USGS Climate Change-Related Work 

on the U.S. / Mexico Border

Diana Papoulias

USGS, Columbia Environmental Research Center
BORDERLANDS

Setting the Scene – Southwest is expected to get hotter and 

experience more intense precipitation events with increased variability.
Challenge Areas

• Water Quality and Availability

• Natural Hazards

• Ecological Resources

• Energy and Mineral Resources

• Human Health

• Human Impacts

• Environmental Security, Border Management, and 

Protection
Highlights

– The US-Mexico Border GIS (BEHI)

– DOI Southwest Climate Science Center

– Santa Cruz Watershed Ecosystem Portfolio Model

– Contaminants in the Santa Cruz River

– Modeling Flooding at Ambos Nogales

– Flood Warning and Modeling in Nogales Sonora

– TAAP – Mesilla Basin Studies

– American Drylands – modeling dust events
BEHI -PROVIDING THE TRANSBORDER 

FRAMEWORK

• Borderlands Environmental Health Initiative
BEHI Partners

• Instituto Nacional de Estadística, Geografía e Informática (INEGI)

• Secretaria de Medio Ambiente y Recursos Naturales (SEMARNAT)

• Instituto de Salud Publica (INSP)

• DOI US-Mexico Border Field Coordinating Committee (FCC)

• Southwest Consortium for Environmental Research and Policy (SCERP)

• Comisión Nacional de Agua (CONAGUA)

• Comisión Internacional de Limites y Aguas (CILA)

• International Boundary and Water Commission (IBWC)

• UT Center for Research in Water Resources (CRWR) Rio Grande

• Environmental Protection Agency Border 2012

 BEHI HOMEPAGE http://borderhealth.cr.usgs.gov/projectindex.html
DOI CLIMATE SCIENCE CENTERS
DOI LCCs

LCC Homepage: www.fws.fov/science/shc/lcc.html
The River 

Runs North

Except When 

It Runs South

SANTA CRUZ WATERSHED MODELING
2010

Economic 

// Market 

Social // Human Land Price

Well-Being

Biophysical // 

Ecological 

Value

Describing the binational watershed, in terms of Ecosystem 

Services provided to humans, based on Sustainability’s 3-

legged stool approach, in an online decision support tool.

Ecosystem services are “The benefits and goods that people receive from 

the environment.”--Millennium Ecosystem Assessment, 2005

Santa Cruz Watershed Ecosystem Portfolio 

Model (SCWEPM)
0 0.5 1 1.5 2 2.5 3

Prescription hormones

PAH

Biogenic hormone

Pesticides

Nonionic detergent metabolites

Disinfectants

Wastewater compounds

Non-prescription drugs

Fire retardants

Prescription drugs

Fragrances

Plasticizers

Sterols

Maximum Concentration for the Group

Contaminants in the Santa Cruz River

Link to climate change research: climate 

change can worsen contamination problems 

by decreasing the amount of water in rivers 

and aquifers. This study provides baseline 

information and continued monitoring of 

the effluent dominated Santa Cruz River and 

groundwater at Tumacacori National 

Historical Park. Climate change will affect 

concentration, degradation, and movement 

of emerging contaminants which have the 

capacity to kill plants and animals, impair 

riparian ecosystem function and affect 

humans with well water that is derived from 

infiltrated river water.

micrograms per liter (ppb)
Groundwater and contaminant transport 

modeling

Link to climate change: when 

coupled with downscaledclimate- and watershed 

models, these can be used to 

predict changes in water 

availability and movement of 

contaminants between 

groundwater and surface 

water in response to 

different climate scenarios.

Concentration Values

NO3_mg/L

0.21 - 10.00

13.00 - 20.00

30.00

31.00 - 40.00

Concentration Value

As_ug/L

1 - 10

11 - 20

24 - 30

33 - 40

43 - 50

54 - 60
Modeling alternative scenarios

Flooding at Ambos

Nogales
Modeling floods in Ambos Nogales 

Multiple partnerships
Rain Gages

Precip On Milimeters

(mm)

Inches 

(in.)

7/31/2010 1.524 0.06

7/30/2010 52.07 2.05

7/29/2010 17.78 0.7

7/28/2010 7.62 0.3

7/27/2010 13.208 0.52

7/22/2010 7.112 0.28

7/20/2010 1.27 0.05

7/19/2010 24.384 0.96

• No Radar available (Nogales in shadow for NWS)

• One Rain precipitation gages now being installed

• All data is available in real-time in maps on-line! 
Satellite Data Collection System Data

Receiving Station

More to come...
TAAP – TRANSBOUNDARY AQUIFER 

ASSESSMENT PROJECT

17

• Mesilla Basin has interconnected 

streamflow (the Rio Grande) and 

groundwater (the Mesilla Basin, 

or acuifero Conejos-Medanos in 

Mexico).

• Major water use: agriculture in New 

Mexico, and across border in Mexico. 

• Important municipal uses: new 

wellfields for El Paso and Ciudad 

Juarez.

• Cross-boundary river flow governed by 

interstate and international treaties.

CABALLO DAM

AGRICULTURAL 

IRRIGATION

AGRICULTURAL 

IRRIGATION
Model Development: USGS MODFLOW-2005 Code “Farm Process”

REGIONAL 

MODEL AREA –

LOWER RIO 

EXAMPLE SUB GRANDE -MODEL – “RINCON” 

AGRICULTURAL SERVICE AREA

• Upgraded model accounts 

for and integrates: 

surface diversions, return 

flow, crop type, & 

supplemental well 

pumpage

• Can be tied to “real-time” 

water supply conditions 

and to remote sensing 

crop data for rapid 

changes or updates

• Allows for supply and 

demand analysis, 

pumping predictions, 

effects of administrative 

rules for droughts or water 

rights
Model Development: Expanding Model Domain into Mexico

• Contract executed with CONAGUA & SGM (Mexican 

Geological Service) for a basic geohydrologic data 

study in Conejos-Medanos

• New Mexico WRRI has updated the geologic 

framework with cross-sections and structure maps of 

aquifer units, and a binational database has been 

created

• USGS is making hydraulic parameter estimates from 

textural analysis of well log data

• USGS has sampled select wells in Mesilla Bolson for 

hydrochemical analysis including age dating.

• Results will be integrated into FARM PROCESS model 

and enhance management of this critical resource 

under changing conditions

WELLS IN MODEL DOMAIN

NEW WELLFIELD AND PIPELINE

UPDATED GEOLOGIC FRAMEWORK 
SALTON SEA ECOSYSTEM

Salton 

Sea

Pacific Ocean

Gulf of California

Arizona

California

Colorado 

River

Yuma

Los Angeles

San Diego

Tijuana

USA

Mexico

La Quinta
Pending water transfers to urban southern California 

will shrink the size of the lake and accelerate the 

salinity increase

With no action:

By 2018

-elev to -235

-salinity to 60,000 mg/l

By 2078:

-elev to -260 ft;

-salinity to 300,000 mg/l
Salton Sea Area Wind Vectors - 2002

15 MPH is critical 

threshold for dust 

generation. These 

regularly occur over 

the most vulnerable 

sites
American Drylands

• Borderlands central area is the source of dust 

that is frequently transported during high 

wind events.

Modis image of a dust

storm on April 29, 2010
High-resolution climate modeling for dust 

events