TITLE:
Integrated Modeling of Soil Erosion for a Canadian Watershed in Response to Projected Changes in Climate and Consequent Adoption of Mitigating Best Management Practices
AUTHORS:
Robert L. France, Chengxi Zhang, Gordon R. Brewster
KEYWORDS:
Watershed Soil Erosion, Integrated (GIS, RUSLE) Modelling, Climate Change, Buffer Strips
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.6 No.6,
June
15,
2018
ABSTRACT: 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.