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