Dear editor:
With severe weather events predicted to increase, 2013’s devastating flood may be one of several to occur in our lifetime.
Forests act as sponges in the hydrological cycle, storing water and slowing its release. However, extensive clearcut logging, approved by Alberta Environment and Sustainable Resource Development (ESRD) and practiced in both the Elbow and the upper Bow Basin watersheds, leaves the landscape compromised in its capacity to store water. Lack of forest coverage leads to greater snow accumulations and accelerated spring melting, which, in turn, leads to increases in run-off rates and deposition of sediments in our rivers and reservoirs.
At present, it could be argued that ESRD and Spray Lake Sawmills have not done due diligence in simulating the effects of severe weather on water volumes in the upper Bow Basin. Why? ESRD and Spray Lake Sawmills continue to use the equivalent clearcut area hydrological model (ECA) to plan timber harvests. This ECA hydrological model cannot simulate “peak instantaneous discharge,” i.e. flood events. The ECA model cannot simulate “mass-energy transfer,” i.e. rain-on-snow events. And, the ECA model cannot simulate infiltration, i.e. precipitation on frozen or already-saturated soils.
As extreme weather events – both drought and flood – become the norm, we must abandon land use practices with the potential to magnify extreme weather events, and this includes clearcut logging.
Andreas Schneider
