摘要
Controlling soil erosion and the transport and deposition of suspended sediment to receiving waters, especially in relation to the modifying influences of, and interplay between, climate and land-use alterations, is essential for effective watershed management. The Atlantic Canada—New England region is expected to experience elevated rainfall erosivity due to climate change over the next century. Using the projected higher precipitation amounts of 5% and 10% for future scenarios of 5 and 25 years for the region, and a spatially-explicit, integrated (GIS, RUSLE) model for a rural watershed in Nova Scotia, predicted increases in total erosion rates of 4.9 and 9.9%, respectively. Modelled scenarios altering buffer strips based on either consistent or slope-variable widths between 30 m (the legal requirement) to 90 m were found to correspond to reductions in predicted total watershed erosion rates from 11% to 32%. Assuming and extending the 1:1 concordance between projected precipitation and estimated soil erosion for this particular watershed into the more distant future of 26 to 55 years, suggests that the 25% increase in soil erosion predicted over this period would have to be offset by expanding the protective buffer strips to a consistent width of 70 m. Adoption of such a protective management scheme would subsume 19% of the terrestrial area of the study watershed and thus consequent reductions in land available for agricultural production and timber harvest.
Controlling soil erosion and the transport and deposition of suspended sediment to receiving waters, especially in relation to the modifying influences of, and interplay between, climate and land-use alterations, is essential for effective watershed management. The Atlantic Canada—New England region is expected to experience elevated rainfall erosivity due to climate change over the next century. Using the projected higher precipitation amounts of 5% and 10% for future scenarios of 5 and 25 years for the region, and a spatially-explicit, integrated (GIS, RUSLE) model for a rural watershed in Nova Scotia, predicted increases in total erosion rates of 4.9 and 9.9%, respectively. Modelled scenarios altering buffer strips based on either consistent or slope-variable widths between 30 m (the legal requirement) to 90 m were found to correspond to reductions in predicted total watershed erosion rates from 11% to 32%. Assuming and extending the 1:1 concordance between projected precipitation and estimated soil erosion for this particular watershed into the more distant future of 26 to 55 years, suggests that the 25% increase in soil erosion predicted over this period would have to be offset by expanding the protective buffer strips to a consistent width of 70 m. Adoption of such a protective management scheme would subsume 19% of the terrestrial area of the study watershed and thus consequent reductions in land available for agricultural production and timber harvest.
