Coastal Bluff Recession Mapping in Southeastern Wisconsin: Data and Insights for Coastal Resilience

Session: Coastal Resilience in the Face of Change (1)

Adam Bechle, Wisconsin Sea Grant, [email protected]
Chin Wu, University of Wisconsin - Madison, [email protected]
Nicholas Jordan, FreshWater Engineering, [email protected]
Boyuan Lu, University of Wisconsin-Madison, [email protected]
Prakriti Khanal, 1996, [email protected]
Isak Fruchtman, University of Wisconsin - Madison, [email protected]

Abstract

Coastal bluff recession is a constant hazard along southeastern Wisconsin’s shoreline, posing risks to property and infrastructure. Southeastern Wisconsin’s Lake Michigan coastal bluffs vary from urbanized low bluffs in the south (Kenosha and Racine Counties) to relatively high bluffs to the north that are both developed (Milwaukee County) and undeveloped (Ozaukee County). Over time, these bluffs recede in response to a combination of environmental stressors like wave impact, water level fluctuations, and groundwater flow, as well as anthropogenic modification of the littoral sediment supply and nearshore conditions. In this talk, bluff crest and bluff toe recession was mapped from historic aerial photos in southeastern Wisconsin for both recent (1995-2015) and historical (1956-2015) periods. Environmental conditions and anthropogenic modifications of the coast over the analysis period will be characterized and related to bluff recession rate. The results of this study will provide data to aid planning and decision making, as well as insights into the conditions and actions which affect bluff recession. This study is part of a NOAA Coastal Resilience Grants project to provide hazard data, educational resources, and technical assistance to Southeastern Wisconsin coastal communities in a coordinated effort to build resilience to coastal hazards.