The inspiration for this project is a series of floods that took place in Alaska during the rainy months of April and May in 2009. Above-average temperatures in the spring time began to rapidly melt rivers and large chunks of ice that were released dammed up rivers subsequently. When these ice dams broke, catastrophic flooding ensued. A record-breaking flood of this type occured in Eagle Village in Alaska, with blocks of ice the size of buildings destroying whatever was in its path. There was also heavier that usual snowfall during the winter which allowed the above-average temperatures in the spring to produce substantial amounts of snow melt that fed into rivers. Rivers across Alaska were flooding as a result of the climate in 2009 but the Yukon River was one of the hardest-hit.

For our flood analysis, several factors that may contribute to the occurrence of floods were taken into consideration. In addition to precipitation, topographical factors we included were slope, water accumulation area, presence of wetland, drainage density, land use and soil type. Wetlands act as a flood mediating mechanism due to their water storage capacity, and fewer floods are associated with low drainage densities. Areas with less vegetation and barren ground tend to be at higher risk for flooding because vegetation serves to store water as well as decrease run-off by rainfall interception. Soil that has low permeability to water would also tend to flood because water infiltrates through the soil too slowly and ponds at the surface. This occurs when the infiltration rate is less than the precipitation.

Click here for photos of floods in Alaska.