Innovative Approaches for Addressing Floods Katie Hirschboeck & Kate Sammler Laboratory of Tree-Ring Research Tree-Ring Day Earth Science Week March 29, 2010

Hirschboeck Research Themes:

The “HIRSCHBO” LAB Co-advising with Holly Hartmann: Jeannette Estes M.S. Hydrology & Water Resources Volunteer: Nazanin Babamarandi Formerly: Iran Meteorological Organization Ela Czyzowska Ph.D. Program Arid Lands Resources Sciences How can I remove these trees? Kate Sammler Ph.D. Program School of Geography & Development How would I classify THIS flood!? Jennifer (Welti) Lee M.S. Atmospheric Sciences in absentia National Weather Service Forecaster, Hunstville AL How are climate patterns & daily weather maps linked? Ongoing collaboration: Ashley Coles Ph.D. Program UA 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 Day Earth 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 Tree-Ring Streamflow Reconstructions...

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, 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)

FLOOD HYDROCLIMATOLOGY: (1) Different types of FLOODS (2) Different types of SEASONAL FLOW REGIMES Tropical Storm -related Summer convective Winter synoptic (extreme ) Winter synoptic (moderate)

From: Haney (2007) Southwest Hydrology Conceptual Ecological Model for a Southwestern River Ecosystem Flow regime is of central importance in sustaining the 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? Rillito July 2006

THANK YOU!