U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2004-3113 

October 2004

Spatial Decision Support Systems for Landscape Ecological 

Evaluations in the Southwest Florida Feasibility Study

Printed on recycled paper

The objective of the Southwest Florida Feasibility Study 

(SWFFS) is to develop a comprehensive and ecologically sound 

regional plan for water resources in southwestern Florida. 

Boundaries of the study are shown in figure 1. The SWFFS 

study area covers about 4,300 square miles, and lies west of 

the Everglades and most Comprehensive Everglades Restoration Plan (CERP) activities. The study was recommended by 

CERP and the Comprehensive Review Study for inclusion in 

the Central and Southern Florida (C&SF) Project because of: 

(1) water-supply and ecological issues with water releases from 

Lake Okeechobee to the Caloosahatchee River, and because 

(2) inland hydrologic alterations have substantial existing and 

potential effects on rich natural resources and biodiversity 

within the study area. This study will address the health of 

upland and aquatic ecosystems and will consider a variety of 

parameters including water flow, water quality, water supply, 

maintenance of existing flood protection, wildlife, biological 

diversity, and natural habitat. The SWFFS is being conducted 

by the U.S. Army Corps of Engineers and the South Florida 

Water Management District. The USGS, in cooperation with 

the University of Florida, is providing technical assistance for 

evaluation of hydrologic impacts to natural systems. 

Landscape level decision-making is a process that involves 

multiple objectives, large data sets, and many unknowns and 

uncertainties. To support this process, evaluation tools are 

needed to make informed long-term regional resource decisions 

and recognize research needs. These tools can help authorities involved in ecological restoration by identifying decision 

variables, developing problem solving heuristics, and evaluating 

the consequences of alternative policy actions. Spatial decision support systems (SDSS) for natural resource management 

are computer-based tools that tightly integrate decision theory 

models with ecological models and Geographic Information 

System (GIS) analyses and mapping. The information provided 

by SDSS gives decision makers increased ability to follow 

outcomes of interacting variables, improves the reproducibility 

of decisions, and documents the reason why (with conflicting 

alternatives) a particular choice was made (Rauscher 1999).

The framework for decision support of landscape habitat 

evaluations has four components (fig. 2). The first two components, primarily intended for use by the scientist, assist in 

assessing which criteria best define performance measures for 

ecological evaluation and which values those criteria will have 

with a particular scenario. The first component is an analysis of 

the proposed scenarios and their respective effects on the physical environment. These analyses are supported by inputs from 

models that simulate each scenario such as hydrologic models, 

urban growth models, and water-quality models. Tools provided 

in the second component evaluate effects on wildlife habitat 

and ecological communities caused by changes in the physical 

Figure 1. The Southwest Florida Feasibility Study 

area (shaded in green) showing major canals.

Figure 2. A hierarchical and modular approach to development 

of a Spatial Decision Support System. Abbreviations represent 

current habitat models in southern and southwestern Florida.
environment. These tools evaluate habitat suitability and risk 

evaluations based on inputs from habitat models. 

The third and fourth components are intended for use, 

respectively, by policy makers and the public. Decision models 

(the third component) rank and aid decisions among criteria and 

alternative scenarios. Evaluations of alternatives at this level 

may lead to modified or new scenarios, which would then be 

returned to scientists for evaluation using the support tools in 

the first two components. A graphical, public education version of the decision process (the final component) can increase 

public understanding of conservation actions, create a sense 

of involvement and "ownership" in decisions, and alert policy 

makers and resource managers to social judgments of alternative plans. A web-based interface is one option for public and 

policy maker participation. The Internet has the advantages of 

removing geographic restrictions to participation, easy access to 

discussion materials, anonymous input and nonconfrontational 

feedback opportunities (Kingston and others, 2000).

Ecological Issues in Southwestern Florida

The Caloosahatchee and Big Cypress watersheds that make 

up the SWFFS include mangrove- and seagrass-dominated 

coastal estuaries. The benthic-based primary productivity of 

these protected nursery grounds supports fish and microinvertebrate communities that, in turn, feed many commercial 

and recreational marine species. Together with these coastal 

communities, inland short hydroperiod freshwater marshes, wet 

prairies, and wetland forests are habitat for up to 20 Federally 

listed species and 43 species of migratory nongame birds of 

management concern (U.S. Department of the Interior, 2004). 

Southwestern Florida is also one of the most important regions 

that support wide-ranging species such as the Florida panther, 

Florida black bear, and wood stork (Cox and others 1994). 

Because southwestern Florida is one of the most rapidly developing areas across the Nation, concern has arisen among the 

public and decision makers about urban and agricultural growth 

in proximity to extensive public land holdings and privately 

owned natural areas with the ecological attributes just described.

Southwestern Florida Ecological Evaluations

The following discussion provides examples of the types of 

tools and procedures being developed for southwestern Florida 

evaluations. The SWFFS is an ongoing project, and tools may 

change substantially over the course of the study.

Ecological evaluations examine the effects of hydrologic 

change in two geographic regions. In coastal areas, instream 

changes in water-delivery schedules along the Caloosahatchee 

River are evaluated for their effect on the Caloosahatchee River 

estuary. In inland areas, changes in overland hydrologic characteristics are evaluated for their effect on forested and emergent 

wetlands. 

Criteria for assessing ecological effects to southwestern 

Florida are being developed at three principal scales. The criteria address changes in: (1) potential habitat distributions and 

quality for individual species, (2) community composition and 

hydrologic characteristics, and (3) landscape connectivity. 

Species Evaluations

Coastal species evaluation tools include species habitat suitability models for sea trout, American oyster, blue crab, three 

species of sea grasses (Halodule, Thalassia, Syringodium), and 

a submerged freshwater grass (Vallisneria). Inland species evaluation models are now being created or adapted from existing 

models for indicator species of inland wetland health including:

• Long-legged wading birds (for example, blue heron, 

roseate spoonbill, wood stork)

• Short-legged wading birds (for example, white ibis, 

snowy egrets, small herons)

• Wide-ranging mammals (bobcat, the Florida black bear, 

and Florida panther)

• Amphibians (change in proportions of frog species)

• Aquatic fauna (insects, forage fishes, and crayfish)

Figure 3. The Southwest Florida Feasibility Model interface showing 

spotted sea trout habitat suitability.
Figure 3 shows output from a species habitat model for 

spotted sea trout in San Carlo Bay and Pine Island Sound at the 

mouth of the Caloosahatchee River. Maps of potential habitat 

for sea trout are shown for two alternative water-release schedules along the Caloosahatchee River. Habitat quality is grouped 

into five classes, from "best" to "unsuitable," based on five 

modeled components: bathymetry, type of seagrass/substrate, 

flow, salinity, and water temperature. Bar charts shown above 

the maps allow natural-resource managers and policymakers to 

see the contribution of each component to the overall habitat 

score. For example, the bar chart for alternative 2 shows that, 

for the location selected, the suitability of salinity for sea trout 

is low ("A" on the chart), but flow conditions ("E" on the chart) 

are optimal. Suitability scores for the individual components are 

considerably better under the first alternative, as shown on the 

left bar chart.

Community Evaluations

Community evaluations involve the use of hydrologic models 

to evaluate hydrologic characteristics within indicator regions 

in the study area. Indicator regions are representative areas of 

a single community such as hydric pine flatwoods or cypress 

prairie. Predevelopment hydrologic characteristics modeled at 

an indicator region are compared to the same characteristics 

in alternative hydrologic scenarios using a similarity measure. 

Alternatives that more closely preserve predevelopment hydrology of a community are ranked as better for maintaining natural 

conditions at the site. 

Community evaluations also include measures of listedspecies diversity, overall biological diversity, community fragmentation, and the influence of other landscape features such 

as proximity to conservation lands or development. A model 

interface allows managers to spatially assess and map these 

community measures. 

Landscape Evaluations

Landscape connectivity is a measure of how landscape 

elements, such as habitat patches, edges and contiguity, affect 

organism movement and usage of landscape resources 

(Tischendorf and Fahrig, 2000). Land-cover preferences and 

dispersal characteristics of three wide-ranging mammals 

(bobcats, Florida black bear, and Florida panther) are used to 

create least-cost path analyses to weigh the effects of alternative 

hydrologic and land-use scenarios against a predevelopment 

scenario. Least-cost path analysis finds travel paths between 

two locations that have the most suitable characteristics (for 

example, best land cover) for target species. Figure 4 shows 

the least-cost path for the Florida panther moving between the 

Corkscrew Swamp and protected lands north of the Caloosahatchee River along the western coast. Land surrounding the 

Corkscrew Swamp Sanctuary and adjacent to areas of rapid 

development along the coast up to Fort Myers has a high value 

as movement habitat for the panther. 

Decision Models

Ecological models provide essential output for evaluating 

landscape habitat changes, but do not provide it in a form 

that: (1) permits collective evaluations of the habitat 

Figure 4. A least-cost path for Florida Panther movement (shown in 

green) between Corkscrew Swamp and Myakka River State Park.

Figure 5. The decision support process.

changes, or (2) allows decisions to be made from multiple 

evaluations. Decision analysis provides tools for systematically 

formulating and evaluating multiple criteria and explaining why 

(under several conflicting preferences) a particular decision was 

made (Lahdelma and others, 2000).

 Figure 5 presents a procedural relation between scientific/

technical evaluations and policy making in an adaptive management framework. Conceptual models are an effective initial tool 
for group identification of sources of stressors and linkages 

to attributes in the environment. Criteria, or performance 

measures, are selected as measurable values of identified 

attributes and are used to evaluate success of implemented 

plans. For example, if an attribute of the natural environment is 

oyster community structure and function, then criteria for that 

attribute may be oyster growth, disease, mortality, and recruitment. Scientists place expected values on these criteria under 

alternative scenarios of environmental change. This task is 

usually accomplished with ecological modeling. Decision 

makers then determine the importance of each of these criteria and use this information to evaluate different alternatives. 

Decision models aid in weighing and evaluating alternatives 

and may also help decision makers pinpoint conflicts between 

objectives and conceptualize new alternatives that minimize 

these conflicts (Ozernoy, 1984). Once an alternative is selected 

and implemented, expected environmental change is compared 

to actual conditions through monitoring and directed experimentation, which may lead again to reevaluations of criteria and 

implemented plans. 

Multicriteria decision analysis calls for agencies to define 

issues, propose alternative solutions, and develop measurable 

criteria for evaluating the performance of each alternative. 

Decision tools and graphical methods help provide a critical 

and careful examination of the process. In southern and southwestern Florida, the need for evaluation approaches that help 

to structure the decision process is increasingly felt by natural 

resource personnel as indicated by results from a preliminary 

decision support survey (Pearlstine and others, 2003).

References

Cox, J., Kautz, R., MacLaughlin, M., and Gilbert, T., 1994, 

Closing the gaps in Florida’s wildlife habitat conservation 

system: Tallahassee, Florida, Office of Environmental 

Services, Florida Fish and Wildlife Conservation 

Commission.

Kingston, R., Carver, S., Evans, A., and Turton, I, 2000, Webbased public participation geographical information systems: 

An aid to local environmental decision-making: Computers, 

Environment and Urban Systems v. 24, p. 109-125.

Lahdelma, R., Salminen, P., and Hokkanen, J., 2000, Using 

multicriteria methods in environmental planning and management: Environmental Management, v. 26, p. 595-605.

Ozernoy, V., 1984, Generating alternatives in multiple criteria 

decision making problems: A survey; in Y. Haimes, and V. 

Chankong (eds.), Decision Making with Multiple Objectives: 

New York, Springer-Verlag.

Pearlstine, L.G., and Mazzotti, F.J., 2003, A spatially-explicit 

decision support system for Everglades risk assessment and 

restoration: An annual report to the U.S. Geological Survey 

Florida Integrated Science Center: Fort Lauderdale, Florida, 

Fort Lauderdale Research and Education Center, University 

of Florida.

Rauscher, H.M. 1999, Ecosystem management decision support 

for Federal forests in the United States: A review: Forest 

Ecology and Management, v. 114, p. 173-197.

Tischendorf, L., and Fahrig, L., 2000, On the usage and measurement of landscape connectivity: Oikos, v. 90, p 7-19.

U.S. Department of the Interior, 2004, Science plan in support 

of ecosystem restoration, preservation, and protection in 

South Florida: Accessed on August 26, 2004 at http://sofia.

usgs.gov/publications/reports/doi-science-plan/

For more information contact:

Donald L. DeAngelis, Project Officer

U.S. Geological Survey 

Florida Integrated Science Center

Water and Restoration Studies

University of Miami

P.O. Box 249118

Coral Gables, Florida 33124

ddeangelis@umiami.ir.miami.edu

(305) 284-3974

Leonard Pearlstine and Frank J. Mazzotti 

Principal Investigators

University of Florida 

Ft. Lauderdale Research and Education Center

3205 College Ave

Ft. Lauderdale, Florida 33314

pearlstn@ufl.edu fjma@ufl.edu

(954) 577-6300

Tomma Barnes, Michael Duever, and Janet Starnes

Project Leaders

South Florida Water Management District 

Lower West Coast Regional Service Center

2301 McGregor Boulevard

Fort Myers, Florida 33901

tbarnes@sfwmd.gov 

mduever@sfwmd.gov jstarne@sfwmd.gov

(239) 338-2929