An Integrated Modeling Framework for Analyzing Wetlands Policies

EPA Grant Number: R827932
Title: An Integrated Modeling Framework for Analyzing Wetlands Policies
Investigators: Weinberg, Marca , Quinn, James
Current Investigators: Wilen, James , Quinn, James , Newbold, Stephen
Institution: University of California - Davis
EPA Project Officer: Chung, Serena
Project Period: October 1, 1999 through September 30, 2002
Project Amount: $125,000
RFA: Decision-Making and Valuation for Environmental Policy (1999) RFA Text |  Recipients Lists
Research Category: Environmental Justice


The purpose of this project is to create and operationalize a modeling framework that incorporates both the potential environmental benefits and the expected economic costs of various wetlands management strategies for purposes of comparative policy analysis. Three classes of wetland ecosystem services will be incorporated into the framework: water quality enhancement, habitat for wildlife, and flood management benefits. The framework will be specifically designed to assess the cumulative impacts of multiple management decisions on various environmental objectives at the landscape scale. The methods will be applied to the San Francisco Bay-Delta region and associated watersheds in California's Central Valley.

This research is motivated by two general working hypotheses. First, wetlands are often cited as being able to provide a veritable laundry list of environmental benefits ? surface water quality enhancement, flood management benefits, habitat for wildlife, recreational opportunities, aesthetic values and more. However, these benefits will be only somewhat complimentary, depending on the site-specific attributes of the wetland system in question, as well as the landscape context in which it is located. Not all wetlands will provide all of these possible ecosystem services equally. Therefore, making wetland management decisions based on one or a subset of these environmental benefits may lead to significantly different results than a strategy based on another subset of these environmental benefits. Second, these ecosystem services will be influenced by their landscape context, e.g., which other land use types a given wetland is adjacent to, its distance from other surface water bodies and other wetlands, and the degree of fragmentation of different land use types. Since management decisions at other sites will change the landscape context for a given wetland patch, the benefits of managing at any given site will depend on management decisions elsewhere in the landscape. Thus, a management strategy that considers the entire landscape simultaneously likely will be more effective than a strategy that considers potential management sites on a case-by-case basis.

The objectives of the project are to investigate these hypotheses, with an empirical application to the San Francisco Bay-Delta and Central Valley regions of California. First, we will determine just how important landscape considerations are for the ecosystem services in question. Then, based on these estimated relationships, we will investigate the management or policy significance of these landscape-level interdependencies, as well as the complexities in decision-making that arise when the multi-objective nature of these wetlands management scenarios are explicitly accounted for.

To date, most research in this area has focused exclusively on one aspect of the general wetlands policy problem described here. Much research by ecologists and other natural scientists has shed light on the functions and processes within wetlands and across landscapes that lead to the provision of valuable ecosystem services from wetlands. Recent research by economists and others has begun to elucidate the complexities that arise from spatial interdependencies when making decisions on a landscape scale. However, the former area of research stops well short of investigating the full policy implications of the potential environmental benefits from wetlands. Also, the latter area of research is in its formative stages, and has generally only been applied at very course spatial scales (i.e. county-level resolution), and certainly has not been applied to questions regarding wetlands policy.


The project will proceed in two phases. In the first phase we will utilize statistical and numerical process modeling techniques to estimate the relationships between wetlands and other land use types and the provision of three classes of ecosystem services: water quality enhancement, habitat for certain species of wildlife, and flood management benefits. The water quality and habitat functions will be estimated by statistically associating land-use data derived from a GIS to data on indicators of each of these two ecosystem services ? measures of the concentration of nutrients and pollutants in surface waters, and measures of occurrence and abundance of wetland bird species in the study area, respectively. The flood management benefits will be estimated using a large-scale hydrologic process model integrated with a GIS. This will allow us to estimate the expected changes in flood-stage at various points in the watershed likely to result from changes in land use, especially conversion and restoration of wetlands in the floodplain. Meta-modeling of process model output will be performed as necessary to summarize the relationships between wetland extent and location on the propensity of flooding in the study area.

The second phase of the project will incorporate the functions estimated in the first phase into a spatial optimization model that will allow comparisons of the expected environmental impacts and economic costs of various wetland management strategies. Numerical optimization models will simulate a hypothetical decision-maker who is interested in maximizing the environmental benefits of wetland management projects, subject to a budget constraint. By varying the form of the objective function and the specification of the constraints, the model will result in different configurations of "optimal" wetlands conservation and restoration decisions.

Expected Results:

This project is specifically designed to assess the cost effectiveness of various wetlands management strategies. In addition to simulating optimal management decisions, which will provide informative bounds on wetlands policy benefits and costs, the methods developed here will also be useful for estimating the cost effectiveness of current or proposed management actions. When compared to the simulated optimal management strategies, decision makers can assess the performance of actual current, recent, or proposed management decisions. Therefore, this framework can be used to improve the ability of EPA, and other agencies involved in wetlands policy, to protect the environment and ensure such enhanced protection is achieved at the lowest possible costs.

The results of this project will also provide insights into the potentially conflicting nature of wetlands policy-making. Since wetlands management decisions, at least in aggregate, are driven by multiple environmental objectives, there will necessarily be unavoidable tradeoffs associated with these decisions (environment-environment tradeoffs as well as environment-economy tradeoffs). This research will illustrate precisely how conflicting or complimentary these different objectives--water quality, habitat, and flood management--are likely to be, based on various characteristics of the management proposals and the ecological context of the proposed actions. The suite of results from the model runs will allow us to explicitly characterize the various interrelated ecological and economic aspects of wetlands policy-making.

Finally, various government and state agencies are involved in wetlands management, but from somewhat different perspectives. In terms of the framework developed here, EPA might be most interested in the water quality benefits that wetlands can provide, the Army Corps of Engineers might focus on the potential flood management benefits of wetlands, and the U.S. Fish and Wildlife Service might emphasize the habitat values of wetlands. Each of these federal agencies has a role in wetlands policy-making and management, and there may be gains to be had by increasing the degree to which these agencies coordinate their wetlands management efforts. The framework developed in this project will allow us to estimate these potential gains from enhanced coordination between agencies. The methods are applied here to the environmentally-sensitive and high-profile San Francisco Bay/Delta watershed, and thus should provide valuable information and tools for managing this important policy problem. More generally, the methods and results will be informative for national-level wetlands policy as well.

Our results will be disseminated to professional audiences via publication in relevant scientific journals. We foresee articles from this research being submitted to top-quality, peer-reviewed scientific journals in both the social science and the natural science realms. Prospective publication outlets range from the Journal of Environmental Economics and Management and Ecological Economics, to Science, Nature, and Biological Conservation, to more policy-oriented journals such as the Journal of Policy Analysis and Management. In addition, we plan to pursue outlets more accessible to policy makers and stakeholders, including (but not limited to) the Information Center for the Environment (ICE) web page (http:/, which is one of the most active university-based sources of environmental information in the country, regularly receiving 20,000 hits per week, and is already devoted to providing decision support information for EPA Region 9.

Publications and Presentations:

Publications have been submitted on this project: View all 3 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 1 journal articles for this project

Supplemental Keywords:

ecosystem indicators, watersheds, habitat, aquatic, public policy, cost benefit, nonmarket valuation, public good, social science, socioeconomic, RFA, Economic, Social, & Behavioral Science Research Program, Scientific Discipline, Geographic Area, Water, Ecosystem Protection/Environmental Exposure & Risk, Nutrients, Ecosystem/Assessment/Indicators, Ecosystem Protection, State, Ecological Effects - Environmental Exposure & Risk, Environmental Monitoring, Ecological Risk Assessment, Ecology and Ecosystems, decision-making, Ecological Indicators, Economics & Decision Making, policy analysis, remote sensing, wetland policies, wetlands, aquatic ecosystem, ecological exposure, computer simulation model, nutrient sensitive ecosystems, San Francisco, integrated modeling, non-market valuation, socioeconomics, flood management, cost/benefit analysis, aquatic ecosystems, water quality, ecosystem restoration, public policy, California (CA), wetlands preservation, wildlife habitat, land use, social sciences, benefits assessment

Progress and Final Reports:

  • 2000 Progress Report
  • 2001
  • Final Report