Les transferts fluviaux: échelles de temps et d’espace. Les transferts fluviaux: échelles de temps et d’espace.

SPACE AND TIME SCALES IN RIVERINE TRANSFERS : M. Meybeck Orléans 22.03.2005

ATMOSPHERE

ANTHROPOSPHERE

TERRESTRIAL VEGETATION, SOIL

GROUNDWATERS

RESERVOIRS LAKES

CONTINENTAL SEDIMENTS

COASTALZONE

OPEN

OCEAN

WETLANDS

RIVERS

COASTALSEDIMENT

OCEANSEDI-MENT

8 9

10

13 14

21

16 SILTING15

UPLIFT

11

CH4 CO2 WATER

17

WATER CH4 CO2

5

EROSION

WEATHERING

43, 5

CH4 N2OWATER DUST

CH4 CO2 N2O6

1 2

CO2

ENERGY

WATER

SEDIMENTS

CARBON

NUTRIENTS

2 0

18

7 19

7

22 22

SURFACE LITHOSPHERE

12

22

11

1 = N fixation, 2 = water consumption, 3 = fertilisation, 4 = food and fiber consumption, 5 = waste release, 6 = atmospheric pollutants fallout, 7 = water abstraction and diversion, 8 = land use (deforestation, cropping, urbanisation), 9 = draining, 10 = salinization, contamination, depletion, 11 = irrigation, 12 = diversion, 13 = evaporation, regulation, eutrophication, 14 = eutrophication, 15 = damming, water storage, diversion, 16 = silting, 17 = mining, 18 = industrial transformation, 19 = enhanced soil erosion, 20 = xenobiotics fluxes, 21 = changes of inputs to coastal zone, 22 = changes in Green House Gases emission.

Spatial organisation of terrestrial aquatic systems.Spatial organisation of terrestrial aquatic systems.

Spatial organisation of terrestrial aquatic systems.Spatial organisation of terrestrial aquatic systems.

RIVER BED INCISION

SLOPES LAKESALLUVIAL PLAINS

DELTAIC SEDIMENT

COASTAL SEDIMENT

NATURAL SOIL EROSION

RIVER BED

ATMOSPHERIC FALLOUT

SINKS & EXCHANGES

UPPER COURSE MIDDLE/LOWER COURSE ESTUARY/DELTA COAST

1

2

3 4 5 6 7 8 9 10 11 12

13

16

S1

S2 S3

S4 S5 S6 S7

U

NATURAL ORIGINS AND PATHWAYS OF RIVER PARTICULATESNATURAL ORIGINS AND PATHWAYS OF RIVER PARTICULATES

14

15 a 15 b

• In natural conditions, sediment transfert is a succession of sources and sinks : delivery ratio is usually 10 to 20 %

• Sediment survey may capture different pictures of this transfer

ATMOSPHERE

SOIL

VEG

GW

AGRIC. HUMANS

SLP

COAST

FILTERS

WL

SED

LK

SED

FLP

SED

EST

SED

F1 F2 F3 F4 F5

F0

SED

Sédim. deposition

Biogeoch. cycling

FILTERS POSITIONS

Gaz escape; evap.

SOIL

ARHEIC

In addition to the soil/plant filter (F0), different types of filters control the pathways and transfers of river borne material: slopes and piedmonts (F1), headwaters wetlands (F2), lakes (F3), inundated floodplain (F4) and estuaries (F5). Human impacts are very limited.

RHEIC

Fev

F0

F1 F2

F4

F5COAST

ARHEIC

F3

Fev

SCHEMATIC POSITION OF RIVER MATERIAL FILTERS WITHIN SCHEMATIC POSITION OF RIVER MATERIAL FILTERS WITHIN PRISTINE RIVER SYSTEMS.PRISTINE RIVER SYSTEMS.

FLUVIAL FILTERINGFLUVIAL FILTERING

F

100 km

V S

TU

Q1

R

Q2

P

J2

G2

G1

E J1

A

B CE

D

J

K

M

N

O

G1

FH

L

UPPER SEINE

MARNE

OISE

SEINE

SPATIAL DISTRIBUTION OF PARIS IMPACTS ON THE SEINE RIVER

• Paris megacity (10 M people), 2 500 km2 has been the major driving force of the Seine basin for the last 1000 years

• Flow regulation, channelization, sand extraction, waste water release are among the major pressures

SEINE BASIN ANALYSISSEINE BASIN ANALYSIS

Figure 6. Schematic ranking of median water quality indicators in the Seine River by stream orders from headwaters to river mouth (500 km). BGR = natural background (forest streams orders 1 to 3); AGR = stream orders 1 and 2 impacted by agriculture. Note log-scales. Arrow indicates the release of Paris treated sewers. Upper: Natural products with marked impacts of point sources and/or urbanization: annual median concentration in water and annual mean contents in particulates, normalized to natural background (CN) generally increasing with population density. Middle: Natural products with marked impacts of diffuse sources (atmospheric fallout for Cl-; agriculture for NO3-, K+ , and particulate phosphorus=PP) and of eutrophication occuring on orders 4 to 8 (algal POC production and dissolved silica uptake); increase of minimum TSS due to eutrophication, navigation, and sewer inputs. Annual means of median normalized to natural background (C). Lower: Xenobiotics. Mean PCBÕs and maximum spring atrazine normalized to river mouth mean value (C). Note log-scales. Arrow indicates the release of Paris treated sewers.

N

OUT

50

20

10

5

2

1

10 20 50 100 150 250 250BGR AGRPOP.

DENSITYp km

-2

PARIS MEGACITY

Hg, Ag

NH4

+

Pb, Zn

Na+

DOC, SO4

--

Mg, Ca,

HCO, Co

++ ++

-3

POINT SOURCES IMPACT

STREAMORDER

DIFFUSE SOURCES IMPACT 50

20

10

5

2

1

0.5

BGR AGR 3 4 5 6 7 8

ALGAL POC Cd

NO3

-

ClK, PP

+

TSSMIN

SiO2

XENOBIOTICS

STREAMORDER

MAX. ATRAZINE

PCBs

BGR AGR 3 4 5 6 7 8

0.1

1.0

10.0

C/CN

C/COUT

C/CN

Figure 6. Schematic ranking of median water quality indicators in the Seine River by stream orders from headwaters to river mouth (500 km). BGR = natural background (forest streams orders 1 to 3); AGR = stream orders 1 and 2 impacted by agriculture. Note log-scales. Arrow indicates the release of Paris treated sewers. Upper: Natural products with marked impacts of point sources and/or urbanization: annual median concentration in water and annual mean contents in particulates, normalized to natural background (CN) generally increasing with population density. Middle: Natural products with marked impacts of diffuse sources (atmospheric fallout for Cl-; agriculture for NO3-, K+ , and particulate phosphorus=PP) and of eutrophication occuring on orders 4 to 8 (algal POC production and dissolved silica uptake); increase of minimum TSS due to eutrophication, navigation, and sewer inputs. Annual means of median normalized to natural background (C). Lower: Xenobiotics. Mean PCBÕs and maximum spring atrazine normalized to river mouth mean value (C). Note log-scales. Arrow indicates the release of Paris treated sewers.

N

OUT

50

20

10

5

2

1

10 20 50 100 150 250 250BGR AGRPOP.

DENSITYp km

-2

PARIS MEGACITY

Hg, Ag

NH4

+

Pb, Zn

Na+

DOC, SO4

--

Mg, Ca,

HCO, Co

++ ++

-3

POINT SOURCES IMPACT

STREAMORDER

DIFFUSE SOURCES IMPACT 50

20

10

5

2

1

0.5

BGR AGR 3 4 5 6 7 8

ALGAL POC Cd

NO3

-

ClK, PP

+

TSSMIN

SiO2

XENOBIOTICS

STREAMORDER

MAX. ATRAZINE

PCBs

BGR AGR 3 4 5 6 7 8

0.1

1.0

10.0

C/CN

C/COUT

C/CN

STREAM ORDER PROFILES OF AVERAGE WATER QUALITY

SEINE BASIN ANALYSISSEINE BASIN ANALYSIS

C/Cout

C/CN

Paris

Figure 6. Schematic ranking of median water quality indicators in the Seine River by stream orders from headwaters to river mouth (500 km). BGR = natural background (forest streams orders 1 to 3); AGR = stream orders 1 and 2 impacted by agriculture. Note log-scales. Arrow indicates the release of Paris treated sewers. Upper: Natural products with marked impacts of point sources and/or urbanization: annual median concentration in water and annual mean contents in particulates, normalized to natural background (CN) generally increasing with population density. Middle: Natural products with marked impacts of diffuse sources (atmospheric fallout for Cl-; agriculture for NO3-, K+ , and particulate phosphorus=PP) and of eutrophication occuring on orders 4 to 8 (algal POC production and dissolved silica uptake); increase of minimum TSS due to eutrophication, navigation, and sewer inputs. Annual means of median normalized to natural background (C). Lower: Xenobiotics. Mean PCBÕs and maximum spring atrazine normalized to river mouth mean value (C). Note log-scales. Arrow indicates the release of Paris treated sewers.

N

OUT

50

20

10

5

2

1

10 20 50 100 150 250 250BGR AGRPOP.

DENSITYp km

-2

PARIS MEGACITY

Hg, Ag

NH4

+

Pb, Zn

Na+

DOC, SO4

--

Mg, Ca,

HCO, Co

++ ++

-3

POINT SOURCES IMPACT

STREAMORDER

DIFFUSE SOURCES IMPACT 50

20

10

5

2

1

0.5

BGR AGR 3 4 5 6 7 8

ALGAL POC Cd

NO3

-

ClK, PP

+

TSSMIN

SiO2

XENOBIOTICS

STREAMORDER

MAX. ATRAZINE

PCBs

BGR AGR 3 4 5 6 7 8

0.1

1.0

10.0

C/CN

C/COUT

C/CN

C/CN

ParisBGR : Orders 1 to 2 forested

AGR : Orders 1 to 3 rural (<20 p/km2)

• Space distribution of water quality indicator is

highly dependant on stream order/ population density/types of human

pressure

• Normalized indicators permit space analysis

NEGLIGIBLE

IMPACT SEVERITY

SEVERE

MODERATE

1 A2

76

5

4

31 B

EXTERNAL

ENGLISH CHANNEL

SEINE ESTUARY

DISTAL PROXIMAL LOCAL PROXIMAL DISTAL EXTERNAL

PARIS MEGACITY

IMPACT PROFILES OF PARIS MEGACITY ON THE SEINE RIVER

1.A, 1.B Organic Pollution2. Combined Sewer Overflow3. Estuarine nitrification4. Metal Contamination

5. Habitat degradation6. Atmopsheric pollution7. Timber rafting (1600-1920)

0 70 200 30050400 200 km

SEINE BASIN ANALYSISSEINE BASIN ANALYSIS

Regulated water flux

Contaminated water

GROUNDWATER

F1

LK FLPL

F4

EST

F5

WL

F3

CROPSOIL

INDURB

AGRI

MININGENERGY

TRANSPNET

STORAGE

Fo

ATMOSPHERELRAP

J

COAST

B C D E

SLP

F1 F2

A

IH

VEGETATION

G

F6 F7Artificial filters

Artificial river network

Fluxes of contaminants

Socio economic systems

Sub pristine environment

Impacted/regulated environment

Natural filters

F0 / F5Pristine water

Material, information and financial fluxes within anthroposhere

Agrochemicals

Transition environment

STP WD

F6

RESERV

Crop

Sediment

F5Coast

F3F2

F0

F4

F1

F6

F7

D

H

EH

C

F1

LRAP

FILTERS POSITIONSJ

IRRIGATED FIELDF7

CROPA

Fev

Evaporation

FLUVIAL SYSTEM FUNCTIONING IN THE ANTHROPOCENE FLUVIAL SYSTEM FUNCTIONING IN THE ANTHROPOCENE POLLUTED/REGULATED FLUVIAL SYSTEMPOLLUTED/REGULATED FLUVIAL SYSTEM

FLUVIAL FILTERINGFLUVIAL FILTERING

EXAMPLES OF RESERVOIRS IMPACTS ON LAND-OCEAN FLUXES

In the Mediterranean watershed the sediment load has been reduced from 620 M t/y to 180 M t/y.

Globally the sediment storage in large dams is 5 billions t/y (circa 25% of present flux) ; could be double if small

reservoirs are considered.

In dry regions impoundments are associated with water losses through evapotranspiration for irrigation

(2,55 M km2 globally) and marked reduction of river flows to oceans, towards "neoarheism" as :

Asia : Amu Darya, Syr Daria, Yellow, IndusNorth America : Colorado, Rio Grande

Africa : Nile, OrangeAustralasia : Murray

Time scales of responses of aquatic systems to changes

RIVER EUTROPHICATION : DAILY pH CYCLES IN THE RIVER EUTROPHICATION : DAILY pH CYCLES IN THE LOIRE RIVER(AT DAMPIERRE)LOIRE RIVER(AT DAMPIERRE)

• During spring and summer algal blooms (chloro A > 100 µg/L) the daily pH cycles may reach 1.2 pH units

• Such events can only be noted during stable low flows : they are destroyed by floods

PA68

F. Moatar (1999, Univ. Tours)

EUTROPHICATIONEUTROPHICATION

∆pH

Dis

char

ge

NITRATE TRENDS IN WORLD RIVERSNITRATE TRENDS IN WORLD RIVERS

From 1960 to 1990 nitrate has increased in most

large riversMaximum rates are observed in smaller

catchments exposed to intensive fertilizer use

SD11

Seine

Rhine

Danube

Mississippi

Thames

EUTROPHICATIONEUTROPHICATION

A SUCCESS STORY : NUTRIENTS CONTROL IN THE RHINE R.A SUCCESS STORY : NUTRIENTS CONTROL IN THE RHINE R.

• The major effort of sewage collection was between 1960 and 1975 : it resulted in particulate P abatment and NH4

+ decrease

• P-PO43- control then decrease was only achieved after the 1985 ban

of P detergents and the dephosphatation in most treatment plants

Van Dijk & Marteijn, 1993

EUTROPHICATIONEUTROPHICATION

mg P /L

mg P /L

SCHEMATIC TRENDS OF SEDIMENT SCHEMATIC TRENDS OF SEDIMENT CONTAMINATION IN ESTUARINE CORESCONTAMINATION IN ESTUARINE CORES

• Heavy metals (A) have peaked in the 1960 ’s (USA) to the 1980 ’s (some W. Europe rivers), their trends are barely documented on other continents• Carcinogenic polyaromatic carbons may still increase in some regions

• Polychlorinated biphenyls do not exist in nature (xenobiotics) : they trace the modern human pressure

• Both PAHs and PCBs are inadequately surveyed in rivers

TE3

CONTAMINATIONCONTAMINATION

OLDEST HUMAN IMPACT (Pb, Cu, As…) RECORDED IN RIVER OLDEST HUMAN IMPACT (Pb, Cu, As…) RECORDED IN RIVER SEDIMENTS : RIO TINTO PREHISTORIC MINES, 2500 BC (SPAIN)SEDIMENTS : RIO TINTO PREHISTORIC MINES, 2500 BC (SPAIN)

Leblanc et al, 1999 (Montpellier University)

PF33

• Rio Tinto gold mines were already active more than 4500 y ago

• Resulting heavy metal contamination has been enormous :

Hg100, Pb1500, As50• Mining is still going on in this region where the geochemical

background has been modified since millenia (inheritated pollution)

CONTAMINATION HERITAGECONTAMINATION HERITAGE

6 000 BP

3 000 BP

2 550 BP

1930 BP

1 10 10000,01

SUCCESSFULL REMEDIATION OF WATER QUALITY ISSUESUCCESSFULL REMEDIATION OF WATER QUALITY ISSUE

• CN natural concentration, CR recommended concentration, CL limit concentration

• Solving water quality issues takes at least 20 y and more (e.g. Great Lakes, Leman L., Rhine R.)

• Social inertia are cumulated with environmental inertia (e.g. water residence time, particulates transfer)

• Many Human impacts and/or water-related structures can be regarded as permanent (e.g. mine tailings, large dams, sewage networks, i.e. lasting 100 to 1000 y)

MAN AND RIVER RELATIONSMAN AND RIVER RELATIONS

TYPOLOGIES OF RIVER BASIN MANAGEMENT SRATEGIES FOR WATER QUALITY ILLUSTRATED BY TRENDS IN WATER

QUALITYMANAGED ISSUES

F

E

C

D

B2

B1

HCN3

CL

CR

CN1

T0 T2TIME

NEGLIGIBLE IMPACT

MODERATE IMPACT

SEVERE IMPACT

PRISTINE

CN1, CN2, CN3, natural, (CR) recommended and (CL) limit concentrations. T0 = start of environmental pressures (), T2 = environmental impact detection (), T4 = start of environmental measures (), unplanned decrease of environmental pressures (). A1 and A2 : unecessary management, B1 : precaution management, B2 : delayed precaution management, C : maximum impact management, D : total ban, E : delayed pollution regulation, F : laissez-faire, G : unplanned improvement, H : natural pressure remediation, I : unperceived issue, J1 and J2 : natural pressure endurance and natural pressure suffering.

TYPOLOGIES OF RIVER BASIN MANAGEMENT SRATEGIES FOR WATER QUALITY ILLUSTRATED BY TRENDS IN WATER

QUALITYUNMANAGED ISSUES

CN1, CN2, CN3, natural, (CR) recommended and (CL) limit concentrations. T0 = start of environmental pressures (), T2 = environmental impact detection (), T4 = start of environmental measures (), unplanned decrease of environmental pressures (). A1 and A2 : unecessary management, B1 : precaution management, B2 : delayed precaution management, C : maximum impact management, D : total ban, E : delayed pollution regulation, F : laissez-faire, G : unplanned improvement, H : natural pressure remediation, I : unperceived issue, J1 and J2 : natural pressure endurance and natural pressure suffering.

I

G

J1

J2

A2

A1

CN3

CL

CN2

CR

CN1

T0 T2TIME

NEGLIGIBLE IMPACT

MODERATE IMPACT

SEVERE IMPACT

PRISTINE

10 to 100 y

Continental Aquatic Systems shared by the Anthroposphere and the Earth System at the Anthropocene 

EARTH SYSTEM

COMPONENTS

GLOBAL CHANGE DRIVERS

HUMAN DRIVERS

RESOURCESSERVICES

RIVER SYNDROMES• chemical alteration

• salinisation• acidification

• eutrophication• flow regulation• fragmentation

• silting• neoarheism

EARTH SYSTEM

RESPONSE

EARTH SYSTEM

CHANGES

ANTHROPOSPHERE EARTH SYSTEM

SHORT TERM REACTION

LONG TERM REACTION

SOCIETAL RESPONSES

SOCIAL AND ECONOMIC

IMPACTS

CONTINENTAL AQUATIC SYSTEMS

CONTROL

FUNCTIONS

PRESSURES

RISKS USES

CHANGES

HUMAN IMPACTSHUMAN IMPACTS

Anthropogenic climate variability

ENVIR. REGUL.

ATM. POLL. CONTROL

RENATUR. / RESTOR.SEWAGE COLL. /TREAT.

REGULATION/RESTORATIONRESPONSES

HUMAN PRESSURES AGROCHEMICALSATM. POLLUTIONMINING IMPACTSURBAN POP. IMPACTS

LAND USERIVER ENGINEERING

TIME0 18001000 1900 1950 2000

ART. GW RECHARGEECOL. FARMING

< 0,1% global area affected

0,1 to 1%Natural climate variability

1 to 10 %

10 to 50 % > 50 %

Figure M6 : Working hypotheses on the occurrence of some major pressures on terrestrialaquatic systems at the global scale and related environmental remediation responses (notethe time acceleration)(adapted from Meybeck, 2001)

CLIMATE VARIABILITY

Anthropogenic climate variability

ENVIR. REGUL.

ATM. POLL. CONTROL

RENATUR. / RESTOR.SEWAGE COLL. /TREAT.

REGULATION/RESTORATIONRESPONSES

HUMAN PRESSURES AGROCHEMICALSATM. POLLUTIONMINING IMPACTSURBAN POP. IMPACTS

LAND USERIVER ENGINEERING

TIME0 18001000 1900 1950 2000

ART. GW RECHARGEECOL. FARMING

< 0,1% global area affected

0,1 to 1%Natural climate variability

1 to 10 %

10 to 50 % > 50 %

Figure M6 : Working hypotheses on the occurrence of some major pressures on terrestrialaquatic systems at the global scale and related environmental remediation responses (notethe time acceleration)(adapted from Meybeck, 2001)

CLIMATE VARIABILITY

Anthropogenic climate variability

ENVIR. REGUL.

ATM. POLL. CONTROL

RENATUR. / RESTOR.SEWAGE COLL. /TREAT.

REGULATION/RESTORATIONRESPONSES

HUMAN PRESSURES AGROCHEMICALSATM. POLLUTIONMINING IMPACTSURBAN POP. IMPACTS

LAND USERIVER ENGINEERING

TIME0 18001000 1900 1950 2000

ART. GW RECHARGEECOL. FARMING

< 0,1% global area affected

0,1 to 1%Natural climate variability

1 to 10 %

10 to 50 % > 50 %

Figure M6 : Working hypotheses on the occurrence of some major pressures on terrestrialaquatic systems at the global scale and related environmental remediation responses (notethe time acceleration)(adapted from Meybeck, 2001)

CLIMATE VARIABILITY

ENVIR. REGUL.ATM. POLL. CONTROLRENATUR. / RESTOR.SEWAGE COLL. /TREAT.

REGULATION/RESTORATIONRESPONSES

AGROCHEMICALS

MINING IMPACTSURBAN POP. IMPACTS

LAND USE

ART. GW RECHARGEECOL. FARMING

Figure M6 : Working hypotheses on the occurrence of some major pressures on terrestrial aquatic systems at the globalscale and related environmental remediation responses (note the time acceleration)(adapted from Meybeck, 2001)

0,1 to 1%

10 to 50 % ANTHROPOGENICCLIMATE VARIABILITY

< 0,1% GLOBAL AREA AFFECTED

NATURAL CLIMATE VARIABILITY1 to 10 %

> 50 %

HUMAN PRESSURESATM. POLLUTION

RIVER ENGINEERING

TIME0 18001000 1900 1950 2000

CLIMATE VARIABILITY

Human responses to environmental impacts are usually delayed

Meybeck, 2001

SOUTH AMERICA

CL

CR

CN

SEVERE IMPACT

MODERATE IMPACT

NEGLIGIBLE IMPACT

PRISTINE

- 2000 0 1000 1492 1900 1950 1970 2000

anthropocene

A2

B

C

D

E

?

?

A1

WORKING HYPOTHESES ON THE EVOLUTION OF WATER QUALITY ISSUES IN THE NEW WORLD (AMERICAS,

AFRICAS, SOUTH ASIA, AUSTRALASIA) FOR SOME KEY ISSUES

A : metal contamination. B : organic and faecal contamination. C : nitrate pollution. D : organic micropollutants (xenobiotic). E : radionucleids. Accelerated time scale.

WORKING HYPOTHESES ON THE EVOLUTION OF WATER QUALITY ISSUES IN THE OLD WORLD (EUROPE,

MEDITERRANEAN BASIN, MIDDLE EAST, EAST ASIA) FOR SOME KEY ISSUES

OLD WORLD

CL

CR

CN

PRISTINE

SEVERE IMPACT

MODERATE IMPACT

NEGLIGIBLE IMPACT

- 2000 0 1000 1492 1900 1950 1970 2000

A

B

C

D

E

LOCAL IMPACTS REGIONAL GLOBAL anthropocene

A : metal contamination. B : organic and faecal contamination. C : nitrate pollution. D : organic micropollutants (xenobiotic). E : radionucleids. Accelerated time scale.

Trajectories of riverine fluxes of contaminants and nutrients Trajectories of riverine fluxes of contaminants and nutrients during the Holocene and Anthropocene (accelerated time during the Holocene and Anthropocene (accelerated time

scale)scale)

FLUVIAL FILTERINGFLUVIAL FILTERING

HOLOCENEANTHROPOCENE

IA

IB

IC

10 000 0 1000 1700 1950 2000 2100

IIA,B

Holocene range

Paleo and Historical records

Surveys Scenarios

Flux

AD t

A

B

IIC

Emissions = retentions

Emissions > Retentions

Retentions > Emissions