USE OF LIDAR, RADARSAT AND WORLDVIEW-2 DATA TO ASSESS SURFACE WATER RETENTION AND SOIL MOISTURE IN POORLY DRAINED PRAIRIE FIELDS

Hundreds of square kilometers of farmland on low-relief glaciolacustrian clays in southern Manitoba are affected annually by short-term ponding of direct runoff from snowmelt, and frequently by secondary flooding when discharge in rivers exceeds channel capacity. In this study, remote sensing data, including high resolution LiDAR, RADARSAT from several years, and an 8 band bundle capture from WorldView-2 are used to analyze surface water flow and transient retention in part of a typical watershed, the La Salle River basin southwest of Winnipeg, Manitoba. Areas contributing water to local depressions are estimated using LiDAR data, including LAS datasets and DEMs. The capacity of fields to retain direct snow melt runoff and/or river floodplain inundation without surface water overspill is evaluated. Natural depressions are described by area, elevation and volume. Remote sensing products are used to assess whether the size, depth and location of natural surface water ponds are consistent year to year. A Wetland DEM Ponding model analysis is compared against observations from remote sensing data analyses.