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choppedspleenMécanique

21 févr. 2014 (il y a 3 années et 1 mois)

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B.T. Nolte, R.S.E.W. Leuven, P.H. Nienhuis


Department of Environmental Studies, University of Nj
j
megen, The Netherlands;

Participant of the Netherlands Centre for River Studies.

Linking sedimentation and ecology in riverine

floodplains: Influences of climate change and physical

reconstruction measures

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Introduction

Floodplain

soils

along

the

Rhine

and

Meuse

in

the

Netherlands

play

an

important

role

as

sinks

of

suspended

sediment

and

pollutants

and

have

a

key

role

in

ecological

transformation

processes

along

the

river

continuum
.

These

soils

show

a

large

spatial

variability

in

pollution
.

Climate

change

and

physical

reconstruction

measures

for

increasing

the

discharge

capacity

are

expected

to

cause

considerable

changes

in

sedimentation

processes
.

Therefore

the

Universities

of

Utrecht

and

Nijmegen

initiated

a

project

that

aims

at

(
1
)

quantification

of

the

interactions

between

sediment

transport

and

ecosystem

functioning

of

floodplains

and

(
2
)

assessment

of

human

interference

and

climate

change

on

fine

sediment

transport

and

ecological

transformations
.

This

project

is

part

of

the

NWO
-
LOICZ

programme


Bio
-
geomorphological

interactions

within

floodplains

and

their

role

in

sediment

transport

and

ecological

transformation

processes

in

the

lower

Rhine

delta

.

The

sub
-
project

of

the

University

of

Nijmegen

focuses

on

the

ecological

functioning

and

transformation

processes

in

the

floodplain
.

This

poster

presents

a

procedure

for

a

GIS
-
based

ecological

risk

assessment

(ERA)

of

changes

in

sedimentation

processes

and

sediment

pollution
.

Future

research

Future

research

will

be

focused

on

refinement

of

several

modules

of

the

GIS
-
based

ERA

(risk

estimation

on

population

level,

bio
-
availability,

foodweb

modelling)
.

Subsequently,

it

will

be

applied

to

various

river

floodplains

(including

uncertainty

analysis)
.

Finally,

the

impacts

of

changes

of

sedimentation

processes

on

ecological

transformations

will

be

estimated
.


The

procedure

consists

of

three

major

steps
:








Step

1

Selection

of

valuable

data

from

the

input

database

for

r i s k

a s s e s s m e n t
.








S t e p 3

A p p l i c a t i o n

of

output

data

in

an

exposure

model

that

takes

into

account

the

effects

of

bio
-
accumulation

of

pollution
.

Using

GIS,

site

specific

risk

maps

for

the

focal

species

can

be

produced
.








Step 2

The

development

of

GIS
-
maps

(habitat

and

fouraging

area

of

focal

species

and

various

layers

of

soill

pollution)
.


Conceptual framework for GIS
-
based ERA

For

an

accurate

risk

estimation

heteroge
ne
ity

of

soil

pollution

has

to

be

included

in

the

risk

assessment
.

The

procedure

incorporates

spatial

components

of

exposure

into

the

ERA

by

linking

GIS
-
data

with

external

risk

models

that

estimate

the

exposure

of

riverine

foodwebs

(including

focal

species

of

river

management)
.

The

procedure

will

be

modelled

in

A
rc
I
nfo

7
.
1

(part

of

the

entire

ArcGis

network),

which

also

allows

the

connection

with

other

external

models

(such

as

exposure,

bioavailability,

and

foodweb

models)
.