Bosque Evapotranspiration Studies at the University of New Mexico: Infrastructure for Exploring the Ecohydrology and Biometeorology of the Middle Rio Grande

Cliff Dahm, James Cleverly, Jim Thibault,

Julie Allred Coonrod, Dianne McDonnell,

and Mary Harner

University of New Mexico

Departments of Biology and Civil Engineering

UNM

Hydrogeoecology

1930

2002

Middle Rio Grande

Channel & Riparian Zone

Rio Grande, New Mexico

Middle Rio

Grande

ABQ

Photo: A. Molles

Photo: D. Gilroy

3-D Eddy Covariance

Sensor

•Direct measurement of ET

•Self-test for accuracy

•Consistent with the application of

atmospheric physics

Populus deltoides ssp. wislizenii (Rio Grande Cottonwood)

Native Exotic

Tamarix chinensis (Saltcedar)

Elæagnus angustifolia (Russian Olive)

Flooding

Cottonwood

Nonflooding

Cottonwood

Nonflooding Saltcedar

Flooding Saltcedar

Flooding Russian-olive

Towered Sites

Short Interflood Interval < 2yrs (flood site)

Long interflood interval > 10yrs (nonflood site)

Saltcedar flooding site

Bosque del Apache NWR

Flux tower

Photo: Bosque del Apache

Sevilleta ET, 2001

0

1

2

3

4

5

6

7

90 120 150 180 210 241 272 302

Day of Year

Evapotr

anspiration

(mm

)

ET varies throughout the growing season with tree response. In

addition, ET varies daily with temperature, humidity, and wind. The

ET measurements are made with equipment that requires regular

maintenance to obtain as near-continuous data as possible. To estimate

ET for days with equipment malfunctions, a curve is fit to the data.

ET trend lines - All sites 2001

0

1

2

3

4

5

6

7

8

9

90 120 150 180 210 240 270 300 330

day of year

ET

(m

m/d

ay) Albuq

Belen

Sevilleta

Bosque del

Apache

Apr May Jun Jul Au Sep NovOct

ET varies from site to site with the dense salt cedar forest

at Bosque del Apache typically having the greatest ET –

range from 70-122 cm yr-1

Annual ET

2

2.5

3

3.5

4

4.5

2000 2001 2002 2003

Year

ET

Cottonwood/Saltcedar/Russian Olive

Saltcedar/Saltgrass (~150 gal/plant-yr)

Russian Olive/Willow

• Site location

• Drought

• Vapor Pressure Deficit

• Groundwater

Cottonwood/Willow/(Alfalfa)

Dense Saltcedar (~200 gal/plant-yr)

Cottonwood

site

Salt Cedar

sites

Satellite Scaling

Landsat 7 ETM+ Remote

sensing (NASA)

Calibrated with:

Leaf area index

Day length

Daily min/max temperature

Groundwater salinity

Groundwater nitrate

Water budget

(106 m3 yr-1) San Juan-Chama

Inflow

Tributary Inflow (gauged)

Municipal Waste Water

Albuquerque Storm Drain

Inflow

Open Water Evaporation

Irrigated Agriculture & Valley-Floor Turf

68

Otowi Gauge 1419

(370-2714)

74

(37-111)

123

(86-160)

117

86

6

Shallow Aquifer

271

364

Discharge from Aquifer to Surface

Recharge to Aquifer

Riparian Evapotranspiration (ET) ~ 150-250

167

(93-241)

123

(99-222)

173

(49-281)

Riparian ET, Irrigated Agriculture,

& Open Water Evaporation

Elephant Butte Reservoir

Evaporation

To Downstream Users (370-1770)

San Acacia Gauge

Middle R

io G

rand

e

Freshwater Biology Dahm et al. 2002

47:831-843

60

80

100

120

140

ET

(c

m/y

r)

2003 2004 2005

Year

Bosque del Apache: monospecific saltcedar thicket

San Acacia: saltcedar/saltgrass

La Joya: Russian olive/coyote willow

Albuquerque's South Valley: cottonwood

Restoration water salvage

Understory Russian olive and saltcedar

removed from South Valley Albuquerque

cottonwood forest between 2003 and 2004

growing seasons

First year reduction in ET of 9% while

other sites increasing by 12% (total = -

21% or -26 cm/yr)

Second year increase matched increase at

other sites: 0 cm/yr Non-native understory cleared

Groundwater recession

5

10

15

20

25

30

PPT

(m

m/day

)

0

2

4

6

8

10

12

ET

50 100 150 200 250 300 350

Day of Year

BDAS 2003 ET (mm/day)

-50

0

50

100

150

200

250

300

350

GW

Depth to Groundwater (cm)

4

5

6

7

8

9

ET

(9

-da

y a

vera

ge

, m

m/d

ay)

-7.5 -5 -2.5 0 2.5 5

dWT/dt (9-day average, cm/day)

Rising Falling

1

3 2

1 Draining begins, soil too

saturated for taproot

elongation, uptake continues

at original capillary fringe

3 Uptake continues at

deeper water table, uptake

at original water table

curtailed by soil drying

2 Taproot growth exploits

deeper water table, uptake

continues at or near original

capillary fringe

E-T-R Arrays: An Integrated Observing System for Partitioning

Evaporation-Transpiration-Recharge

Hydrologic Response Units

Conceptual Hydrologic

Landscape

ETR ARRAY CONCEPT

•Discrete sampling of soil moisture,

head, etc. in a Finite Volume…

•Precise Footprint

•Explicit Partitioning of E-T-R…

•Finite Volume Model Formulation

•Optimal Sensor Network Design….

•In-Situ Parameter Estimation…

•In-Situ Evaporation-Transpiration-

Recharge

•Remote sensing reference point…. Experimental Design Collaborators: Cliff Dahm,

Chris Duffy, Peter Beeson, Fred Phillips,…..

New Mexico EPSCoR: Regional Hydrology

Cliff Dahm, Robert Bowman, Zhorab Samani, James Cleverly, Marcy Litvak, Salim

Bawazir, Julie Coonrod, Jan Hendrickx, Karl Benedict, Rick Watson, Mike Inglis,

Greg Cook, Louis Scuderi, Stan Morain, Enrique Vivoni, and Barbara Kimbell

EPSCoR: Experimental Program to Stimulate

Competitive Research - Hydrology Goal: Leadership in instrumentation and algorithm development for

regional hydrologic modeling and ET estimation in semiarid environments

Ground-based

measurements: Fluxnet+

NM

Remote sensing: scaling,

ET estimation, and

algorithm

intercomparison

Geospatial integrated

modeling: distributed

hydrological processes,

computation, and data

products

Ground-Based

Measurements

(input and

validation for

Models)

Satellite Imagery

(input for maps of

ET, vegetation change)

Geospatial Integrated Modeling &

Geographic Information System

Databases and Products

NM EPSCoR

Hydrology

Flux tower network

NM EPSCoR Core Network

Rio Grande/Chama/Rio Salado riparian corridor (cottonwood, salt cedar, Russian olive, moist soil/sediment)

Lower Rio Grande agriculture and open water

Sevilleta NWR (upland grassland, desert, and piñon-juniper)

Extended Network

Valles Caldera and high elevation grasslands and conifer forests—SAHRA and LANL

Jornada experimental range lowland desert—USDA-ARS and LTERnet

Bosque Evapotranspiration

Areal extent of the bosque has expanded substantially in recent decades

Bosque ET responds to leaf area indices, the annual hydrograph, and dominant plant species

Annual ET depletions from the bosque are not constant

Bosque restoration for water salvage must aggressively target resprouting vegetation

Cottonwood and salt cedar have fundamentally different strategies for dealing with water stress from a declining water table

Development of ETR arrays and an ET network are next steps in a better regional water budget

The frog does not drink up the pond in which he lives.

Native American Proverb

If our access to our water is taken away, our hope for the

future is taken too.

Former Chairman Peterson Zah (Navaho Nation)

Acknowledgements Funding Agencies:

ESA Collaborative Program Bosque Improvement Group (ET project)

NSF Award DEB-9903973 (CRB project) NM Interstate Stream Commission

NSF Award DEB-9972810 (IGERT project) NASA Award NA65-6999

NSF EPSCoR Project Award

Cooperating agencies and institutions include:

Bosque del Apache National Wildlife Refuge

Middle Rio Grande Conservancy District

Sevilleta National Wildlife Refuge

City of Albuquerque Open Spaces Division

Rio Grande Nature Center

New Mexico State University

U.S. Bureau of Reclamation

New Mexico Inter-agency ET Workgroup

New Mexico Inter-agency Bosque Hydrology Group

New Mexico Tech

US Forest Service