Climate C Change a and t the R Rio G Grande David S S. Gu - - PowerPoint PPT Presentation

▶

Mar 12, 2024 226 likes •350 views

1/9 Climate C Change a and t the R Rio G Grande David S S. Gu Gutzler wi with th Ne Nels Bj Bjarke, e, Sh Shale leene Chavarria a and Nolan T Townsend University o of Ne New M Mexico Elephant Butte Reservoir gutzler@unm.edu

SLIDE 1

Climate C Change a and t the R Rio G Grande

David S

S. Gu

Gutzler

wi with th Ne Nels Bj Bjarke, e, Sh Shale leene Chavarria a and Nolan T Townsend

University o

f Ne

New M Mexico

gutzler@unm.edu

Elephant Butte Reservoir Jan 8, 2019

§ Observed and projected climate change § The problematic future of snowmelt runoff § Lower flows / Increased stress on water resources

1/9

SLIDE 2

Observed T Temperature a and Pr Precipitation i in N NM

updated from NM Water Supply Vulnerability Working Group (2015)

large,

ngoing trend

no long-term trend (yet) lots of variability 1930 1970 2010

2/9

SLIDE 3

Streamflow a and S Snowpack i in t the R Rio G Grande H Headwaters

Rio Grande headwaters southern Colorado Del Norte Snow Course Sites Chavarria & Gutzler (2018)

~25% decrease 1958-2015

1958 1980 2000 2015

SWE (1 April) Q (Annual)

minimal trend (but earlier peak runoff)

3/9

SLIDE 4

Climate Pr Projections: D Declining Snow a and R Runoff

Brown & Mote (2009)

End-of-Century Snowpack Change

4/9

Milly et al. (2005)

Mid-Century Streamflow Change

current climate

- - 2020-2050
- - 2070-2100

3 different model projections (A1B-forced)

Hurd and Coonrod (2012)

Projected Rio Grande Hydrographs

SLIDE 5

Chavarria & Gutzler (2018) Bjarke & Gutzler (2019)

Increasing i importance o

Spring p precipitation f for R RG f flows

1 Apr SWE Based o

1 A Apr SW SWE

1987-2015 1958-1986 Apr-Jul Discharge [Mm3] 1 Apr SWE

In r recent d decades: Reduced r runoff p prediction s skill f from SW SWE

1951-80 1971-2000 1986-2015

5/9

SLIDE 6

Newer Pr Projections ( (CMIP5 P5, U US BoR BoR): ): Inflow i into EB EB Reservoir a at S San Mar Marcial al

1970 2020 2070

Observed and projected inflows into Elephant Butte Reservoir

climate model simulation

bserved annual flows

see Nolan’s poster

model output (natural flow)

models (1964-2013) models (2021-2070) Distribution of annual flows at San Marcial

Townsend & Gutzler (2019)

6/9

SLIDE 7

Model Pr Projections o

Snowpack a and S Snowmelt R Runoff in t the H Headwaters

Bjarke & Gutzler (2019)

CMIP5/BoR models that reproduce historical changes in SWE and Q project lower flows in future decades ... more consistent with previous projections

“Observationally Consistent”

huge range !!! change in snowpack change in snowmelt runoff

7/9

SLIDE 8

Snowmelt R Runoff i in a a C Changing C Climate: Long ng-term O Outlook f for t the U Upper R Rio G Grande

1. C

Climate i is c changing i in w ways t that a affect t the R Rio G Grande, n now a and i in f future …. Temperature é, Snowpack ê …. No significant long-term trend in observed precipitation Only slight downward trend in total streamflow volume Shift in hydrograph toward earlier runoff peak

2. S

Snowpack ê is a associated w with R Runoff ê but p predictability o

Q i is d diminished …. Snowpack-based water supply outlooks are becoming harder …. Spring (post-SWE peak) precipitation is becoming more important .... Still anticipate lower flows from climate change as T é but uncertainty is large

8a/9

SLIDE 9

Snowmelt R Runoff i in a a C Changing C Climate: Long ng-term O Outlook f for t the U Upper R Rio G Grande

1. C

Climate i is c changing i in w ways t that a affect t the R Rio G Grande, n now a and i in f future …. Temperature é, Snowpack ê …. No significant long-term trend in observed precipitation Only slight downward trend in total streamflow volume Shift in hydrograph toward earlier runoff peak

2. S

Snowpack ê is a associated w with R Runoff ê but p predictability o

Q i is d diminished …. Snowpack-based water supply outlooks are becoming harder …. Spring (post-SWE peak) precipitation is becoming more important .... Still anticipate lower flows from climate change as T é but uncertainty is large

8b/9

SLIDE 10

Climate C Change a and t the R Rio G Grande

David S

Gutzler

wi with th Ne Nels Bj Bjarke, e, Sh Shale leene Chavarria a and Nolan T Townsend

University o

New M Mexico

gutzler@unm.edu

Elephant Butte Reservoir Jan 8, 2019

§ Observed and projected climate change § The problematic future of snowmelt runoff § Lower flows / Increased stress on water resources

1/9

Observed T Temperature a and Pr Precipitation i in N NM

updated from NM Water Supply Vulnerability Working Group (2015)

large,

no long-term trend (yet) lots of variability 1930 1970 2010

2/9

Streamflow a and S Snowpack i in t the R Rio G Grande H Headwaters

Rio Grande headwaters southern Colorado Del Norte Snow Course Sites Chavarria & Gutzler (2018)

~25% decrease 1958-2015

1958 1980 2000 2015

SWE (1 April) Q (Annual)

minimal trend (but earlier peak runoff)

3/9

Climate Pr Projections: D Declining Snow a and R Runoff

Brown & Mote (2009)

End-of-Century Snowpack Change

4/9

Milly et al. (2005)

Mid-Century Streamflow Change

current climate

3 different model projections (A1B-forced)

Hurd and Coonrod (2012)

Projected Rio Grande Hydrographs

Chavarria & Gutzler (2018) Bjarke & Gutzler (2019)

Increasing i importance o

Spring p precipitation f for R RG f flows

1 Apr SWE Based o

1 A Apr SW SWE

1987-2015 1958-1986 Apr-Jul Discharge [Mm3] 1 Apr SWE

In r recent d decades: Reduced r runoff p prediction s skill f from SW SWE

1951-80 1971-2000 1986-2015

5/9

Newer Pr Projections ( (CMIP5 P5, U US BoR BoR): ): Inflow i into EB EB Reservoir a at S San Mar Marcial al

1970 2020 2070

Observed and projected inflows into Elephant Butte Reservoir

climate model simulation

see Nolan’s poster

model output (natural flow)

models (1964-2013) models (2021-2070) Distribution of annual flows at San Marcial

Townsend & Gutzler (2019)

6/9

Model Pr Projections o

Snowpack a and S Snowmelt R Runoff in t the H Headwaters

Bjarke & Gutzler (2019)

CMIP5/BoR models that reproduce historical changes in SWE and Q project lower flows in future decades ... more consistent with previous projections

“Observationally Consistent”

huge range !!! change in snowpack change in snowmelt runoff

7/9

Snowmelt R Runoff i in a a C Changing C Climate: Long ng-term O Outlook f for t the U Upper R Rio G Grande

Climate i is c changing i in w ways t that a affect t the R Rio G Grande, n now a and i in f future …. Temperature é, Snowpack ê …. No significant long-term trend in observed precipitation Only slight downward trend in total streamflow volume Shift in hydrograph toward earlier runoff peak

Snowpack ê is a associated w with R Runoff ê but p predictability o

Q i is d diminished …. Snowpack-based water supply outlooks are becoming harder …. Spring (post-SWE peak) precipitation is becoming more important .... Still anticipate lower flows from climate change as T é but uncertainty is large

8a/9

Snowmelt R Runoff i in a a C Changing C Climate: Long ng-term O Outlook f for t the U Upper R Rio G Grande

Climate i is c changing i in w ways t that a affect t the R Rio G Grande, n now a and i in f future …. Temperature é, Snowpack ê …. No significant long-term trend in observed precipitation Only slight downward trend in total streamflow volume Shift in hydrograph toward earlier runoff peak

Snowpack ê is a associated w with R Runoff ê but p predictability o

Q i is d diminished …. Snowpack-based water supply outlooks are becoming harder …. Spring (post-SWE peak) precipitation is becoming more important .... Still anticipate lower flows from climate change as T é but uncertainty is large

8b/9

Nevertheless t this y year l looks b better t than 2 2018!

2018 2019 avg

N D J F M A M J Snowpack Rio Grande Headwaters

Northwestern Rio Grande in Colorado 50% %of max 30% 70% min 30-yr Forecast Point KAF avg KAF KAF KAF KAF avg

(APR-SEP)

NRCS Water Supply Outlook Based on 01 Apr 2019 forecast values

Current M Median O Outlook: 140% o

long-term t total d discharge

9/9