Climate change is quickly becoming a concern for many organizations, particularly for those in the public sector like cities, counties, states, and watershed districts. The effects of climate change include more frequent extreme precipitation events, warmer winters, increased heat and humidity, and droughts—hazards that directly impact the people these municipalities and watershed organizations serve. Top of mind for these organizations is identifying where climate change hazards are most likely to occur, which groups of people are most at risk, and where those people live.
Although climate change is a complex and multifaceted issue, geographic information system (GIS) mapping has proven useful in analyzing climate change risks and helping organizations begin the planning process to ultimately lessen the negative impacts on people and natural resources.
Conducting a climate change vulnerability assessment
A climate change vulnerability assessment (CCVA) is an emerging tool that serves as the first step in the adaptation planning process by identifying the greatest risks from climate change. Barr recently completed a CCVA for Hennepin County, which includes Minneapolis, the largest city in Minnesota, and its densely populated suburbs. The county wanted to learn how the changing climate might affect water resources, infrastructure, and natural systems, as well as the potential risks to public health, services, and the built environment.
Identifying vulnerable populations
The first task involved identifying population vulnerability in Hennepin County. While everyone is vulnerable to climate change, underlying disparities mean some populations are more sensitive to its impacts and have fewer resources to respond or adapt. Certain factors, such as health, socioeconomics, and race, play a role in which populations have a greater risk of experiencing the negative consequences of climate change.
Demographic and economic data from the U.S. Census Bureau is used to reliably identify and map population vulnerability. For Hennepin County, Barr identified 14 variables that highlight vulnerability, ranging from median household income and population age to English-language proficiency and asthma hospitalization rates. We mapped variables at the census-tract level and classified them into five natural groupings, which were assigned a subsequent score. When scores were assigned to all variables, the variables were added together to create a composite population vulnerability map. Areas with the highest scores represented populations most vulnerable to climate change.
Overlaying the data
A composite population vulnerability map can be used as a tool to prioritize climate change response actions but, in this case, it was used as input for further study. Overlaying the most vulnerable areas with hazards, such as flood susceptibility and air pollution, allowed for more impactful analysis. For example, displaying population vulnerability alongside summer daytime and nighttime temperatures showed that those most at risk live in warmer areas. We inferred that people in these areas, especially those with underlying health conditions or no access to air conditioning, may be more vulnerable to heat-induced stresses.
Barr leveraged GIS open-source data from a variety of government agencies, as well as our own GIS data from previous projects, to show how climate change might impact Hennepin County. We used FEMA floodplain and localized flood risk data from the Metropolitan Council (the regional government agency and planning organization for the Twin Cities area) to highlight facilities, roads, and sidewalks that are vulnerable to extreme precipitation events. We also employed the Minnesota Department of Natural Resources’ Metro Conservation Corridors and the U.S. Geological Survey’s land cover data to illustrate where natural resources are most at risk. Thermal load clusters, developed by Barr as part of a study with the Minnesota Department of Commerce, were overlaid with population vulnerability and facility data to showcase opportunities for district-scale heating and cooling.
The CCVA equipped Hennepin County with data-based information to build a more climate change resilient future for its people and infrastructure. The assessment serves as a foundation and technical reference for the Hennepin County Climate Action Plan, allowing county work groups to present strategies, initiatives, and actions aimed at building resilience to the risks posed by climate change.
Climate change’s far-reaching impact
Using GIS to study the effects of climate change allows us to tailor our analysis to the needs of our clients. While climate change planning is rapidly becoming a high priority for those in the public sector, it should also be on the radar for private organizations as climate change concerns are far-reaching. For example, with increased precipitation events comes a greater risk of flash flooding and erosion, leading to exposed pipelines or washed away power lines—impacting utility operators in the private sector. Using methodology similar to Hennepin County’s CCVA, we can guide our private sector clients in planning and developing strategies for climate change resiliency, and long-term success. Whether you work in the public or private sector, Barr’s climate change scientists and GIS specialists are here to help. Contact us to learn more about Barr's approach to planning for climate change impacts.
About the author
Eddie Anderson is a GIS specialist who has experience with GIS mapping on projects involving climate change vulnerability assessments, including for Hennepin County. He has provided GIS services for more than six watersheds, surface water management, and natural resource management plans.