01 Fluvial Systems 2014 Runoff Tracer

Fluvial Solute and Sediment Transport

Particulate Transport in River Catchments

Reinhard Bierl & Sabine Keßler

WiSe 2014/15

[email protected]

Room H 226

Introduction

Part 1: Solutes and natural tracers

• Introduction

• Runoff generation processes

• Abundance of natural tracers, properties, analysis, case studies

– Hydrochemical tracers

– Environmental isotopes (stable and radioactive isotopes)

• Methods

– Mixing, hydrograph separation

– Determination of mean residence time

2

Introduction

• Books: Leibundgut, C., Maloszewski, P. and Külls, C. (Eds.) 2009: Tracers in Hydrology, Wiley-

Blackwell. Kendall and McDonnell (Eds.) 1998: Isotope Tracers in Catchment Hydrology, Elsevier. Kaess (Ed.), 1998: Tracing Techniques in Geohydrology, Balkema. Mook, W. G. 2001: Environmental Isotopes in the Hydrological Cycle- Principles and

Applications. UNESCO-IAEA, IHP Publications. (free at the web!) Aggarwal P.K., Gat J.R., Foehlich K.F.O., 2005: Isotopes in the water cycle. Springer.

• IAEA web pages: Isotope Hydrology Section: http://www-naweb.iaea.org/napc/ih/index.html Isotope Hydrology Information System and Global Network for Isotopes in Precipitation:

http://www-naweb.iaea.org/napc/ih/IHS_resources_gnip.html Isotope Hydrology Information System and Global Network for Isotopes in Rivers:

http://www-naweb.iaea.org/napc/ih/IHS_resources_gnir.html• Isotope Geochem web pages with e-mail discussions:

http://list.uvm.edu/cgi-bin/wa?A0=ISOGEOCHEM

Sources of course notes and further information

3

Introduction

1. Introduction to the tracer hydrological approach

2. Brief history of tracer hydrology (artificial tracers)

3. Natural tracers vs. artificial tracers

Objectives of this lecture

4

Discharge

Water quality

Isotopes

Geoelectric

Geoseismic

Sprinkling ExperimentsTracer tests

Soil and

groundwater

… and modelling!

Experimental Investigations

Different ways to examine flow paths and residence times

5

What are tracers?

• Tracers are natural or artificial substances / species, which can be detected at very low rates

• They are used in hydrology to identify flow pathways, source areas and residence times of water

• They can also be used to assess the vulnerability of a hydrological system, and to estimate solute or contaminant transport

Basic definitions

6

Hydrologicalsystem

Input Output

Convergence approach

Underlying theory applied to tracer hydrology

Precipitation RunoffEnergy ET

Tracer input Tracer output

7

lateraldischarge

lateral discharge

Why tracers?

Hydrological questions that tracer can help to address

8

Why tracers?

• Where does runoff originate in a catchment?

• How long has water resided in different hydrological storages?

• How fast does water move in different hydrological storages (subsurface, rivers, lakes, glaciers etc.)?

• How does groundwater and surface water interact (river bank filtration, groundwater upwelling etc.)?

• What biogeochemical processes affect water chemistry?

• What are the rates of these biogeochemical processes?

• Engineering questions: leakage of pipes, tanks etc.? Hydraulic tests of wells etc.?

… add some to this list!

Hydrological questions that tracer can help to address

9

Why tracers?

The water cylce

10

(Dyck 1976)

Why tracers?

Close interconnection of energy-, water-, solute and particle cycles

11

History of tracer hydrology

Horizontal distance

about 11.7 km

Example 1: Disappearance of the Danube

12


Hydrology River Rhine and Danube (Southern Germany)

13


• Injection of

– 600 kg oil (!)

– 10 tons salt

– 10 kg uranine (fluorescence dye)

• All tracers were found about two days later

• Flow velocity > 200 m/h

• Salt recovery rate about 93 % (approx. 9.3 tons)

Knoop 1877: Investigation of the flow paths

14

Time after injection (hours)

‘Gravimetric’ chloride evidenceusing AgNO3 AgCl


Knoop 1877: Investigation of the flow paths

15

Example 2: The Loue spring in France: One of the first tracer application in history

Absinth production


16

More modern history

What is often taught in Engineering Hydrology

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60Time

Str

eam

Dis

ch

arg

e

Quickflow, Stormflow

Baseflow

Quick flow

Assumed to be precipitation

Slow flow

Assumed to be Groundwater/

Interflow

(McDonnell 2007) 17

What really happens…

The benchmark paper: Sklash & Farvolden (1979)

(Sklash & Farvolden 1979) 18

What tracers exist?

Natural tracers vs. artificial tracers

Natural input Artificial injection

19

What tracers exist?

• Spatially distributed and continuous marking through the precipitation

• Use at larger scales,compared to artificialtracers

• Spatio-temporal variability of the input is difficult to observe

Examples: Natural tracers natural input

20

What tracers exist?

Results:Different isotope concentrations in rivers and quantification of mixing

21

What tracers exist?

• Tracer input at a specific time, at a specific location during a specific hydrological situation

• Tracing of a given water volume

• Spatial and temporal limitations

• Difficult to generalize(‘non representativity’ of the time, location or situation)

Examples: Artificial tracers - artificial tracer injection

22

What tracers exist?

Results: Tracer breakthrough curve and tracer recovery rate

Tracerdurchgangskurve

0

5

10

15

20

25

30

0 7 14 21 28 35 42 49 56 63

Tage nach Einspeisung

C [

mg

/m³]

0

10

20

30

40

50

60

70

80

90

100

pro

zen

tuale

r A

nte

il d

er

au

sg

etr

ete

nen

Tra

cerm

en

ge

t1

t2

t3 t0 = Einspeisung

t1 = erstes Auftreten des Tracers

t2 = Peak (C max)

t3 = Medianwert (50%)

t4 = Ende Tracerdurchgang

Fließgeschwindigkeit = x / t [m/d]

Bsp. x = 80 m 80/8 = 10 m/d mittlere Fließgeschwindigkeit

t3 = 8 Tage

t0

t4

t0 = injection

t1 = first detection of tracer

t2 = peak of tracer concentration

t3 = median (50% tracer breakthrough

t4 = end of tracer break through

Accum

ula

ted tra

cer

bre

akth

rough

[%]

Time after injection [days]

23

What tracers exist?

Available Tracers Natural Tracers Artificial Tracers

Environmental isotopes Radioactive Inactive Stable Tritium 3H Soluble substances Drifting substances

Deuterium 2H Sodium-24 24Na Salts Lycopodiumspores in different colours

Oxygen-18 18O Chromium-51 51Cr Na+ Cl- Fluorescent particles Cobalt-58 58Co K+ Cl- Bacteria Carbon-13 13C Bromine-82 82Br Li+ Cl- Viruses Helium-3 3He Iodine-131 131I HBO2 Fungi Sulphur-34 34S Gold-198 198Au

Radioactive Activatable Fluorescence tracers Special Tritium 3H Bromine Uranine Magnetic tracers Indium Eosine Carbon-14 14C Manganese Amidorhodamines Silicium-32 32Si Lanthan Rhodamines Chlorine 36Cl Dysprosium Naphtionate Argon-37 37Ar Pyranine Krypton-81 81Kr Tinopale Krypton-85 85Kr Flavines

Chemical components Conductivity µS /cm Sodium Na Others eg. Si,...

Pollution Tracers e.g. Chloride, heavy metals, detergents, radioactive substances, FCKW, 222Rn, etc.

(Leibundgut 2002) 24

Tracerinput

Longitudinal

dispersion

What tracer methods exists?

Example: Tracer transport in porous media

What controls the tracer transport in the system?

• Convection

• Dispersion

• Diffusion

• Sorption

• Mixing

25


Tracer-hydrological approach: Black box approach

Input Output

Q,C(t) Q,C(t)

bekann bekanntgesucht

System

TBC

known unknown known

observations observations

Frequently used mathematical models:•Piston-flow model•Exponential model•Convection-dispersion model

(and many others!) 26


• Piston-Flow model (PFM) considers only convection

• Exponential model (EM) requires ‘complete mixing’ of the tracer and the water in the system, and it assumes an exponential distribution of the flow path lengths (-> residence times)

• Convection-dispersion model (CDM) considers convection and dispersion of the tracer in the system; analytical solution of the 1D solute transport equation

Brief summary of three frequently used models (details later in this course)

27


1. Investigation of the dominant processes of the system (incl. boundary conditions, tracer, tracer input and output etc.)

2. Selection of the suitable mathematical model(s) to describe the tracer transport in the system

3. Fitting of the modeled breakthrough curve to the observed concentrations

4. Characterization of the system through interpretation of model parameters

General procedure using a black-box approach (artificial and natural tracers)

28

PollutantCi

TracerCi

Transport

Convection

Dilution- Diffusion- Dispersion- Turbulence(mixing)

Retardation- Sorption- Filtration- Chemicalreaction

PollutantCf

TracerCf


Understanding solute/pollution transport through tracer tests

29

What is the power of tracer methods?

• Allow gaining further insights into the flow dynamics of water and solutes (incl.

pollutants) within the water cycle

• Characterization of an investigated hydrological system:

– Flow pathways, hydrological connections, source areas

– Flow velocities, residence times

– Dispersion, diffusion, mixing and sorption

– Etc.

• “Hard data” to parameterize, calibrate and validate hydrological models

End of Introduction (‘take home messages’)

30

What is the power of tracer methods?

• Investigation of surface water:

→Rivers, lakes, man-made reservoirs, vegetation, water vapor, oceans, snow

and ice, etc.

• Investigation of subsurface water:

→Soil water, groundwater (karst, porous aquifers, fissured aquifers), plant

water uptake, etc.

• Surface water – groundwater interactions!

• Contamination and pollution transport

• Vulnerability studies

• ctc.

…. YOU might explore new fields!

31

Introduction

Available Tracers Natural Tracers Artificial Tracers Environmental isotopes Radioactive Inactive Stable Tritium 3H Soluble substances Drifting substances


Oxygen-18 18O Chromium-51 51Cr Na+ Cl- Fluorescent particles Cobalt-58 58Co K+ Cl- Bacteria Carbon-13 13C Bromine-82 82Br Li+ Cl- Viruses Helium-3 3He Iodine-131 131I HBO2 Fungi Sulphur-34 34S Gold-198 198Au




Overview of tracers


Objectives of this lecture

1. Abundance and sorts of hydrochemical tracers and pollution tracers

2. Methodological aspects:

• Application,

• origin of these tracers,

• analysis, and

• Interpretation

Outline of lecture

33

Hydrochemical and pollution tracers

• Hydrochemical tracers (not artificially injected!)

– Contain information because of natural physiographic (geology, soils, land use, climate etc.) and anthropogenic properties

• Pollution tracers are caused by man‘s activities (not natural!)

– Characterize water source areas, flow pathways and residence time of water compartments in different hydrological systems

– Analysis because of physical and chemical properties

Hydrochemical and pollution tracers can be classified as following

34

Hydrochemical tracers

• Temperature

• Electrical conductivity (reciprocal of electrical resistivity)

• pH

• Different anions (e.g., Cl-, SO42-, NO3

-)

• Different cations (e.g., Na+, K+, Ca2+, Mg2+, heavy metals)

• Radon-222, 222Rn

Examples

35


EC and pH as natural tracers – indicating different runoff components

time [h]

0 5 10

run

off [m

3/s

]

0

2

4

6

8

10

12

14

el. c

on

du

ctivity [

uS

/cm

]

40

50

60

70

80

90

100

110

120

pH

6

7

8

9

runoff [m3/s]

el. conductivity [µS/cm]

pH

(Lindenlaub et al., 1997) 36


Water temperature as indicator

1.06.95 1.12.95 1.06.96 1.12.96 1.06.97 1.12.97 1.06.98

Tem

pera

tur

[°C

]

6

8

10

12Quelle: Zängerlehof (Fließsystem-2)

Quelle: Erlenhof (Fließsystem-1)

(Uhlenbrook, 1999)

Spring with shallow groundwater

Spring with deep groundwater

37


Water temperature as indicator: Example distributed temperature sensing DTS

(Suárez et al., 2006) 38

Weierbach catchment (L)

• IR remote sensing via hand-held FLIR camera

Upland zone

Riparian zone

Aquatic zone

Intermittent

connectivity


IR remote sensing via hand-held FLIR camera

Example: IR thermography

39(Pfister, 2012)


- surface temperature mapping

- pixel classification (green : < 8.5°C)

Isolated water patches

Connected pathway

Weierbach

A

B


Surface temperature mapping

Pixel classification (green : < 8.5°C)


40(Pfister, 2012)


Seepage zone A

- Identification of seepage areas, flowpaths and mixing areas

- Identification of surface runoff connectivity


• Identification of seepage areas, flowpaths and mixing areas

• Identification of surface runoff connectivity


41(Pfister, 2012)

Pollution tracers

• Get into the environment through man‘s activities

• Input caused by

– Accidents (point injection in space and time),

– Leaking pipes (point injection but continuous)

– Continuously over larger areas (regional or global) through the atmosphere

• Detectable because of chemical properties

• Decay and decay products are often not known

42

Pollution tracers

• Fluorescence dyes, like uranine, in waste water from private homes (cosmetics, etc.)

-> investigation of groundwater flow

• Bor (B) acid (H3BO3 or HBO2) from washing powder in percolation water from waste dumps

-> investigation of groundwater flow

• Street salt (against freezing in winter)

-> flow paths of surface runoff generated on streets

• Agrochemicals (e.g., atrazine, simazine, terbutylazine)

-> mark flow paths in soil and groundwater

• CFCs: age dating of groundwater

Tracers – Some examples

43

Diatoms as a tracer?

Available Tracers Natural Tracers Artificial Tracers

Environmental isotopes Radioactive Inactive Stable Tritium 3H Soluble substances Drifting substances


Oxygen-18 18O Chromium-51 51Cr Na+ Cl- Fluorescent particles Cobalt-58 58Co K+ Cl- Bacteria Carbon-13 13C Bromine-82 82Br Li+ Cl- Viruses Helium-3 3He Iodine-131 131I HBO2 Fungi Sulphur-34 34S Gold-198 198Au Diatoms




Overview of tracers


• Unicellular, eukaryotic algae• One of the most common algal groups in freshwaters as well as in

marine ecosystems• Characteristic feature : highly differentiated cell wall (called frustule)

that is heavily impregnated with silica (SiO2)

Free living motile

Attached to substrate: stalks or pads Free floating flabellate &

stellate colonies

Chain coloniesFilaments


What is a diatom?

45(Pfister et al., 2009)

• Frustules consist of two valves basic component SiO2 (60%) protection of the cell cytoplasm completely closed ‘box & cover’: 2 large, heavily sculptured units: VALVES upper valve = EPIVALVE (“cover”) lower valve = HYPOVALVE (“box”)

• Enormous diversity in shape & size- Two types of forms:

o Pennates (bilateral symmetry)o Centrics (radial symmetry)

- Dimensions: 5 μm - 2 mm (Average: 10 μm – 100 μm)

• Species-specific cell wall

• Present in aquatic ecosystems and moist terrestrial habitats


What is a diatom?


• Very sensitive to:

- light- moisture conditions- temperature- current velocity- salinity- pH- oxygen- inorganic nutrients (carbon, phosphorous, nitrogen, silica)- organic carbon- organic nitrogen

• Frequently applied at various spatial and temporal scales to geological, archaeological and water quality research


What is a diatom?


- Spatio-temporal variability of storm flow generation

- Diatom species abundance tightly constrained by moisture conditions

- Diatom mobilisation during surface runoff phases

- Identification opportunity of on- / offset of surface runoff

Upland zone

Riparian zone

Aquatic zone

Intermittent

connectivity

Weierbach catchment (L)


Diatoms as new tracer for exploring water source and connectivity?



Major cations and anions

• Anions: HCO3-, Cl-, SO4

2-, PO43-, NO3

-

• Cations: Na+, K+, Ca2+, Mg2+

– These account in most natural waters for more than 98 % of total ion content

– Less frequent are heavy metals, e.g. Fe, Cu, Hg, etc.

– Used for the identification of flow paths and flow components (e.g., hydrograph separation)

– Abundance mainly controlled by geology/soils, but land use (often controlled by man) is also important

– Often do not behave conservatively in hydrological systems

49


• Sodium (Na+)

– Origin: Chemical weathering of, e.g., plagioklas (albit: Na[AlSi3O8]), in precipitation in particular in costal areas, or anthropogenic inputs (waste, sewage etc.)

– Very mobile

• Potassium (K+)

– Origin: Chemical weathering of, e.g., orthoklas (K[AlSi3O8]) und biotite(K(Mg,Fe)3[Si5AlO18]), or anthropogenic (fertilizer)

– Important element for plants (nutrient); uptake is selective

– Strong absorption in clay minerals (potassium fixing)

– High concentrations give a hint to flow pathways in organic rich soil layersor heavily used farm soils

Major cations (1/2)

50


• Magnesium (Mg2+)

– Origin: chemical weathering of, e.g., of dolomite ((Ca,Mg)CO3), biotite(K(Mg,Fe)3[Si5AlO18]) und cordierite (Al3(Mg,Fe)2[Si3AlO8]), or anthropogenic

– Percolation depends on infiltration rates, chemical composition and pH of soil water; generally quite mobile ion

• Calcium (Ca2+)

– Origin: chemical weathering of, e.g., limestone (CaCO3), dolomite ((Ca,Mg)CO3), gypsum or plagioklas (anorthite: Ca(Al2Si2O8), or anthropogenic

– Very mobile ion

Major cations (2/2)

51


Example: Concentration changes during a winter flood in the Brugga basin

Prozent des Anfangswertes

Bruggapegel Oberried

60

80

100

120

140

160

14.12.2000 00:00 15.12.2000 00:00 16.12.2000 00:00 17.12.2000 00:00 18.12.2000 00:00 19.12.2000 00:00

sta

nd

. Io

nen

ko

nzen

trati

on

[%

]

0

1

2

3

4

Du

rch

flu

ss [

m³/

s]

Natrium Magnesium Calcium Q-Brugga

(Didszun, 2002)

Na Mg Ca discharge

52


Example: Ca/Mg-ratio

0

5

10

15

20

25

30

35

40

45

50

0 20 40 60 80 100 120

Mg

[m

g l

-1]

Ca [mg l-1]

Precipitation

Overland flow

Rock-pond

Episodic spring

Springs

Cave

Wadi Flow

Low concentration samples

Mg/Ca = 1:1

(Lange, 2002) 53


• Chloride (Cl-)

– Origin: from sea salt (wind!) into atmosphere and precipitation, chemical weathering, salt or chloride containing minerals (e.g., pyromorphite), or anthropogenic (waste water, street salt etc.)

– Very mobile (small ion radius and negative charge), conservative behavior

• Nitrate (NO3-)

– Origin: atmospheric deposition, biomass, mineralization (micro organisms) processes, and anthropogenic (fertilizer, waste water etc.); geological background often negligible

– Very important nutrient, very mobile, often highly water soluble

• Sulfate (SO42-)

– Origin: atmospheric deposition, pyrite, biomass, mineralization (micro organisms) processes, or anthropogenic

– Mobile, highly water soluble, but often part of organic compounds

– Acidification problem

Major anions

54


• Origin: Silica weathering (hydrolysis)

• In low concentration waters as silica acid : H4SiO4; weak acid, no complete dissociation (pKs: 9-10)

• Concentration depends on:

– Weathering resistance of the mineral (strong to less resistant):quartz > muskovite > orthoklas > plagioklas (albite > anorthite) > biotite > amphibolite > pyroxene > granate > olivine

– Temperature

– pH (H2CO3, organic soil acids, H2SO4, HNO3 etc.)

– Water-rock surfaces (weathering, broken minerals etc.)

– Water-rock contact time (residence time of the water)

• Possible uptake by algae (diatoms) in surface water bodies

• Very useful for identifying water source areas and flow pathways in particular crystalline geology

Dissolved silica (Si) as natural tracer

55

Temperatur [°C]

4 6 8 10 12

Si [m

g/l]

3

4

5

6

7

8Fließsystem-1

Fließsystem-2

lineare Regressionsgleichung

y = 5.43 + 0.22 x (r ²=0.18)

y = 2.93 + 0.26 x (r ²=0.50)

(Uhlenbrook, 1999)

Springs with deep groundwaterSprings with shallow groundwaterLinear regression


Silica and temperature to differentiate different groundwater systems

56


Example

(Hoeg et al., 2000)

P

18O

[‰]

-10.4

0

5

10

15

P [mm/h]

0

1

2

3

1. 2.

3.

4.

6. 7.

8. 9.

5.

Q [m³/s]

-12 -10 -8 -6 -4 -2 P

18

O [‰]

-10.2 -10.0

-9.8

-9.6

-9.4

-9.2

Q

18O

[‰]

55

60

65

70

75

Q el. cond. [S/cm]

4.5

29/06 06/07 13/07 20/07 27/07 03/08 10/08 17/08

3.0

3.5

4.0 Q

SiO2 [mg/l-Si]

P

1 8O

[‰ ]

-10.4

0

5

10

15

P [mm/h]

0

1

2

3

1. 2.

3.

4.

6. 7.

8. 9.

5.

Q [m³/s]

-12 -10 -8 -6 -4 -2 P

18

O [‰]

-10.2

-10.0

-9.8

-9.6

-9.4

-9.2

Q

18O

[‰]

55

60

65

70

75

Q el. cond. [S/cm]

4.5

29/06 06/07 13/07 20/07 27/07 03/08 10/08 17/08

3.0

3.5

4.0 Q

SiO2 [mg/l-Si]

Dissolved silica and electrical conductivity for estimating overland flow during a flood in a catchment in the Black Forest, Germany

57


Hysteresis

58(Hoeg et al., 2000)


• Different analytical methods (titration, photometric, etc.)

• Major ions by using IC (ion chromatography; electrical conductivity detection) or AAS (atomic absorption spectrometry):

– Only 5 ml filtered sample volume is necessary

– Several ions can be analyzed simultaneously

– Costs less than 30 euros per sample

• Dissolved silica, frequently using a photometer

– Only 12.5 ml filtered sample volume is necessary

– Costs less 12 euros per sample

Chemical analysis

59


• Hydrochemical tracers are good for the identification of water origin and flow pathways (indirectly for residence time)

• Hydrochemical tracers are relatively easy to sample and to analyze

• Very useful in particular in combination with environmental isotopes (-> residence times), and further parameters about the hydrological and geological conditions

• Appropriate also at the beginning of a study to develop a conceptual model or to prepare more detailed experiments

• Difficulties and shortcomings:

Space and time variability of all parameters and processes

Good knowledge of general hydrology/hydrogeology is necessary for interpretation

Take home messages

60

Introduction - Runoff generation

–dominating processes during flood

formation1. Introduction

2. Dominating processes during flood formation

1. plot scale

2. hillslope

3. catchment

4. river basin

3. Concluding remarks

Outline of lecture

scale

61

From precipitation to runoff

Introduction

Example: What do we observe between runoff events?

62(Beven, 2001)

Example: What do we observe during runoff events?

63

Introduction

(Beven, 2001)

Introduction

Example: Precipitation amount and intensity

64(McDonnell)

Introduction

• Precipitation, -distribution, - intensity

• Soilmoisture

• Soils and Vegetation

• Groundwater levels (Topography)

• Geology

• etc.

Dominant controls on runoff generation processes

65

Introduction

What are we aiming for? The holy grale of experimental hydrology

66(McDonnell)

(Blöschl & Sivapalan, 1995)

Spatial

scales

Time

scales

River basin

scale

Introduction

Why do we look at different scales separately?

67

~70-80 cm

(Peranginangin, 2002)

Plot scale

Flood Formation at the Plot Scale (~m²)

68

Flood Formation at the Hillslope Scale – Surface runoff

69

Hillslope scale

(COMET )

(Dunne & Leopold, 1978) (W. Bott)

Hillslope scale

Surface runoff, infiltration excess overland flow (Horton)

70

Hortonian overland flow = infiltration excess overlandflow

Horton, 1933: „overlandflow occurs when the rainfall rate is higher than the infiltration rate of the soil. The excess rainfall collects on the soil surface before travelling towards the stream as a thin sheet of water moving across the surface.”

Partial area concept

Betson, 1964: „within a catchment there are only limited areas that contribute overland flow to a storm hydrograph“

71

Hillslope scale

Surface runoff, infiltration excess overland flow (Horton)

(COMET )

Surface runoff, Saturation excess overland flow (Dunne)

72

Hillslope scale

(COMET )

(Dunne & Leopold 1978, after Dunne et al. 1975)

51 % 36,5 % 19,5 %24,5 % 15 %

21 March 23 March 28 March 21 April 25 August

Hillslope scale

(‚variable source area concept‘, Hewlett & Hibbert 1967)

Saturation overland flow & variable source area concept

73

Hillslope scale

Separation of runoff components (new/old water) with natural tracers

preevent water

event water

Event (new) and prevent (old) water!

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60

Time

Str

ea

m D

isc

ha

rge

New Water

Old Water

(from: Mc Donnell, 2003)

74

Sklash & Farvolden (1979)

(Uhlenbrook)

Hillslope scale

Separation of runoff components (new/old water) with natural tracers

1. Qstream = Qold + Qnew

2. Cstream Qstream = Cold Qold + Cnew Qnew

75(Uhlenbrook)

Isotope tracer

• continued on Sabine Keßlers‘ slides – 04 Fluvial transport

76

Hillslope scale

Interaction of surface and sub-surface processes

Variable process dominance for different physiographic conditions

Significance of antecedent moisture

Importance of application of different experimental methods for process identification

Scale dependency of hydraulic conductivity?

Improvement of module of models

Synthesis of many case-studies is necessary

Concluding Remarks: Hillslope Scale

Research gaps – Flood formation

77

Hillslope scale

Dominant flow processes at the hillslope scale (Dunne)

78(Beven 2001)

Gauging station

0 10 km

N

Legend

Surface runoff+ Saturated area, saturation overland flow+ Settlement, hortonian overland flow+ Hard rock outcrop, hortonian overland flow

Boulder field, lateral macropore flow,subsurface stormflow

Upper layer, subsurface storm flow Mean layer, delayed subsurface flow

Valley floor, transition zone+ Dry conditions: interflow transition+ Wet conditions: piston flow-effect

Flat lowland+ Deep porous auifers: surface water/groundwater interactions+ Base flow generation

Periglcial drift cover and accumulation zoneat toe of hillslope,interflow transition and piston flow-effect

Hilly upland and Moraine,base flow generation

Periglacial drift cover,delayed lateral subsurface flow

Gauging station

0 10 km

N

Legend

Surface runoff+ Saturated area, saturation overland flow+ Settlement, hortonian overland flow+ Hard rock outcrop, hortonian overland flow

Boulder field, lateral macropore flow,subsurface stormflow

Upper layer, subsurface storm flow Mean layer, delayed subsurface flow

Valley floor, transition zone+ Dry conditions: interflow transition+ Wet conditions: piston flow-effect

Flat lowland+ Deep porous auifers: surface water/groundwater interactions+ Base flow generation

Periglcial drift cover and accumulation zoneat toe of hillslope,interflow transition and piston flow-effect

Hilly upland and Moraine,base flow generation

Periglacial drift cover,delayed lateral subsurface flow

Catchment scale

Flood formation at the Catchment Scale (~10-1000 km²)

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Catchment scale

Spatio-temporal variability of precipitation (or snow melt)

Dynamic, non-linear superposition of all processes at small scales

Significance of channel processes

Interaction of surface runoff and groundwater

Regionalising of input data and processes

Better understanding of variability and interactions of dominating processes

Integration of new data sources (e.g. remote sensing etc.)

Concluding Remarks: Catchment Scale

Research Gaps – Flood formation processes

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(BfG 2003)

Rainfall distribution, temporal overlay of floodwaves and flood routing

River basin scale

Case study: Flood Formation at the River Rhine and the Influence of the Neckar

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Conclusion

Different physiographic conditions (heterogeneity!)

Large importance of the spatio-temporal distribution of the hydro-meteorological input (snow cover distribution, circulation patterns etc.)

Temporal overlay of flood waves and flood routing

‚up-scaling‘ of process information and data

‚down-scaling‘ from climate models or meso-scale meteorological models

Integrate modeling with modules from hydrology, meteorology, water management etc.

Concluding Remarks: River Basin

Research Gaps – Flood Formation

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Introduction

Lecture partly based on material from

Dipl.-Hydrol. Sebastian Wrede, Univ. Trier Prof. Stefan Uhlenbrook (UNESCO-IHE, The Netherlands) Prof. Chris Leibundgut, Univ. of Freiburg, Germany (i.e. general, artificial

tracers) Prof. Jeff McDonnell, Oregon State Univ., Corvallis, USA (i.e. isotope

tracers) Dr. Jens Lange (i.e. general, artificial tracers, case studies)

Acknowledgements for the material used in this course

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01 Fluvial Systems 2014 Runoff Tracer

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