Featured Stories

The Value of GIS and Ecological Risk Assessment Framework

By: Ted Wickwire, Senior Environmental Scientist, Team Leader, and Joe Famely, Environmental Scientist, GIS Manager, Applied Ecology & Sustainability, Woods Hole Group

As evidence of climate change impacts on coastal communities mounts, risk managers and coastal engineers apply models to assess potential impacted areas and identify assets at risk (Bosma, 2016). Traditionally, infrastructure assets (e.g., buildings and roads) are of greatest concern and the consequence of inundation is most readily determined based on engineering criteria (e.g., critical elevations).

In contrast, ecological assets are given less consideration, in part, because the impacts are more difficult to identify and valuing ecological assets is less clear. Increasingly, it is important to understand the vulnerabilities of ecological and recreational assets such as wetlands, beaches, endangered species habitats, and natural resource recreation areas (e.g., trails, viewsheds). Bosma (2016) presents a detailed summary of the sophisticated sea level rise and storm surge dynamic models that calculate coastal inundation probability over a range of sea level rise scenarios and planning horizons. These model outputs provide a starting point for evaluating ecological asset vulnerabilities. Once the probability of excess water occurring in unexpected locations is modeled, the implication of ecological impacts is determined. A systematic approach to the assessment ensures that uncertainties are accounted for, data needs are met, and the resources are protected.

Figure 1. Vulnerability workflow - Spatial inventories of assets (used to develop asset scores) and modeled inundation probabilities. The asset scores are combined with the inundation probabilities to develop asset-specific risks indices.

Figure 1. Vulnerability workflow - Spatial inventories of assets (used to develop asset scores) and modeled inundation probabilities. The asset scores are combined with the inundation probabilities to develop asset-specific risks indices.

Prioritizing ecological assets to focus adaptation actions requires spatially explicit storm surge/sea level rise probabilities, flood depths and duration, and the consequence of water covering each asset. There are two powerful analytical tools available for these analyses:

  • Geographic Information Systems (GIS): An integral tool for the display and analysis of the intersecting climate modeling outputs and the ecological assets; and

  • Ecological Risk Assessment (ERA) Framework: Provides the foundation for assessing impacts and comparing the relative value of different ecological assets.

Geographic Information Systems

GIS provides a visual summary of where different magnitudes of inundation will occur, including protected ecological resources. As a planning, communication, assessment, and management tool, GIS occupies a central position in the process translating the vulnerability modeling outputs into decision points for risk managers. GIS provides two primary visual summaries. First, map layers provide detailed characterization of coastal areas with respect to ecological features such as habitat types, endangered species nesting areas, and recreational areas (e.g., beaches, picnicking areas, trails). Map layers are widely available from state and federal agencies, municipal governments, non-profit land managers, ArcGIS data libraries, and universities. In some cases, asset maps may need to be created for specific areas and unique assets. GIS spatial functions can provide important details such as the area of each asset, elevation, connection to other assets, and slopes.

Second, inundation predictions from models are translated into map layers. Overlaying the vulnerability mapping outputs with the ecological and recreational asset data highlights assets most vulnerable to storm inundation and sea level rise. Different inundation scenarios can be mapped directly for each asset. The depth and duration of inundation at different locations in a study area can be estimated from these maps.

The Value of GIS and Ecological Risk Assessment Framework for Analyzing Climate Vulnerability of Ecological Assets 1

GIS provides a visual summary of the spatial distribution of assets, inundation probability, and the vulnerability risk index for each asset (Figure 1) and can be used to calculate spatial statistics to summarize impacts in greater detail. GIS can also be used to evaluate adaptation scenarios. The next step is determining the consequence of inundation.

Ecological Risk Assessment Framework

The ERA Framework was originally developed to evaluate the influence of chemicals in the environment, focusing on potential exposures and effects to plants and animals (and ecosystems). Importantly, the ERA Framework can also add value and structure to climate vulnerability assessments (Figure 2)—in this case, vulnerability and risk are interchangeable. The problem formulation step is used to gather data, ask the key risk questions, and structure how the questions will be answered. In the case of climate vulnerability, questions include:

  • What is the probability that an ecological resource will be inundated in 2070?

  • What is the depth of the water (and duration of inundation) in 2070 for a given resource?

  • What is the potential influence of inundation (e.g., loss of use for inundation period, total loss of asset, or injury)?

  • Does the loss matter? What is the value of the asset?

The problem formulation under a climate vulnerability assessment includes activities such as cataloging the uses of an asset. For example, a beach might provide nesting habitat for 10 piping plover pairs. In comparison, another beach might not provide habitat for the plover, but does provide a barrier between the ocean and a brackish wetland. The uses of an ecological asset are then evaluated in terms of the value of the asset, including, recreational, ecological, and economic values. The problem formulation also includes a history of change and regulatory requirements for each asset, if applicable.

Figure 2. The Ecological Risk Assessment Framework (Adapted from EPA, 1998).

Figure 2. The Ecological Risk Assessment Framework (Adapted from EPA, 1998).

Once the background data are collected and the vulnerability/risk questions framed, the next step in the process is determining the probability of exposure, in this case inundation. The probability of inundation in 2070 might be 0.5% for one asset, while another asset might have a probability of inundation of 50%. The depths and duration might vary as well.

With an understanding of the probability of inundation from the exposure assessment, the analyst moves to an effects assessment. In this step, the analyst determines the consequence of the inundation. While infrastructure might have a critical elevation above which an asset is destroyed, assessing the consequence of inundation to ecological resources requires a more nuanced evaluation. The ERA Framework effects assessment relies on an assessment of lines of evidence. Lines of evidence are measures that reflect the health of an ecological asset; these lines might include an assessment of species-specific sensitivities (e.g., to seawater) within a habitat type, consideration of the population size and potential loss of wildlife, literature studies on non-chemical stressors, and direct observations by experts on the ecological resource. Some exposures may not lead to an impact, while others, however small, might destroy an asset.

Table 1. Example of Effects/Consequence Scoring Table for an Asset. Total possible score = 4 characteristics x possible maximum score of 5 = 20. Asset specific consequence score = 13/20 = 0.65.

Table 1. Example of Effects/Consequence Scoring Table for an Asset. Total possible score = 4 characteristics x possible maximum score of 5 = 20. Asset specific consequence score = 13/20 = 0.65.

During the problem formulation, the different values of an asset were defined; in the effects analysis, values are quantified. Traditionally, a rating system is applied to the different characteristics of an asset describing the impact of inundation on the value of each asset (low consequence = 1, high consequence = 5). Asset scoring characteristics include, for example, impact on access, impacts on use, impact to sensitive wildlife/plants, scale of impact, and economic impact. For each asset, these characteristics are scored (see Table 1).

Ultimately, the probability of inundation (exposure) is multiplied by the consequence score (effect) to arrive at an overall risk or vulnerability to the specific asset. The risk scores for one asset are compared to the scores from other assets to rank the assets in terms of overall vulnerability. Two other important steps in the risk framework include communicating the risk to the community and managing the risk. In this case, risk management focuses on implementing adaptation and resilience projects for the most valued assets with the highest probability of inundation.

Conclusion

Assessing climate vulnerability to ecological assets relies on the same dynamic storm surge models applied to infrastructure assessment. Determining the consequence of different inundation scenarios to ecological assets requires different tools. Both GIS and the ERA Framework are key tools used to integrate the climate inundation dynamic modeling outputs into a determination of risk. Both also add value to the development and implementation of adaptation and resilience plans for ecological assets. They provide effective and transparent pathways to calculating, communicating, and managing climate vulnerabilities.

References

Bosma, K. 2016. Climate Change Prioritization: Cost-effectively building resilience using high resolution modeling. ECO. September, 2016.

Environmental Protection Agency (EPA). 1998. Guidelines for Ecological Risk Assessment. Washington, DC: US Environmental Protection Agency, Risk Assessment Forum. EPA/630/R-95/002F. April 1998.

Latest Issue

Image
The Blue Carbon Story

The Blue Carbon Story

By Kerrylee Rogers and Neil Saintilan

How to Protect the Bering Strait

How to Protect the Bering Strait

By Elena Agarkova Belov and Alexander Moiseev

Our Partners

Frontiers in Marine Science
American Academy of Underwater Sciences
UNESCO

ECO Magazine is a marine science publication committed to bringing scientists and professionals the latest ground-breaking research, industry news, and job opportunities from around the world.

Newsletter Signup

Please type your full name.

Please type your full name.

Invalid email address.

All emails include an unsubscribe link. You may opt-out at any time. Clicking subscribe confirms your acceptance of our privacy policy.