Flooding is a serious form of natural hazard in Alaska, USA. Two of Alaska’s biggest cities, Anchorage and Fairbanks, have experienced flooding of varying magnitude since the cities were first settled in the early 20th century. Although flood mitigation measures such as blue-green infrastructure (BGI) are rising in prominence, the spatial relationship of BGI, urban pluvial flood (UPF) zone, and social vulnerability remains understudied. This study delineates the UPF zone of Anchorage and Fairbanks using the Blue Spot modeling and correlates it with the distribution of BGI at Census Block Group (CBG) scale, focusing on underlying social vulnerability using a set of indicators. Anchorage shows a positive correlation (r = 0.53, p < 0.01) between percentage of UPF area and density of BGF, whereas Fairbanks shows an insignificant negative correlation. In Anchorage, more socially vulnerable CBGs (n = 10) intersect with high blue spot CBGs (n = 33), compared to Fairbanks where those numbers are 1:6. The results indicate that while BGI is equitably and proportionally distributed within the Anchorage UPF zone, the same is not true in Fairbanks, where distribution is equitable, but not proportionate to pluvial flood risk. The study emphasizes that both types of distribution present their unique challenges and opportunities, but the relative absence of BGI increases flood risk for residents. The results are useful for spatial planners to better inform flood mitigation strategies in urban areas, especially to reduce the gap between equitable and proportional distribution of BGI.
Pallathadka, Arun K.; Chang, Heejun; and Ajibade, Idowu
"The Spatial Patterns of Pluvial Flood Risk, Blue-Green Infrastructure, and Social Vulnerability: A Case Study from Two Alaskan Cities,"
International Journal of Geospatial and Environmental Research: Vol. 8:
3, Article 2.
Available at: https://dc.uwm.edu/ijger/vol8/iss3/2