Proposed SCR Developing a Network to Track Climate Change Impacts on Wisconsin Stream Channels

Purpose

A robust state-wide network of stations recording stream channel geometry characteristics is important to docment changes resulting from climate change. Midwest magnitudes and recurrence frequencies of high-magnitude, extreme rainfalls are increasing with global warming (Solomon et al., 2007; Watson et al., 1998, Angel and Huff, 1997; Karl and Knight, 1998). Even modest changes of climate have been shown to result in relatively large changes in stream flows and flooding characteristics in the upper Midwest (Knox, 1993; 2000). One of the most likely impacts of changes in precipitation through widening or deepening and remobilization of sediment from gullying, bank erosion, and incision. The current predictions are for more frequent intense precipitation events, resulting in channel-forming flows occurring more frequently with an accompanying degradation of aquatic habitat. Previous and ongoing studies have shown that large floods at closely spaced intervals are particularly erosive and have been increasing in frequency across Wisconsin (Peppler, 2006; Knox and Fitzpatrick, 2010)

Objective

Project Justification: Downscaled climate models have predicted future temperatures in Wisconsin with a reasonable degree of confidence, but future precipitation patterns and resulting runoff and stream flows are less certain. Precipitation models indicate that recent precipitation patterns are predictive of future trends, and Wisconsin is likely to receive an increased percentage of precipitation as rainfall with greater spatial and temporal variability (WICCI, 2009). One of the likely impacts of the increased frequency of high‐magnitude precipitation events on stream health is channel and substrate instability, caused by increases in channel size through widening or deepening and remobilization of sediment from gullying, bank erosion, and incision. Aquatic habitat degradation is likely to accompany the increase in channel‐forming flows. The proposed studies will provide insights into channel geometry changes and will provide valuable data to stream restoration practitioners and fisheries biologists.

Outcome

(1)A distributed statewide network of 20 to 30 stream geomorphology monitoring stations linked with USGS National Stream Information System (NSIP) stations representing a range of drainage basin scales within the state’s physiographic regions; (2)A standard methodology for measuring and documenting important geomorphic features of channels that may be altered by climate change including: bankfull channel geometry, channel and floodplain stability (e.g. channel migration and/or incision), channel substrate (e.g. particle size and bed forms), and stream plan form (e.g. sinuosity and gradient). (3)A professional workshop for training UW System and agency collaborators on the deployment of the standard methodology at the monitoring stations on a recurring basis. (4)An online publicly accessible repository for the stream channel monitoring data to allow analysis by scientists with varying degrees of connection to the field research. (5)Training for UW System undergraduate and graduate students in monitoring geomorphic changes to fluvial systems using field surveying techniques, Geographic Information Systems (GIS) and hydraulic modeling (e.g. HEC-RAS), and laboratory physical analyses; (6)A USGS Water Resources publication describing the established monitoring network and methodology made publically available via the internet. In addition to developing the methodology report, a website will be developed that includes tutorials for individuals seeking to establish a similar monitoring plan at universities and high schools throughout the world. Ultimately the proposed project will enable state-wide documentation of the complex linkages between stream geomorphology and changing hydroclimatic regimes. This database will lead to more accurate modeling of climate change impacts on stream systems while providing resource managers valuable information as they continue restoration activities in what is projected to be an increasingly dynamic hydrologic system.

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Targeted Monitoring
Newly Proposed
SCR_07_CMP12
2011
Inactive