Planning for Extremes: Addressing Climate Change Impact on Soil and Water Conservation
This report was the result of a broader research project that undertook the following:
- Compiled analyses and more extensive data on rainfall and rainfall rate trends and projections in the Canadian part of the Great Lakes basin.
- With soil scientists and erosion specialists estimated erosion rate implications in various parts of the Canadian Great Lakes basin and estimated contaminant transport to groundwater and surface waters.
- Undertook review of erosion control policies and practices and standard design criteria used in Ontario and their current adequacy. In many cases US Department of Agriculture procedures are also used in Canada.
- Review Ontario manure management guidelines as related to animal species and related pathogen risks to assess adequacy in light of more frequent high intensity rains.
Analysis of precipitation from weather stations suggests that intensities of short weather events and frequency of these intense rainfall events have increased over the passed few decades. The research found a shift to heavy rainfall events earlier in the season especially May. Implications of these precipitation changes suggest spring rain and severe summer storm can be most significant. About 85% of annual in-field soil erosion occurs in spring and summer. These trends are expected to continue unless erosion prevention measures are undertaken in the Great Lakes Basin.
These trends also impact water quality. Water quality implications in the Great Lakes and its major tributaries are impacted by chemicals (phosphorous, pesticides, trace metals, bacteria), that are released with the sediment. Increased erosion also impact the benthic invertebrate population by destroying natural habitat.
The Canadian and USA chapters of the Soil and Water Conservation Society worked to collaborate in a transboundary effort to understand increasingly extreme rainfalls on soil in the Great Lakes Basin and make joint recommendations to the USEPA and Environment Canada.
For the full report, see: www.swcs.org/documents/Planning_for_Extremes.pdf.