June 14, 2018By seawa
Riparian areas in Seven Persons Creek Watershed were assessed using a Riparian Health Model (RHM) calibrated to the Cows and Fish ground method of riparian assessment for both streams (lotic) and lakes/reservoirs (lentic). The RHM used existing ortho-based aerial imagery (25-50 cm resolution) and an existing LiDar (Light Detection and Ranging) derived Digital Elevation Model. The overall results (below) show a considerable number of stream riparian areas were rated as ‘unhealthy’.
Results of RHM classification of lotic and lentic systems in the Seven Persons Creek Watershed.
Riparian areas designated as ‘unhealthy’ do not necessarily indicate degradation solely due to human activities. Many of these riparian areas are naturally bare or are vegetated with grasses and small shrubs (snowberry and wild rose) and they cannot support larger woody vegetation or trees due to the semi-arid climate and the predominant landform (coulees) of the watershed. A landscape defined by coulees would have sections of streams with asymmetrical banks, one bank is bounded by a coulee (hill side) and the opposite bank, a floodplain. For example, the photo below is rated as ‘unhealthy’ due to bare ground and high slope, although those familiar with the local landscape know that this is natural.
Photo credit: Stantec Consulting.
Details of the condition of entire lengths of riparian areas of the major creeks (Seven Persons, Ross, Gros Ventre, Peigan, and Bullshead) and reservoirs (Murray, Cavan, and Elkwater) can be found in the full report here.