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Everglades Restoration > River of Grass Evaluation Methodology
River of Grass Evaluation Methodology (ROGEM)
What is ROGEM?
The River of Grass Evaluation Methodology (ROGEM) is a tool that was developed and used by the Central and Southern Florida Project Comprehensive Review Study (Restudy) subteams to quantitatively describe potential habitat quality responses to alternative plans developed for the Restudy. A subset of the Restudy team - the Alternatives Evaluation Team - evaluated and assisted the development of alternative plans during the alternatives development and evaluation process of the study. The Alternatives Evaluation Team broke up into subteams based on geographic subregions. A major responsibility of each subteam was to evaluate in detail the alternative plans and report back the findings to the Alternatives Evaluation Team. The subteams used professional expertise to develop mathematical equations whose output would indicate relative habitat quality in the natural system that would result from the plans evaluated.
The River of Grass Evaluation Methodology (ROGEM) was originally developed during the Reconnaissance phase of the Restudy. This classification system followed that described by Davis et al. in Davis and Ogden, 1994. During the Reconnaissance phase, equations were developed for Lake Okeechobee; St. Lucie Estuary; Caloosahatchee Estuary; Sawgrass Plains; Wet Prairie/Slough, Tree Island, Sawgrass Mosaic; Southern Marl Prairie; Sawgrass Dominated Mosaic; Cypress Swamp; and Florida Bay. For this Feasibility phase of the study, the classification was revised to be consistent with conceptual landscape spatial scale models under development by the Natural Systems Team of the Southern Everglades Restoration Alliance and other ad hoc Restudy subteams. The revised subregions are listed below.
Peer review of the methodology and equations was directed by the Science Sub-group of the South Florida Ecosystem Restoration Task Force. The peer review was completed in February 1997. The methodology and subregion equations were revised in response to the reviewers’ and Restudy team members’ comments and suggestions, to incorporate information from the conceptual models drafted by the Natural Systems Team, and to utilize more detailed hydrologic information that was available during the present study.
ROGEM equations and numerical outputs were developed for the following subregions within the Central and Southern Florida Project area: Lake Okeechobee, St. Lucie Estuary, Caloosahatchee Estuary, Florida Bay, Biscayne Bay, freshwater wetlands within the Loxahatchee National Wildlife Refuge, Water Conservation Areas 2 and 3, Everglades National Park, and Model Lands. These equations and numerical outputs are based on linkages between hydrologic characteristics and habitat restoration targets identified by the subteams. Output from the equations range from zero, which indicates low habitat quality and failure to achieve hydrologic restoration targets, to one, which indicates that the plan evaluated fully meets the restoration objective and would provide optimum habitat quality.
Linkage with Other Models
Most of the variables within the equations are hydrologic due to the importance and relationship of hydrology to habitat quality, and because the study area’s hydrology will be modified by alternatives developed as part of the Restudy. Hydrologic information was provided by the spatially explicit South Florida Water Management Model (SFWMM).
ROGEM Outputs
Outputs were calculated for different hydrologic alternatives for each subregion and range in value from zero to one. The equations provided output for the existing (1995 Base) and future without project (2050 Base) conditions, and for alternatives A through D13R. Outputs are compared with target restoration conditions assumed to approximate optimum habitat that would score 1.
How ROGEM was used in the Restudy
Equations were developed for each of the subregions based on linkages between hydrologic conditions and habitat quality in natural areas. Use of the equations resulted in numerical outputs (scores) being generated for each of the subregions. According to the methodology, the base or alternative plan with the highest numerical score is, relatively speaking, the best plan for that natural area. Use of the methodology provided information about how close to or far away from restoration goals an alternative is. Evaluating why an alternative didn’t result in a high score also helped identify what needed to be changed in subsequent alternatives. The methodology helped each subteam organize their knowledge about the ecosystem, communicate suggestions and requests to the alternative plan developers on how to improve subsequent alternative plans, and clearly communicate the restoration goals for particular areas and/or resources within the areas. The ROGEM scores were also used in the benefits and incremental analyses conducted during the study and described in Section 7 of the Feasibility Report.
 Numeric scores. Click on the image to the left to view an example of the matrices created by the subteams.
Habitat quality matrices were developed which presented the numeric scores by subregion for alternatives A through D13R and the base conditions. The variables in each subregion’s equation are computed using hydrologic data from the South Florida Water Management Model (accessed on this website at "Evaluation of Alternative Plans"). Therefore, the overall ROGEM scores for each subregion are actually obtained from combining multiple scores from the hydrologic variables.
Supporting documentation explaining the variables and equations was developed by each subteam and is presented in Appendix D of the Feasibility Report. The documentation includes an interpretation of the numerical scores relative to the long-term ecological objectives for the appropriate natural area. The documentation provides additional explanations of how the subteam interpreted the scores relative to the targets. The subteams recommend that numeric scores only be compared within each subarea as a basis for comparing how well several different plans performed at moving towards or achieving the subareas’ target(s). Because the subteams felt so strongly about this, the final comparisons of the plans were made using three summary evaluation criteria: plan ranking, plan grade, and plan color. Although these three evaluation criteria were derived from the numerical output from the River of Grass Evaluation Methodology it was believed by the subteams that presenting the results for the plans in a qualitative rather than quantitative way avoids implying that the results are more precise than they actually are. Here is how the three criteria were developed:
Plan Ranking
For each subregion, the alternative plans A, B, C, D, and 2050 Base were ranked from one through five. The best plan (highest ROGEM score) for each sub-region was awarded a score of one (1), the worst plan earned a score of five (5), and the intermediate plans received values from two (2) through four (4). Ties were dealt with by averaging. The results of this evaluation are included in Section 7 and Appendix D of the Feasibilty Report. The plan with the lowest cumulative score received the highest rank. For example, Plan D, the highest ranked plan, scored 45 points compared to the 2050 Base condition that received 102 points.
Plan Grades
Plan grades were assigned based on the numerical output from the River of Grass Evaluation Methodology equation for each natural area. A letter grade (A, B, C, D, or F) was assigned based on these numeric scores and the following interpretation: a letter grade A indicated the plan was excellent at meeting the performance measure targets and restoration objective(s); letter grade F failed to meet the performance measures, intermediate letter grades indicated partial fullfillment of the targets and objectives, similar to the letter grading system used in academia. The letter grades indicate how well each alternative plan (including Plan D13R) and the 2050 Base performed. More than one plan could receive a similar grade for a natural area if two or more of the plans performed similarly for the area. For example, Loxahatchee National Wildlife Refuge earned a letter grade A for plans A through D since it fully met the restoration target and the restoration objective. The Feasibility Report and Appendix D list the plan grades for the subteams.
Plan Colors
Plan colors (green, yellow, and red) were assigned by converting plan grades (which are based on ROGEM numeric scores) into a "best professional opinion" prediction by each subteam on the likelihood of each plan and base case achieving the long-term ecological objectives identified for the performance measures. Green indicates the current plan is likely to recover and sustain the ecological objective described by the performance measures, and that further plan improvement is unnecessary or a low priority. Yellow indicates achievement of the long-term objectives is uncertain, and that improvement in the plan is needed. Red indicates the recovery and long-term sustainability of the target objective are unlikely, and that the current plan requires improvement if these targets are to be met. The Feasibility Report and Appendix D of the report lists the colors for all the alternatives.
Where to Get More Information About ROGEM
The ROGEM analysis and results are discussed in more detail in Section 7 and Appendix D of the Integrated Feasibility Report and PEIS.
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