Joint project Spree

Matter transformation in the Spreewald wetland region

Study siteStudy site

   channel network with high density

high groundwater table, 30% fens

water consumptive area in summer time

groundwater-table control (13 cascades)

different flooding regimes during winter and summer seasons with partly flooding

low flow velocities in channels

vm = 0,01 m/s for MQ in the Upper Spreewald

vm = 0,1 m/s for MQ in the Lower Spreewald

 

Water quality processesWater quality processes

Q, c input (e.g. Spree, Malxe)

t, v Hydraulic structures

c

c

pore water concentrations

water column

± Q, c

c

?

area water exchange, loads

matter concentrations of sediment

Conceptual modelConceptual model

Reduction o

f the n

etwork 4630000 4632500 4635000 4637500 4640000 4642500 4645000 4647500

5745000

5747500

5750000

5752500

5755000

Modelled structureModelled structure

Scheme

Complex model DUFLOW

Data acquisition, monitoring networks

Hydrology, Hydraulics Water quality

Discharges (1991-2000, monthly mean)

Surface water quality (1991-2000, monthly, appointed date)

Channel network, profiles Ground water quality (near to surface)

Water levels at weirs (1991-2000, monthly mean)

Rate data (reaction kinetics)

Ground water levels Sediment chemistry

Distribution of substrates

Pore water profiles

Chemical composition of substrates

Simulation Simulation accuracyaccuracy of transfer functions of transfer functions

o-PO4-P ganzjährig

0

0,04

0,08

0,12

0 0,02 0,04 0,06 0,08 0,1 0,12 0,14

o-PO4-P gemessen (mg/l)

o-P

O4-P

ber

ech

net

(mg

/l)

K (Transferfunktion) 1:1 +25% -25%

NO3-N Sommerhalbjahr

0

1

2

3

4

0 1 2 3 4

NO3-N gemessen (mg/l)

NO

3-N

be

rec

hn

et

(mg

/l)

K (Transferfunktion) 1:1 +25% -25%

NO3-N Winterhalbjahr

0

1

2

3

4

0 1 2 3 4

NO3-N gemessen (mg/l)

NO

3-N

ber

ech

net

(mg

/l)

K (Transferfunktion) 1:1 +25% -25%

Chlorid ganzjährig

0

20

40

60

0 10 20 30 40 50 60

Chlorid gemessen (mg/l)

Ch

lori

d b

erec

hn

et

(mg

/l)

K (Transferfunktion) +25% 1:1 -25%

Sulfat-Sommerhalbjahr

0

100

200

300

400

500

600

0 100 200 300 400 500

Sulfat gemessen

Sul

fat b

erec

hnet

Sulfat-Winterhalbjahr

0

100

200

300

400

0 100 200 300 400

Sulfat gemessen

Su

lfa

t b

ere

ch

ne

t

Sink and source function for sulphateSink and source function for sulphate

Hydraulic calculations for different discharge scenarios:

Summer- half year (SH) NW, MW, MHW, Winter- half year (WH) MW, HW

Area loads: simulated by „ArcGRM Spreewald“ in dependence on time (month) and input discharge

Algorithm for sulphate:

4600000 4620000 4640000 4660000 4680000

5730000

5740000

5750000

5760000

5770000

Sulfat

1000.00

775.00

550.00

325.00

100.00

4SOW4SO4SO CTk

x

Cu

CSpree = 1000 mg/l

CLeibsch = 381 mg/l

010203040506070

SH_NW SH_MW SH_MHW WH_MW WH_HW

ZuflußszenarienS

ulf

atf

rac

ht

in k

g/s

0

200

400

600

800

1000

Su

lfa

tko

nze

ntr

ati

on

in

mg

/l

Input Output C out Spree C in Spree

SH_NW SH_MW SH_MHW WH_MW WH_HW

Portion on sulphate load reduction by running water system (sink)

% of input

21 18 12 21 10

Load reduction by water consumption and flooding (infiltration, sink)

% of input

15 2 2 0 0

Load addition by ground water (exfiltration, source)

% of output

0 0,1 3 4,5 0

Sulphate reduction

by the

Spreewald wetland region

• Water quality modelling of the Spreewald wetland region at catchment scale needs model reductions

• Reduced model has to consider the main quality processes

• Special effect of wetlands is the load exchange with adjacent areas (in both directions)

• Governmental monitoring systems are not sufficient for data supply

SummarySummary

Confluence of Große Fließ and Mittelkanal

Thank you