land-based resource characterization & threats in the mbrs land-based resource characterization...
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Land-Based Resource Land-Based Resource Characterization & Threats in the Characterization & Threats in the
MBRSMBRS
Melissa Bailey & Paul Campbell
Tufts University
WatershedsWatersheds
“an area of land within which all waters flow to a single river system”
---Heathcote 1998
“the specific land area that drains water into a river system or other body of water”
---The World Bank
Features of a Typical Watershed
Reef
Overlandflow
Groundwaterflow
Sewage Runoff
Soil Erosion
FertilizersExcess Nutrients
Pesticide Residues
Chemical Infiltration
Potential Stresses in Watershed
What is the integrated watershed What is the integrated watershed management approach?management approach?
Integrated Watershed Management
Principles & Practice
Watershed water
resources
Water Users
Socioeconomics
Watershed Ecosystem
Water supply
Water demand
Action Point
Action Point
Demand-oriented measures
Supply-oriented measures
Modified from Heathcote, Isobel. (1998). Integrated Watershed Management: Principles and Practice. p. 4.
Why “Transboundary”?Why “Transboundary”?
• Watersheds do not “fit” into political boundaries or jurisdictions
• Incompatible management of a resource that cannot be molded to our local, regional or national constructs
Why “Transboundary”? Why “Transboundary”?
Watershed DelineationsWatershed Delineations
Quintana Roo (Mexico)
Rio Hondo (Mexico-Belize)
% Land Cover% Land Cover
Land Cover Type Quintana Roo Rio Hondo Rio Motagua Chamelecon Ulua
Agriculture 2.60% 11.30% 32.90% 74.60% 76.10%
Broadleaf forest 70.50% 60.90% 41.10% 4.50% 3.60%
Coastal vegetation - - 0.03% 0.01% 0.10%
Mangrove 5.60% 0.47% 1.90% 0.03% -
Mixed forest - - 6.50% 2.50% 5.90%
Needleleaf forest - - 3.10% 10.30% 13.00%
Scrub/shrub 14.80% 24.30% 9.80% 0.05% 0.08%
Urban 0.27% 0.24% 0.40% 2.10% 0.14%
Water body 0.91% 0.18% 1.20% 0.60% 0.80%
Wetlands 4.80% 1.40% 2.30% 5.10% 0.26%
Savanna 0.10% 1.20% 0.60% - -
Sparse or no vegetation 0.33% - 0.11% - 0.02%
Other 0.09% 0.06% 0.21% -
Quintana RooQuintana Roo
% Land Cover: Quintana Roo
Broadleaf forest, 70.50%
Mangrove, 5.60%
Scrub/shrub, 14.80%
Wetlands, 4.80%
Agriculture
Broadleaf forest
Mangrove
Scrub/shrub
Urban
Water body
Wetlands
Savanna
Sparse or no vegetation
Other
Rio HondoRio Hondo
% Land Cover: Rio Hondo
Broadleaf forest60.90%
Agriculture11.30%
Scrub/shrub24.30%
Agriculture
Broadleaf forest
Mangrove
Scrub/shrub
Urban
Water body
Wetlands
Savanna
Themes in Land CoverThemes in Land Cover
• Forest Covers: – Reduce runoff &
stabilize soils– Improve infiltration and
filtration of water– Ecological
significance: habitat for interior species
Themes in Land CoverThemes in Land Cover
• Agriculture:– Can be
environmentally sound or unsound
– Ecological significance: variable--crop/farm practice
Themes in Land CoverThemes in Land Cover
• Wetlands & Mangroves:– Buffering of water
contaminants and sediments
– Reduce flooding– Ecological
significance: nursery & breeding grounds
Themes in Land CoverThemes in Land Cover
• Urban Development:– Can concentrate & act
as a sink for pollutants– Can increase flood
potential – Increase
erosion/sedimentation– Increase
fragmentation of habitat
Rio HondoRio Hondo
• Mexico portion:– Coastal Aquaculture – Major crops: corn &
sugar cane– Cattle Ranching
• Belize portion:– Sugar cane – Livestock
Quintana Roo, Yucatan PeninsulaQuintana Roo, Yucatan Peninsula
• Most communities surveyed did not have major agricultural production
– Cattle Ranching
– Small amount of crop farming
– Aquaculture
Agricultural Activities & Risk Potential– Overall, qualitative data show that chemical
fertilizers (NPK and urea) and pesticides (in particular, Paraquat and 2,4-D) are common. The actually appropriateness and amount of fertilizer and pesticide applied would require a more rigorous survey of agriculture in region.
– Need to have more concrete information about what crops and farming practices that are common within each watershed.
Vulnerability Analysis: Sedimentation
RUNOFF model
Rainfall
Slope
Soil Porosity
Land Cover Modified RUSLE
Input Institutional & Socioeconomic Factors
With Relative Erosion Potential for a map of Areas of High Environmental Stress
Missing Elements for Sediment Missing Elements for Sediment Model in the MBRSModel in the MBRS
• Updated land cover
• More specific agriculture information (e.g. type of crops, farm practice)
Next Step Model for the MBRSNext Step Model for the MBRS
• Composite of potential stressors in each watershed = “maps” areas under most stress and in need of intervention
What we need to complete this composite…• Opinion on how much each stressor should
factor or “count” in the analysis• Better data on water quality, streamflow,
infrastructure, sanitation