Wind Erosion Risk and Climate Sensitivity

View this map

---

Abstract

Wind erosion risk for unprotected soils in areas sensitive to climatic change is shown here. The regions that would have the highest sensitivity to a warming climate are likely to occur in the southern and central Prairies and in the southernmost part of Ontario. This risk of wind erosion is based on the nature of local climate and vegetation. Areas with dryer, warmer climates and with sparse vegetation cover are more vulnerable to wind erosion. The levels of climate sensitivity were derived by comparing present and future ecoclimatic regions of Canada, based on the assumption of a doubling of atmospheric carbon dioxide concentrations over pre-industrial levels.

---

The Theme

Wind erosion has noticeable effects on agricultural lands and on sand dune areas in many parts of Canada. These effects result in soil and nutrient losses and, ultimately, in reduced crop yields. A relatively good understanding exists of wind erosion impacts on these unprotected soils under present-day conditions. In general, the risk is increased when soils are dryer and winds are stronger. Both of these conditions are more likely to occur as the climate warms. This map shows the projected vulnerability of these areas to climate change.

Sensitivity Projection

This map shows both the projected general patterns and the local details of these patterns. Two variables are being mapped:

• Wind erosion risk. This risk is based on the nature of local climate and vegetation. Areas with dryer, warmer climates and with sparse vegetation cover are more vulnerable to wind erosion. The degree of wind erosion risk is shown on the map by using heavier saturation of any of the colours (in other words, dark colour shades of any colour mean a higher wind erosion risk).
• Climate sensitivity. The levels of climate sensitivity were derived by comparing present and future ecoclimatic regions of Canada, based on the assumption of a doubling of atmospheric carbon dioxide concentrations over pre-industrial levels. The projection of future ecoclimatic regions of Canada was developed by Rizzo and Wiken (1992). The sensitivity results are shown by types of colour. Areas in bright colour will have a more substantial shift of their ecoclimatic region type if the projected carbon dioxide change takes place. For example, the projected shifts are more pronounced in the southern Prairies and in the southernmost part of Ontario.

Each of the two variables is divided into four categories to suggest the severity of risk. The matrix of sixteen possible combinations of these two valuables is mapped below (Figure 1). Areas of greatest risk are represented using the most vivid colours, as well as the heaviest saturation of each colour.

[D]
Click for larger version, 19 KB
Figure 1. Sensitivity Matrix

Risk Patterns

The map reveals that the regions that would have the highest sensitivity to a warming climate, as shown in pink and orange, are likely to occur in the southern and central Prairies and in the southernmost part of Ontario. Within these regions, there is a varying degree of vulnerability to wind erosion risk, depending on local circumstances. Areas with lowest overall risk are likely those shown in light green, which have a lower climate sensitivity as well as a lower level of wind erosion risk under the present-day conditions. These areas are found in the northern fringes of the Prairies and in large parts of the agricultural areas of Quebec and the Maritimes.

Dune sensitivity was also derived based on the potential change in ecoclimatic conditions. Changes in wind erosion risk of sand dunes will mainly result from changes in the amount and type of vegetation cover. Most sand dunes in Canada are rated as having a low climatic sensitivity because the changes in vegetation cover are found to have minimal effects on most sand dune activity. The areas that are sensitive to climate change include the southern portions of Alberta and Saskatchewan corresponding to a potential semi-desert ecoclimatic region. Southern Ontario and portions of the Maritimes, including Prince Edward Island, have moderate to high sensitivity. Sensitivity declines northward with changes in climatic and vegetation conditions.

Data Source

This map is an insert to the publication: Wolfe, S.A. and W.G. Nickling. 1997. Sensitivity of Eolian Processes to Climate Change in Canada. Geological Survey of Canada Bulletin 421. Ottawa: Natural Resources Canada.