Susceptibility of Geologic Deposits to Erosion in the House Mountain Area, Alberta

Oil and gas exploration and development in the House Mountain and Swan Hills areas of Alberta has contributed to extensive erosion of the geologic deposits.

Many factors, such as geologic materials, slope, vegetative cover, soil type, groundwater conditions, time, and climate affect the processes of erosion.

Air photograph interpretations and field investigations were utilized in mapping the surficial deposits and assessing their susceptibility to erosion. The erosion susceptibility rating of the materials (from least erodible to most erodible) is as follows: muskeg, gravel, coarse sand, till, clay, shale, fine sand, silt and sandstone.

The map of surficial deposits and their erosion susceptibility rating may be used as an aid in formulating land use plans for the area; however, on-site inspections are recommended wherever development occurs in order to assess the erosion hazards of that particular site.

Methods that can be used to prevent or control erosion include: 1)cutting slopes to as low an angle as possible and disturbing as little surface area as possible; 2)avoiding areas of highly erodible material where possible; 3)leaving protective root and topsoil cover on the ground during logging operations and seismic activities; 4)spreading a layer of roots and topsoil cover on exposed slopes; 5)laying trees, preferably conifers with numerous branches, on exposed slopes to minimize gullying; 6)constructing gravel or boulder berms at regular intervals in ditches or on slopes; 7)avoiding practices which alter the base level of erosion; 8)avoiding terracing of shale and mudstone slopes which results in increased erosion.

If these techniques for prevention or control of erosion are applied in the early stages of any development, erosion problems will be minimized.

It is important that the type of geologic material at each site be recognized as well as the interrelated factors affecting erosion, so that suitable measures can be taken to prevent or inhibit erosion.

Further studies are warranted to provide specific data on the engineering properties, physical properties and chemical composition of the geologic deposits. This information would be of considerable value in assessing further the factors affecting erosion in the area.