Executive Summary (PDF 341 kb)

Full text: Watershed Analysis for the Mesoamerican Reefs (6545 kb)

Acknowledgments 

Project Summary 

Project Background 

Key Findings 

Overview of Methodology 
Watershed Delineation 
Hydrologic Modeling 
GIS Data Sets 
Modeling Erosion and Sediment Delivery 
Precipitation and Rainfall Erosivity 
Vulnerability of Land to Erosion 
Modeling Runoff and Pollutant Delivery 
Circulation Modeling 
Model Calibration and Validation 
Limitations of the Analysis 
Limitations of Hydrologic Modeling 
Limitations of Circulation Modeling 

Analysis Results 
1. Sediment and Pollutant Delivery given Current Land Cover (2003/04) 
2. Comparison of Results for Current Land Cover (2003/04) to Hypothetical Natural Land Cover 
3. Comparison of Current Land Cover to Three Development Scenarios in 2025 
4. Extreme Events 
5. Buoyant Matter Transport along the MAR 
6. Vulnerability of the Land to Erosion 
7. Local Sources of Sediment and Nutrients 

Conclusion 

Additional Technical Notes 

List of Figures

Figure A. Annual Sediment Delivery from MAR Watersheds 
Figure 1. Watersheds of the Mesoamerican Reef Region 
Figure 2. Soil Erosivity (K-factor) 
Figure 3. Annual Precipitation Distribution 
Figure 4. Rainfall Erosivity (R-factor) 
Figure 5. Temporal Relationship Between N-SPECT River Discharge Estimates and the Mean Colored Detrital Matter (CDM) Absorption Coefficient from Imagery for the North of Honduras 
Figure 6. Sediment and Nitrogen Delivery by Basin (for current land cover) 
Figure 7. Modeled Sediment Delivery from “Current” and Hypothetical “Natural” Land Cover 
Figure 8. Land Cover Distribution within each Scenario 
Figure 9. CDM Plume Extent on November 14, 2000 
Figure 10 Estimated Monthly River Discharge from N-SPECT  
Figure 11. Simulated Buoyant Matter Concentration Along the MAR for December (Current Land Cover and Sustainability First Scenarios) 
Figure 12. Maximum Annual Simulated Buoyant Matter Concentration Along the MAR (Current Land Cover and Sustainability First Scenarios) 
Figure 13. Mesoamerican Reef Mapped by Buoyant Matter Concentration (Current Land Cover and Sustainability First Scenarios) 
Figure 14.  Vulnerability of Land to Erosion 
Figure 15. Average Contribution of Sediment, Nitrogen, and Phosphorous by Sub-basin 

List of Tables

Table 1. N-SPECT C-factor Coefficients 
Table 2. N-SPECT Runoff Curve Numbers (Coefficients) by Land Cover Type and Soil Hydrologic Group 
Table 3. Pollutant Coefficients for Phosphorous, Nitrogen, and Total Suspended Solids (TSS) 
Table 4. Comparison of Natural and Current Land Cover (percent in each cover type) 
Table 5. Comparison of Regional Results for Annual Model Runs for Current and Natural Land Cover 
Table 6. Comparison of Land Cover Scenarios (percent in each cover type) 
Table 7. Comparison of Regional Results for Annual Model Runs for Current Land Cover and Three Scenarios in 2025 
Table 8. Percentage of Erosion, Nitrogen, and Phosphorous Sources by Country within MAR Drainage