Author: Matthew A Smith,  Ph.D. Candidate (Florida International University)

Designation: 

Description:
Climate-driven changes in flow frequency and magnitude directly impact urban ecosystems worldwide. Shifts in regional precipitation interact with heterogeneous urban infrastructure to increase stream discharge variability not explained by river-floodplain hydrology in larger-order rivers and aquatic ecosystems. Increased urban development and stormwater runoff conveyance enhance pulsed hydrologic connectivity that can exacerbate vulnerability – and likely the timing and scale – of climate-related flooding.  We analyzed recent (2000-2020) discharge records from n = 360 watersheds and found discharge in urban streams was less persistent day-to-day but had greater temporal synchrony during annual peak flood events in urban compared to non-urban streams. Flood synchrony scale (i.e., the distance over which multiple rivers flood simultaneously) decreased with urbanization, reflecting smaller drainage areas and increased connectivity in urban watersheds. We merge these ideas into the “flow-shunt flood-pulse concept” (FSFP) to explain and quantify how climate change and urban water infrastructure across different biomes increase and synchronize flooding at smaller scales than in non-urban watersheds of the same geographic distribution. As the frequency and magnitude of storm events shift with climate change, urban water infrastructure and flood management will require mitigation strategies that address how surface water conveyance that “shunts” urban runoff feeds back onto spatiotemporal patterns of flooding that don’t follow watershed boundaries.

Category: Scientific Program Abstract > Special Sessions > SS60 Contextualizing abrupt change using big environmental data at freshwater and marine ecosystems