and soil compaction after increasing numbers of forwarder passes

ABSTRACTCompaction and rutting on forest soils are consequences of harvesting operations. The traditional methods used to investigate these consequences are time consuming and unable to represent the entire longitudinal profile for a forest trail. New methods based on photogrammetry have been developed. The overall objective was to compare photogrammetry and traditional methods (e.g. cone penetrometer, manual rut depth measurements, bulk density and porosity) used for the evaluation of soil compaction and rutting (i.e. depth and rut volume) after multiple passes of a loaded forwarder using two different tyre pressure levels. The comparison of photogrammetric versus manually measured profiles resulted in R2 0.93. Both tyre inflation pressure and number of passes had effect on soil disturbance. The rut volumes on 100 m long trails after 60 passes were 8.48 and 5.74 m3 for tire pressures of 300 and 150 kPa, respectively. Increased rut volume correlated positively with increased soil compaction and decreased ...