Community risk assessment of flooding and heat hazards available for Baltimore

Chesapeake communities are at a heightened and increasing risk for flooding and coastal hazards. Impacts from these hazards are unevenly distributed across the country due to differences in topography, risk profiles, and local influences. NCCOS and partners have published a report and story map for a new assessment highlighting where communities in the Baltimore metropolitan area are most at risk from flooding and urban heat. Findings from the study will allow communities to better assess and document their risks from environmental hazards.

The research team first met with partners and community managers to discuss the research needs of the region and establish how a risk assessment could best support existing research and management efforts. For this assessment, five components of risk were prioritized: population projections, structural exposure including critical infrastructure, ecosystem service valuation, flooding hazard, and urban heat hazard. Flood risk was further broken down into three categories: stormwater flooding, sea level rise, and storm surge. 

The science team created maps for each of these components, and then layered them together to identify the geographic areas where hazards and vulnerabilities overlap, highlighting which communities are at increased risk. By analyzing the combined maps for co-occurrence, the study found that: 

• Stormwater flooding poses a threat not only through destructive flows but also in areas where water accumulates.
• Urban heat is a critical issue in the study area, driven by the concentration of impervious, heat-absorbing surfaces, such as asphalt and concrete, and limited tree cover and green space. 
• Given the historic nature of both Baltimore and Annapolis, a large proportion of commercial and cultural landmarks are located along the waterfront, placing them in the risk zone for sea level rise and storm surge. 
• More detailed combinations were used to explore the potential for nature-based infrastructure to protect key community resources.

This assessment was conducted in collaboration with Maryland Sea Grant, the Maryland Department of Natural Resources, NOAA’s Office for Coastal Management and the Baltimore Urban Waters Partnership. The research aligns with the Coastal Zone Management Act by providing scientific data to help ensure sustainable and resilient coastal zones.