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CUAHSI Fall 2004 Vision Paper Cyberseminar Series
www.cuahsi.org
CUAHSI Fall 2004 Vision Paper Cyberseminar Series
www.cuahsi.org
Leal Leal MertesMertesComing to you from Coming to you from Santa Barbara, CASanta Barbara, CAOctober 5October 5thth, 2004, 2004To begin at 3:05 ETTo begin at 3:05 ET
FloodplainsFloodplains
Welcome to the 3Welcome to the 3rdrd Semester of Semester of CUAHSI CUAHSI
Education and Outreach Education and Outreach Distinguished LecturesDistinguished Lectures
Host: Jon DuncanHost: Jon DuncanCUAHSI Communications CUAHSI Communications
Director
Problems? Send a chat to Host
Feedback? Please send an email to [email protected]
Director
The Presentation can be downloadedFrom www.cuahsi.org
Fall ScheduleFall ScheduleScaling and Hydrologic ModelingScaling and Hydrologic Modeling--
Geoff Geoff ThyneThyne, CSM. October 14, CSM. October 14thth
Intensively Managed LandscapesIntensively Managed LandscapesBill Simpkins, ISU. October 19Bill Simpkins, ISU. October 19thth
EcohydrologyEcohydrology of Semiof Semi--Arid EnvironmentsArid EnvironmentsBrent Newman, LANL. October 21Brent Newman, LANL. October 21stst
Go to CUAHSI website for complete calendar, links Go to CUAHSI website for complete calendar, links to papers, presentations, and discussion forumsto papers, presentations, and discussion forums
FLOODPLAINSCUAHSI Cyberseminar:
October 5, 2004Noon – Pacific Time
Leal A.K. MertesDepartment of Geography
UCSB
FLOOD TEAM:Jean Bahr - UWiscMartin Doyle - UNCLeal Mertes - UCSB
Andrew Miller - UMarylandGeoff Poole - UGAKen Potter - UWisc
Jim Smith - PrincetonRip Sparks - UIllinoisEmily Stanley - UWisc
Landsat
OUTLINEOUTLINE1st Principles– Scale– Geomorphology– Hydroclimatology– Habitat
Human ImpactResearch Agenda– Flood Discharge
Urban Watersheds – Flood Frequency– Inundation Hydrology
Water Distribution – Floodplain Capacity & ModellingPerirheic Mixing - SedimentHyporheic Exchange – Thermal
– Geomorphic Template – Heterogeneity & Landscape Arrangement– Biogeochemistry – Nitrogen Cycle– Biology – Flow Reversals
Summary – Societal Importance– Enoughness?– Function Compression
11stst PRINCIPLES PRINCIPLES -- Spatial Scale:Spatial Scale:Riverine Geomorphology & EcologyRiverine Geomorphology & Ecology
Watershed101 km2-106 km2
Valley/Reach100 m-104 m
Channel Unit100 m-103 m
Stream Bed100 cm-105 cm
(Poff, 1997)
11stst PRINCIPLES PRINCIPLES –– Hydroclimatology:Hydroclimatology:Spatial & Temporal ScalesSpatial & Temporal Scales
(after Hirschboeck, 1988)
Watershed101 km2-106 km2
Valley/Reach100 m-104 m
Channel Unit100 m-103 m
Stream Bed100 cm-105 cm
11stst PRINCIPLES PRINCIPLES -- Flood Flood Hydroclimatology & BiomesHydroclimatology & Biomes
(hydroclimatology after Hayden, 1988 - as published in Poff et al. 2001)
HUMAN IMPACT HUMAN IMPACT -- DamsDams
100 200 3000
Duration
Reversal
Rate ofrise
Rate of fall
Day of the yearIndicators of Hydrologic Alteration (IHA, Richter et al. 1996): 42 biologically meaningful hydrologic parameters for eight gage sites along the Illinois River.
“Ideal” (1887)
HUMAN IMPACT –Geomorphic simplification of floodplains –
Willamette River and floodplain
1854 1910 1967
(Sedell and Froggatt, 1984)
RESEARCH AGENDARESEARCH AGENDA– Flood Discharge
Urban Watersheds – Flood Frequency– Inundation Hydrology
Water Distribution – Floodplain Capacity & Modelling
Perirheic Mixing - SedimentHyporheic Exchange – Thermal
– Geomorphic Template – Heterogeneity & Landscape Arrangement
– Biogeochemistry – Nitrogen Cycle– Biology – Flow Reversals
FLOOD DISCHARGE FLOOD DISCHARGE --QuestionsQuestions
What is the relationship between the channel – floodplain system and the history of storm events in an urban drainage basin?What are the dynamic processes associated with flooding at the watershed scale, how do floods respond to the interplay between hydrometerology, geology, topography, and anthropogenically modified features of the landscape?
FLOOD DISCHARGE FLOOD DISCHARGE --AssertionsAssertions
Floods are both spatially and temporally complex and notoriously difficult to measureStage/discharge relationships are not necessarily single-valued; can get looped or hysteretic rating curves when following rising and falling limbs of the same eventCan get substantial lateral water-surface gradients across the floodplain with changing stage during a floodCan also get backwater effects, sometimes including reverse flow at confluences and constrictions; or associated with transient obstructions like debris jams
FLOOD DISCHARGE – Urban WatershedsUrban channel/floodplain systems are not necessarily simple; channels and riparian zones may exhibit strongly heterogeneous characteristics over short distances.
Flood of June 13, 2003
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
6/13/03 15:00 6/13/03 17:00 6/13/03 19:00 6/13/03 21:00 6/13/03 23:00 6/14/03 1:00 6/14/03 3:00 6/14/03 5:00
Dis
char
ge in
ft3/
s
Whitemarsh Run at FullertonWhitemarsh Run at White Marsh
(Whitemarsh in Baltimore region watershed)
The Urban Hydrologic SystemThe Urban Hydrologic System(courtesy of Ken Belt, U.S. Forest Service)(courtesy of Ken Belt, U.S. Forest Service)
Water Supply Pipes
WastewaterConduits
Stormdrains
GroundwaterFlow Paths
Septic Systems
Impervious Surfaces
Artificial Channels
INUNDATION HYDROLOGY INUNDATION HYDROLOGY --Watershed Structure &Watershed Structure & the the
Floodplain PatchFloodplain Patch
Variable contributions from sourcescan produce differentinundation patterns.
SOURCES of WATERIN = main channel input
TR = major tributaryL = local tributary
GW = groundwater/hyporheic waterP = local precipitation
INUNDATION HYDROLOGY INUNDATION HYDROLOGY --Floodplain Capacity: Distribution Floodplain Capacity: Distribution
of Floodplain Waterof Floodplain WaterHow much water in a stream ever resides on the floodplain?What is the frequency distribution of inundation depths and areas?What is the frequency distribution of residence times of water that reaches floodplain surfaces?How is this residence time distributed across a watershed?
INUNDATION HYDROLOGYINUNDATION HYDROLOGY-- Distribution Distribution of recurrence intervals as a measure of capacity of recurrence intervals as a measure of capacity
for river reaches (for river reaches (WoltemadeWoltemade 1993)1993)
INUNDATION HYDROLOGY - GW & HW Model Results
for Flathead River
radius = degree of variationin GW vector over 6-month simulation
direction & magnitude of GW flow vectorupwelling (white) & downwelling(black); radius = vertical flux
INUNDATION HYDROLOGY INUNDATION HYDROLOGY --Surface Water Mixing: PerirheicSurface Water Mixing: Perirheic
INUNDATION HYDROLOGY INUNDATION HYDROLOGY --Surface Mixing: Monitoring SedimentSurface Mixing: Monitoring Sediment
R. Negro + R. Solimões = Amazonas
Landsat 321 = RGB August 15, 1988
INUNDATION HYDROLOGY INUNDATION HYDROLOGY --Perirheic Mixing on Amazon FloodplainPerirheic Mixing on Amazon Floodplain
~2 km
perirheos
INUNDATION HYDROLOGY INUNDATION HYDROLOGY --SubSub--Surface Water Mixing: HyporheicSurface Water Mixing: Hyporheic
Channel
Riparian Zone
HyporheicPhreatic
Streambed Paleochannel
AlluvialAquifer
INUNDATION HYDROLOGY –Hyporheic Exchange: Thermal Monitoring
Temperature patterns from data loggers (Arrigoni 2004)
°°
°
20
21
22
23
24
25
26
27
28
1 3 5 7 9 11 13 15 17 19 21 23Time (hours)
Mea
n te
mpe
ratu
re (
C) a
cros
s sa
mpl
ing
per
iod
river (downwelling)
ground water (upwelling)
°
upwelling
downwelling
INUNDATION HYDROLOGY –Hyporheic Exchange: Thermal Monitoring
Fine Temporal Monitoring with Field Instruments(Arrigoni 2004)
15
17
19
21
23
25
27
29
31
20-Jul 22-Jul 24-Jul 26-Jul 28-Jul 30-Jul 1-Aug 3-Aug 5-Aug 7-Aug 9-Aug 11-Aug 13-Aug
Wat
er T
empe
ratu
re (°
C)
Downwelling Predicted
Upwelling Predicted
Rain
INUNDATION HYDROLOGY –Thermal Monitoring with Forward-Looking Infrared Radiometer (FLIR)(Torgersen et al. 2001 as published in Mertes et al. 2004)
GEOMORPHIC TEMPLATE –Measuring Heterogeneity, i.e.
Landform VariabilityJökulhlaup on Skeiðarársandur, Iceland
November 5-7, 1996 (Guðmundsson & Sigurðsson, 1996)
GEOMORPHIC TEMPLATE –Measuring Heterogeneity, i.e.
Landform VariabilityJökulhlaup on Skeiðarársandur, Iceland
Iceberg Landforms
(Guðmundsson & Sigurðsson, 1996)
GEOMORPHIC TEMPLATE –Measuring Heterogeneity, i.e.
Landform VariabilityJökulhlaup on Skeiðarársandur, Iceland
Channel Landforms
(Iceland Calendar 1997)
GEOMORPHIC TEMPLATE –Measuring Heterogeneity, i.e.
Landform VariabilitySandur Variability Map Based on Digital Elevation
Map from Airborne Radar Altimetry (Smith et al. 2000)
(J. Mason)
GEOMORPHIC TEMPLATE GEOMORPHIC TEMPLATE ––Human Impact: Mesopotamian MarshesHuman Impact: Mesopotamian Marshes
GEOMORPHIC TEMPLATE GEOMORPHIC TEMPLATE ––Landscape Landscape Re Re –– ArrangementArrangement
Mesopotamian Mesopotamian MarshlandsMarshlands
From 1970s to present, marshlands re-engineered and drained. White areas on 3 images (Landsat – 77 & MODIS – 02 & 04) show location of open water during “flood” season. Grey tones show wetland vegetation. Renewed water releases due to 2003-2004 Iraqi conflict show impact of drainage engineering on geomorphic template &, therefore, inundation pattern.
BIOGEOCHEMISTRY – Nitrogen Cycle Nitrate transport and transformation in
groundwater beneath floodplains
How can floodplain preservation and restoration contribute to reducing nitrogen export from agricultural lands?What combinations of subsurface hydrostratigraphy, surface topography, vegetation, and inundation patterns create conditions that promote subsurface denitrification?What field monitoring strategies are necessary for and most effective at identifying zones of denitrification and quantifying denitrification rates in the subsurface?
BIOGEOCHEMISTRY – Nitrogen CycleBasic requirements for denitrificationa) Microbial population of denitrifiersb) Suitable Redox conditions (low Dissolved Oxygen - DO)c) Electron donor (organic carbon or other reduced species)
Floodplain zones in which these conditions are expected include shallow wetland soils and zones of hyporheic exchange
Hyporheic Zone
Shallow wetland soils
Transient water levels may create deeper mixing zone in which organic carbon moved downward with infiltrating water serves as electron donor for reduction of nitrate from upland agricultural areas.
Can floodplain complexity generate additional zones of denitrification?
Local topography creates complex flow paths
BIOGEOCHEMISTRY –Nitrogen Cycle
BIOGEOCHEMISTRY – Nitrogen CycleGreater potential for denitrification in groundwater beneath floodplains with complex topography and frequent inundation compared to those with more uniform topography and steady water levels or flowpaths
RESEARCH STRATEGY– Comparative studies in floodplains with
varying degrees of physical and hydrologic complexity and affected to varying degrees by human or other disturbance
– Integration of stratigraphic, hydrologic, geochemical, vegetation and microbiologic data
– Monitoring over sufficient time to characterize effects of variations in flow paths and nitrogen sources at seasonal and inter-annual scales.
BIOGEOCHEMISTRY – Scale Issues
?Need for understanding
nutrient dynamics at the scale of the problem
-Characteristic small-scale variation of floodplains
-Small-scale of measurement
versus
# of
sam
ples
DEA (ng N/g soil/hr)0 5 10 15 20 25 30 40 50 75 100150
0
25
50
75
100
Denitrification 19990 25 50 75 100 125 150
Den
itrifi
catio
n 20
00
0
50
100
150
200
250
300
BIOLOGY – Human Impact: Flow reversals
100 200 3000
Moist soil plant growing season
Spikes
Duration
Reversal
Rate ofrise
Rate of fall
Day of the year
Effects on Plants
0 100 200 300Day of Year
130
132
134
136
Riv
er L
evel
(met
ers
abov
e m
sl)
Pre-dam (1887)
Post-dam (1987)
natural dryseason
From Technical support of public decisions to restore floodplain ecosystems:a status report on the Illinois River project, 2000
BIOLOGY – Human Impact: Flow reversals
Altered Water Regime
Biomass
Plant height
g
End of growing season
With pre-dam (1887) hydrograph
BIOLOGY – Human Impact: Flow reversals
g
Biomass
Plant height
End of growing season
With post-dam (1987) hydrograph
BIOLOGY BIOLOGY –– Human Impact: Flow reversals
Societal Importance: Societal Importance: Striking a BalanceStriking a Balance
Natural Goods & Services
Natural Goods & Services
Engineered System Services
Engineered System Services
Drinking WaterNutrient Retention
FisheriesFlood MitigationWildlife Habitat
TransportationHydropowerAgricultureRecreation
SUMMARY – Societal ImportanceThe value of nature and the nature of value.
“Identify the production functions” (Daily et al.)
N removal/uptakeFlood reductionProduction of fish, wildlifeMaintenance of biodiversity“Serenity”
“Enoughness” questions – How much (e.g., in-stream flow)?
Arrangement on landscape – Upstream-downstream; lateral