From 2004 to 2010, Hemmera conducted detailed scientific analyses of many impacts on the landscape that can be expected in the future, as climate change causes more frequent, more intense storms. The objective was to predict landslide and other events, and to use these predictions in land-use planning and other mitigation strategies.
These detailed studies involved sophisticated climate change modelling of locations on the Pacific Northwest coast. Hemmera researchers analyzed data obtained from mesoscale numerical weather modeling, landslide inventories, and innovative change detection mapping. This data was used to quantify the relationships between landslides and the intensity of rainfall, air temperature and wind speed. We examined the role of windblown trees, in terms of the loss of the forest resource, and a causal factor in landslides and flooding. Further, we examined the role of storms, and the frequency of storms, in the planning of storm water management and road design.
The study identified the critical onset of rainfall intensities that result in a rapid increase in landslide occurrence. It also quantified the role played by high winds, as rain and snow that is driven by high winds accelerates rain-on-snow melting. It also identified the direct role of windblown trees. The critical role of wind is an often-neglected component of hydrological analyses which increases the challenge to land-management strategies, and can change where, and when snow zones will melt in a warming climate.
Our work resulted in adaptation strategies, which include rainfall shutdown guidelines for industry and improved planning of resource developments, road layouts and stream crossings, which will mitigate the damage from landslides.
