Innovative Approaches for Addressing Floods

Katie Hirschboeck & Kate Sammler

Laboratory of Tree-Ring Research

Tree-Ring DayEarth Science Week

March 29, 2010

Hirschboeck Research Themes:

Extreme High and Low Flow Years in Upper Colorado & Salt-Verde Basins based on Reconstructed Streamflow* 1521-1964

< 10th Percentile < 25th and ≥ 10th Percentile ≥ 25th and ≤ 75th Percentile > 75th and ≤ 90th Percentile > 90th Percentile

Upper Colorado River Basin

(UCRB) ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔

Salt -Verde -Tonto River Basin(SVT)

1520

1530

1540

1550

1560

1570

1580

1590

UC

RB

↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔

SV

T

1600

1610

1620

1630

1640

1650

1660

1670

1680

1690

UC

RB

↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔

SV

T

1700

1710

1720

1730

1740

1750

1760

1770

1780

1790

UC

RB

↔ * ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ * ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔

SV

T

1800

1810

1820

1830

1840

1850

1860

1870

1880

1890

* Reconstructed annual water year discharge

UC

RB

↔ HH years (high flow in both basins)

↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ LL years (low flow in both basins)

SV

T

LH = Low in UCRB / High in SVT

1900

1910

1920

1930

1940

1950

1960

HL = High in UCRB / Low in SVT (no occurrences)

Figure 15 – LL and HH water years with quantile time series

Extreme High and Low Flow Years in Upper Colorado & Salt-Verde Basins based on Reconstructed Streamflow* 1521-1964

< 10th Percentile < 25th and ≥ 10th Percentile ≥ 25th and ≤ 75th Percentile > 75th and ≤ 90th Percentile > 90th Percentile

Upper Colorado River Basin

(UCRB) ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔

Salt -Verde -Tonto River Basin(SVT)

1520 1530 1540 1550 1560 1570 1580 1590

UCRB↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔

SVT1600 1610 1620 1630 1640 1650 1660 1670 1680 1690

UCRB↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔

SVT1700 1710 1720 1730 1740 1750 1760 1770 1780 1790

UCRB↔ * ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ * ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔

SVT1800 1810 1820 1830 1840 1850 1860 1870 1880 1890

* Reconstructed annual water year discharge

UCRB ↔ HH years (high flow in both basins)

↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ ↔ LL years (low flow in both basins)

SVT LH = Low in UCRB / High in SVT

1900 1910 1920 1930 1940 1950 1960

HL = High in UCRB / Low in SVT (no occurrences)

Figure 15 – LL and HH water years with quantile time series

Tree Rings& Drought

Hydroclimatology

1670 = missing ringwide rings

shift to narrower rings

1670 = missing ring1670 = missing ringwide rings

shift to narrower rings

The “HIRSCHBO” LAB

Co-advising with Holly Hartmann:Jeannette EstesM.S. Hydrology & Water Resources

Volunteer: Nazanin BabamarandiFormerly: Iran MeteorologicalOrganization

Ela CzyzowskaPh.D. ProgramArid Lands ResourcesSciences

How can I remove these

trees?

Kate SammlerPh.D. ProgramSchool of Geography& Development

How would I classify THIS

flood!?

Jennifer (Welti) LeeM.S. Atmospheric

Sciencesin absentia

National Weather Service Forecaster, Hunstville AL

How are climate patterns & daily weather maps linked?

Ongoing collaboration:

Ashley ColesPh.D. ProgramUA School of

Geography&

Development

Why do people drive into

flooded washes?

Innovative Approaches for Addressing Floods

Katie Hirschboeck & Kate Sammler

Laboratory of Tree-Ring Research

Tree-Ring DayEarth Science Week

March 29, 2010

Beyond “Cuisinart” Hydrology:

EXTREME

MAKEOVER:

Southwest Climate

Edition

How can water managers better deal with events in the “tails” of streamflow probability distributions — both floods & droughts?

. . . By moving beyond conventional approaches . . . .

Statistically, EXTREME EVENTS are phenomena of the Lower & Upper Tails of Skewed Probability Distributions . . .

. . . are compelling benchmarks that aid in planning for future extreme LOW FLOW conditions using :

-- tree-ring reconstructions -- simulations-- scenario-building-- climate projection

modeling

For WESTERN WATER MANAGERS :

Water supply simulation based on extreme low flow sequences in the

paleo-record

STREAMFLOW RECONSTRUCTION for 1330-2005

Tree-Ring StreamflowReconstructions . . .

In contrast . . . FLOOD & WATERSHED MANAGERS are far more constrained in the ways they can incorporate climate change information operationally.

This is due to . . . .

-- the extreme, short-term, localized, and weather-based nature of flooding . . . .Photo by Ashley Coles

-- existing flood management policy and practices 100-Year Flood

Hazard Area

and . . . -- inconclusive evidence for increases in

extreme flooding in the U.S. :

“ There is no evidence of widespread or systematic increases in peak streamflows, although there is widespread evidence of increases occurring in annual low flows.”

Lins ( 2005)see also: Douglas et al., 2000; Lins and Slack 2005

LAND USE CHANGES = perceived as the more important issue

A Workshop on Global Change and

Extreme Hydrologic Events: Testing Conventional Wisdom

January 5, 2010 - January 6, 2010

Committee on Hydrologic Sciences

National Academy of Sciences

Information presented in an operationally useful format for flood & watershed managers

which describes how changes in the large-scale climatic “drivers” of hydrometeorological

extremes will affect flooding variability in SPECIFIC WATERSHEDS

What’s Needed:

Meteorological & climatological flood-producing

mechanisms operate at

varying temporal and spatial scales

FLOOD-CAUSING DRIVERS & MECHANISMS

What does it look like when classified hydroclimatically?

What kinds of storms produced the biggest floods?

Can we find out more about what drives this history of flooding?

FLOOD HYDROCLIMATOLOGY = classifying each flood in the record according to cause

As seen in a newspaper ad . . . .

“FLOOD PROCESSOR”

With expanded feed tube – for entering all kinds of flood data

including steel chopping, slicing & grating blades

– for removing unique physical characteristics, climatic information, and outliers

plus plastic mixing blade – to mix the populations together

Current practice analyzes floods using

“CUISINART”HYDROLOGY!

A Mixture of Flood Causes: Data from key flood subgroups may be

better for estimating the probability and type of extremely rare floods than a single “100-Year Flood” calculated from all the flood data combined!

Moving Beyond “Cuisinart” Hydrology . . . .

-- Useful for defining regions; -- Can then be used to estimate flow behavior in ungaged basins

(new USGS collaboration)

FLOODHYDROCLIMATOLOGY:

(1) Different types of FLOODS

(2) Different types ofSEASONAL FLOW REGIMES

Tropical Storm -related

Summer convective

Wintersynoptic (extreme )

Winter synoptic

(moderate)

From: Haney (2007) Southwest Hydrology

ConceptualEcological Modelfor a SouthwesternRiver Ecosystem

Flow regime is of central importance in sustainingthe ecological integrity of flowing water systems

Ecosystem Services Analysis of Climate Change and Urban Growth in the Upper Santa Cruz Watershed; the Santa Cruz Watershed Ecosystem Portfolio Model (SCWEPM) A decision support tool to mimic ecosystem services and alternative scenarios based on predictions of urban development and climate change

.

Based on USGS “peaks-above-base” record (annual & partial series)

PURPOSE: to determine hydroclimatic context for causes of floods in AZ watersheds

Flood Hydroclimatology Database

Model runs to link surface hydrology with scenario-

driven atmospheric circulation

Increasingly Important Research Needs:

DOWNSCALING-- clearly communicate accuracy in downscaled model results

-- don’t oversell the degree of precision

-- “scaling up from local data is as important as scaling down from globally forced regional models.”

-- regionally tailored indices may be better than the latest “index-de-jour”

Process studies at the watershed scale to specify climate linkages

Coupled with PROCESS-SENSITIVE

UPSCALING

WHAT WILL THE FUTURE HOLD?

. . . will climatic change

make floods more extreme? more

frequent?

or will they get smaller? more

frequent? less

frequent?

Some Important Flood-Generating Tropical Storms

Tropical storm Octave Oct 1983

(2) A Change in Frequency or Intensity of Tropical Storms?

(1) A Northward Shift in Winter Storm Track?

Roosevelt Dam Jan 1993 Winter flooding

on Rillito in Tucson

(3) A More Intense Summer Monsoon?

RillitoJuly 2006

THANK YOU!