Corps of Engineers

BUILDING STRONG®

Climate Change / Adaptation

Jerry W. Webb, P.E., D.WREPrincipal Hydrologic & Hydraulic EngineerHydrology, Hydraulics & Coastal Community of Practice LeaderUS Army Corps of Engineers, Headquarters Jerry.w.webb@usace.army.mil

Dam Safety WorkshopBrasília, Brazil20-24 May 2013

US Army Corps of Engineers Civil Works Missions: Water Resources Management

2NAVIGATION

Navigation

Flood and Coastal

Storm Risk Reduction

Ecosystem Restoration

Hydropower

Water Supply

Recreation

Emergency Management

Regulatory

WATER

CARBONClimate change mitigation is

about

Climate change adaptation is

about

USACE Climate Adaptation Mission:

To improve resilience and decrease vulnerability to the

effects of climate change and variability

Bill Byrne, MA F&W

USACE Climate Adaptation Policy June 2011 Integrate climate change

adaptation planning and actions into USACE missions, operations, programs, and projects

Use the best available and actionable climate science and climate change information at appropriate level of analysis

Consider climate change impacts when undertaking long-term planning, setting priorities, and making decisions

http://www.corpsclimate.us/adaptationpolicy.cfm

Climate Change, Extreme Events and Water Infrastructure

Extreme events and increasing variability increase water resources vulnerability►Public health and safety►Economic development►Environmental

sustainability

National Geographic

Extremes and Surprises Add Complexity “… the biggest issue is not a failure to envision

events that may be surprising.”

“It is a failure to decide which ones to act upon, and to what degree.”

“That failure results, at least partially, from the fact that there is no systematic mechanism in place…. to help decide which events to act upon aggressively, which to treat to a lesser degree, and which to ignore, for the time being.”

US DoD Defense Science Board: Capability Surprises

7

0 10 20 30 40 50 60 70 80 90 100

Years

Increasing Severity of Climate Impacts

Infrastructure planned and built with past climate and weather in mind may not be adequate for future resilience and operation.

Planning

Engineering and Design

Construction

Infrastructure Service Life

In Service

After United States Ports: Addressing the Adaptation Challenge, Mr. Mike Savonis

Water Resources Infrastructure Long Service Life and Long Lead Time

DIS

ASTE

R

Adaptation to Climate Change and Extreme Events is a Continuum

Analyses, Operational Measures,

Anticipatory Engineering

Policy, Structural Measures, Post-Event

Adaptation

Preparedness, Response, Recovery

Pakistan Siachen Glacier SME

Support April 2012

Key 2011/2012 ResponsesQueensland, Australia

Flood - Jan 2011Christchurch, New Zealand

Earthquake - Feb 2011

FEST Deployments Jan – Mar 2011 &

OEF/OND

Japan EQ & Tsunami - Mar 2011

MS FloodsMay 2011

Fort CrowderLogistics Point

RRCC VII

Joplin, MO (RFO)

Joplin, MOTornado - June

2011 MO River Flood

Jun/Jul 2011

Thailand Flood - Nov 2011

Northeast Snow StormOct 2011

Hurricane Irene

Aug 2011

Tropical Storm LeeSep 2011

Souris River Flood

Jun/Jul 2011

Severe Weather – Midwest

Mar 2012

AL & MS TornadosApr 2011

2012 Drought

Duluth, MN Flood

Derecho StormsJUN-JUL 12

Kootenai River, 8.96 million acres, 2 countries, 2 states75% in BC, 21% in MT, 6% in ID

Koocanusa Reservoir

Libby Dam

Bonners Ferry

Queens Bay at Kooteney Lake

Corra Linn Dam

To the Columbia River

Kootenai River Basin2012

Quick Review of Using Scenarios in Support of

Climate Change Analyses With Emphasis on Sea-Level

Change

Changing Paradigms: From Equilibrium to Dynamic

Hurricane Katrina► Internal and external reviews

following Hurricane Katrina (IPET, HPDC, ASCE, National Academies, and others) demonstrated that we need to incorporate new and changing conditions, both foreseen and surprise, into USACE projects and programs

Stationarity► Climate change undermines a

basic assumption that historically has facilitated management of water supplies, demands, and risks.’ Milly et al 2008

Fundamental Change in Approach to Future Conditions

Historically, we identified a single most likely future condition and based our without-project (baseline) analyses on this condition

Now, we understand that there can be multiple plausible futures, each representing a different combination of physical processes, social and political values, and economic conditions, among other factors

In particular, for hydrology, we can no longer rely on the assumption of stationarity, where statistical properties of hydrologic variables in future time periods are assumed to be similar to past time (i.e., future variation in the same range as in the past)

Universe of Futures

Carter et al (2007)

“We need to research all the potential outcomes, not try to guess which is likeliest to occur.”

“Probability in the natural sciences is a statistical approach relying on repeated experiments and frequencies of measured outcomes, in which the system to be analysed can be viewed as a ‘black box’. Scenarios describing possible future developments in society, economy, technology, policy and so on, are radically different.”

Why Scenarios? Scenarios are appropriate when uncertainties are large,

the consequences are significant, and outcomes cannot be bounded

Scenarios are intended to illuminate potential vulnerabilities to the range of outcomes

Once we've identified how and where we are vulnerable, we can evaluate whether we are equipped to deal with the vulnerabilities

Next, we address trade-offs between costs and other effects under each option to address vulnerabilities

Probabilities simplify the math, but don't really help us to explore these kinds of issues – instead, probabilities make it easy for us to ignore these issues

Why Scenarios for Sea-Level Change? Remember, scenarios are appropriate when

uncertainties are large, the consequences are significant, and outcomes cannot be bounded

Sea level change (and more broadly, broader climate change) meets the first and last of these three conditions.

For the second condition, we use sensitivity testing to determine the potential consequence of sea-level change, and the sensitivity test guides our scope of study and the rigor of the scenario analysis

EC 1165-2-211 Incorporating Sea Level Change Considerations in Civil Works Programs

Three estimates of future SLC must be calculated for all Civil Works Projects within the extent of estimated tidal influence:

► Extrapolated trend► Modified NRC Curve 1► Modified NRC Curve III

These curves are scenarios based on different assumptions about physical processes and causes without specific attributions of likelihood

As a result, the scenarios

used in the EC represent multiple plausible futures

Comparison of EC 1165-2-211, IPCC, and Other Recent Research

~ EC

Does not include changes in sea level resulting from changes in the large ice sheets covering Greenland and Antarctica

Examples of Climate Change Adaptation

Example: Mississippi Watershed Extremes

60%

40%

Ohio River

Upper Mississippi andMissouri RiversCombined

Flow Contribution to Lower Mississippi River

• Flood of 2011 tested system• Huge volume, long duration, snowmelt and rainfall• System performed as designed

• Flood risk reduction systems were operated at their maximum capacity, some for the first time ever

• Design demonstrated incredible foresight

• Drought of 2012 tested system again• Impacts to navigation, water supply, recreation, energy

production

• 2011 and 2012 highlighted resilience to extreme events

Mississippi River Extremes

Columbia River Treaty 2014/2024 Climate Change Impact Studies

2020s

2040s

2080s

°C

* Compared with 1970-1999 averageMote and Salathé, 2010

+2.0ºF (1.1-3.4ºF)

+3.2ºF (1.6-5.2ºF)

+5.3ºF (2.8-9.7ºF)

°F

Choice of emissions scenario matter more after 2040s

Projected Increases in Annual Temperature

HH

* Compared with 1970-1999 average

Changes in annual precipitation averaged over all models are small but some models show large seasonal changes, especially toward wetter autumns and winters and drier summers.

Mote and Salathé, 2010

Projected Changes in Annual Precipitation HH

As the West warms,spring flows rise and summer flows drop

Stewart IT, Cayan DR, Dettinger MD, 2005: Changes toward earlier streamflow timing across western North America, J. Climate, 18 (8): 1136-1155

Trends in Fractional

Streamflow

HH

April 1 SWE (mm)

20th Century Climate “2020s” (+1.7 C) “2040s” (+ 2.25 C)

-3.6% -11.5%

-21.4% -34.8%

Changes in Simulated April 1 Snowpack

Canadian and U.S. portions of the Columbia River basin

(% change relative to current climate)

+1.7 °C +2.3 °C

• Warming temperatures will increasingly stress coldwater fish in the warmest parts of our region– A monthly average air temperature of 68ºF (20ºC) has been used as an

upper limit for resident cold water fish habitat, and is known to stress Pacific salmon during periods of freshwater migration, spawning, and rearing

Temperature thresholds for coldwater fish in freshwater

The Dalles Regulated, Median year at The Dalles

Wet has more volume Nov-May

Peak is slightly earlier, but similar

Base has noticeable more volume in Jul-Sep

Average HydSim Outflows at the Dalles

0

50000

100000

150000

200000

250000

300000

350000

400000

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Qout

The Dalles - Average Outflow - All Years

Base 2A-TC-45 Dry Case Wet Case

Note reduced summer flows

Early April drop attributed to reduction in Arrow outflows as defined by Treaty operations

Note significant increase in winter

flows

Payne, J.T., A.W. Wood, A.F. Hamlet, R.N. Palmer, and D.P. Lettenmaier, 2004, Mitigating the effects of climate change on the water resources of the Columbia River basin, Climatic Change, Vol. 62, Issue 1-3, 233-256

Flood Control vs. Refill Balance between flood protection and reliability of refill

is crucial in the Columbia Basin. As peak flows move earlier in the year

► flood evacuation schedules may need to be revised • To protect against early season flooding • To begin refill earlier to capture the (smaller) spring

freshet. Model experiments (see Payne et al. 2004) have shown

that moving flood evacuation two weeks to one month earlier in the year helps mitigate reductions in refill reliability associated with streamflow timing shifts.

Implications for Transboundary Agreements Canadian Snowpack is less sensitive to warming then in

U.S. portion of Columbia basin► Streamflow timing shifts will also be smaller in Canada.

Over the next 50 years or so, Canada will have an increasing fraction of the snowpack contributing to summer streamflow volumes in the Columbia basin.

These differing impacts in the two countries have the potential to “unbalance” the current coordination agreements, and will present serious challenges to meeting instream flows on the U.S. side.

Changes in flood control, hydropower production, and instream flow augmentation will all be needed.

Long-range planning is needed to address these issues.

Other Implications of Climate Change

Bulletin 17B Revision

• Previous Wording for “Climatic Trends:”► “There is much speculation about climatic changes. Available evidence indicates that major changes occur in time scales involving thousands of years. In hydrologic analysis it is conventional to assume flood flows are not affected by climatic trends or cycles. Climatic time invariance was assumed when developing this guide.”

Bulletin 17B Revision

• Revised Wording for Climate Paragraph:► “There is much speculation about changes in flood risk over time. Available evidence indicates that major changes may be occurring over decades or centuries. While time invariance was assumed when developing this guide, where changes in climate and flood risk over time can be accurately quantified, the impacts of such changes should be incorporated in frequency analysis by employing time-varying LP3 parameters or using other appropriate and statistically justified techniques. All such methods need to be thoroughly documented and justified.”

Dam Safety Implications

Changes to storm types and magnitudes

Changes to runoff characteristics

Changes to calculations of Probable Maximum Precipitations – Dew Point alterations

--

Example Effects from Regional Precipitation Shifts

IPCC AR4 model CCSM3

► South regions drier during growing seasons, reducing agricultural productivity

► Extreme storms affect Central America and the Caribbean more than elsewhere

► Shifts in wet/dry seasonality

Graphic from Ganguly et al., (ORNL) produced for backing the QRD 2009. http://www.ornl.gov/knowledgediscovery/QDR/

2050 A1FI Drought Index

LEARNING OBJECTIVES

Using the course manual, references and lecture notes, the student will be able to understand hydrologic and hydraulic aspects of dam safety program. After this presentation, the student will be familiar with concepts, terminology and inter-relationships between hydrologic, hydraulic and water management considerations essential in the engineering analysis associated with the administration of the USACE Dam Safety program.

QUESTIONS