Combining Field and Modeling Tools As an Approach to Assess Cumulative Surface Erosion in Alberta Eastern Slopes and Foothills.

Abstract:

Alberta is a large province with diverse forested landscapes and heavy industrial, range and recreation use. Hillslopes are generally stable but the cumulative surface erosion from bare areas (e.g. roads, well pad, trails, burns and pipelines) is a major concern for downstream water users, aquatic ecology and stream habitat. Most streams are not exhibiting issues from additional coarse soil (e.g. obvious changes to geomorphology) however, soils with high proportion of fines and phosphorus have been attributed to long lasting aquatic ecology impacts and associated downstream water quality issues. For this project we take a watershed scale approach to determine if we can reduce field effort by using high quality digital terrain data available for most of Alberta combined with tools such as the Geomorphic Road Analysis and Inventory Package (GRAIP) and landscape scale GIS assessment and modeling tools such as NetMap. We examine two contrasting regions of Alberta: (1) a tributary of the Oldman River in southwest Alberta that has steep topography, intense storms and heavy motorized recreation from the neighboring 1.5 Million people, and (2) the Foothills area that has fine lacustrine soil, low topography and extremely heavy industrial activity from energy, mining and forestry.

We present the initial results of field data combined with GIS analysis for the eastern slopes as part of a larger project that is assessing these tools in represented end member watersheds for forested areas within the foothills and eastern slopes region (area of Alberta where watersheds have meaningful topography). Initial results suggest that GIS and associated modeling are very useful in providing rapid direction for field campaigns to refine the level of uncertainty, make prescriptive field plans and will likely be platforms that can track changes in predicated watershed scale erosion rates through time.