Modelling N and P retention in wetlands-
This presentation is the property of its rightful owner.
Sponsored Links
1 / 22

Master thesis by Jan Petersson Linnaeus University Kalmar PowerPoint PPT Presentation


  • 52 Views
  • Uploaded on
  • Presentation posted in: General

Modelling N and P retention in wetlands- the effect of planned wetlands within the catchment of the river Tullstorpsån. Master thesis by Jan Petersson Linnaeus University Kalmar River Basin District Authority for the Southern Baltic Sea Sweden. 2011-02-03 WAB-meeting in Sopot, Poland.

Download Presentation

Master thesis by Jan Petersson Linnaeus University Kalmar

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Master thesis by jan petersson linnaeus university kalmar

Modelling N and P retention in wetlands- the effect of planned wetlands within the catchment of the river Tullstorpsån

Master thesis by Jan Petersson

Linnaeus University Kalmar

River Basin District Authority for the Southern Baltic Sea

Sweden

2011-02-03 WAB-meeting in Sopot, Poland


Master thesis by jan petersson linnaeus university kalmar

Catchment of Tullstorpsån


Master thesis by jan petersson linnaeus university kalmar

Background

  • The Swedish River Basin District Authorities

  • Responsible for the coordination and implementation of the Water Framework Directive in Sweden

  • Good status for all waters until 2015 (surface waters as well as ground water)

  • 5 districts, natural borders – marine basins

Bothnian bay

water district

Bothnian sea

water district

North baltic water district

Skagerrak and

Kattegat

water district

South Baltic

water district


Master thesis by jan petersson linnaeus university kalmar

Surface waters with eutrophication problems

Cost effective measures

Reduction versus investment

All costal areas

1/3 of all inland waters

$

Kg

Background

Bothnian bay

water district

Bothnian sea

water district

North baltic water district

Skagerrak and

Kattegat

water district

South Baltic

water district


Master thesis by jan petersson linnaeus university kalmar

Modeling Project

  • Hydrologi and Water Quality models

  • 5 pilot areas

  • Describes tot-N and tot-P losses from land to the ocean

  • Effectiveness of measures

Söderköpingsån

Svartån

Öland

Main Goal

Provide basic information for the realization of more detailed programs of measures to reduce eutrophication in rivers and lakes.

Lyckebyån

Coastal area Skåne


Master thesis by jan petersson linnaeus university kalmar

Meteorological data

Precipitation

Temperature

Evaporation

Waterflow

N- and P sources

Diffuse- & Point sources

N & P conc.

N P

N P

N P

Calibration

N P

N P

Transport and retention

N P

MIKE BASIN

Hydrology,

NAM

Load Calculator,

LC

Water Quality,

WQ


Master thesis by jan petersson linnaeus university kalmar

Mathematical modells for N and P retention in wetlands

(Wittgren et al. 2001; Tonderski et al. 2005)

  • Differential equations

  • Calibrated against real wetlands in the southern part of Sweden.

  • Retention dependent on:

    • Water flow

    • Water temperature

    • Incoming N- & P conc.

    • Wetland area

    • Wetland volume

Background

Wetlands as a measure to reduce the N and P load

  • Limited knowledge of the effectiveness

  • Literature review (2004)

  • N: ~30 – 3000 kg/ha/year

  • P: ~5 – 700 kg/ha/year

  • Positive influence on the retention

  • High nutrient load per unit area

  • High concentration + moderate water flow


Master thesis by jan petersson linnaeus university kalmar

Background

MIKE BASIN

Mathematical modells for N and P retention in wetlands

(Wittgren et al. 2001; Tonderski et al. 2005)

River Basin District Authority´s

Hydrologi and water qualitymodel

Costal area of Skåne

Effect on N and P load

from the catchment of

Tullstorpsån


Master thesis by jan petersson linnaeus university kalmar

Background

Catchment of the river Tullstorpsån and planned wetland locations

  • 49 wetlands (area: 0,2 – 5 ha)

  • Part of a larger initiative from local farmers and Trelleborg municipality  The Tullstorpsåproject

  • Overall goal:

    • Reduce nutrient leakage

    • Good ecological status

    • Reduce flooding

    • Facilitate management

  • Reduction of nutrients

    • N: 30 %

    • P: 50 %

Planned wetland locations

Nr


Master thesis by jan petersson linnaeus university kalmar

  • Water flow

  • N & P concentrations

Potential retention N &P

Methodology

MIKE BASIN

Mathematical modells for N and P retention in wetlands

(Wittgren et al. 2001; Tonderski et al. 2005)

River Basin District Authority´s

Hydrologi and water qualitymodel

  • Differential equations

  • Calibrated against real wetlands in the southern part of Sweden.

  • Retention dependent on:

    • Water flow

    • Water temperature

    • Incoming N- & P conc.

    • Wetland area

    • Wetland volume

Costal area of Skåne


Master thesis by jan petersson linnaeus university kalmar

  • Limitations

  • Only 22 out of 49 wetlands included

  • Wetlands located outside the defined catchment of Tullstorpsån in MIKE BASIN

  • The methodology can’t include the effect upstream/downstream wetlands

Final configuration in MIKE BASIN

Methodology

Estimation of catchments

  • Data from the municipality of Trelleborg (field and map studies)

  • Estimation via topographical data within the model (resolution 50x50 m)

Wetland catchments

Catchments defined by Trelleborg


Master thesis by jan petersson linnaeus university kalmar

Methodology

Estimation of catchments

  • Data from the municipality of Trelleborg (field and map studies)

  • Estimation via topographical data within the model (resolution 50x50 m)

Wetland catchments

Catchments defined by Trelleborg

  • Limitations

  • Only 22 out of 49 wetlands included

  • Wetlands located outside the defined catchment of Tullstorpsån in MIKE BASIN

  • The methodology can’t include the effect upstream/downstream wetlands

Final configuration in MIKE BASIN


Master thesis by jan petersson linnaeus university kalmar

Results

  • Catchments: 11 - 442 ha

  • Simulated Water flow: 70 – 2700 m3 d

  • Mean residence time: 2 – 206 days (mean 21 d)


Master thesis by jan petersson linnaeus university kalmar

P

0,2 – 0,3 mg L

(mean 0,21)

Results

Simulated concentrations

N

5 – 9 mg L

(mean 7,1)

Measured

1990-2006

Mean: 8,6 mg L

Measured

1990-2006

Mean: 0,16 mg L


Master thesis by jan petersson linnaeus university kalmar

Results

Calculated retention

N

P

Specific

60 – 600 kg ha y

(mean 270)

Relative

4 – 70 %

(mean 13 %)

Specific

2 – 20 kg ha y

(mean 12)

Relative

7 – 80 %

(mean 35 %)

  • Literature review

  • 30 – 3000 kg ha y

  • Arheimer &

    Wittgren (2002)

  • 60 – 500 kg ha y

  • Literature review

  • 5– 700 kg ha y

  • Tonderski, Arheimer

    & Pers (2005)

  • 4– 15 kg ha y


Master thesis by jan petersson linnaeus university kalmar

Simulated wetlands (17 ha) + other (57 ha)

 N reduction: 11300 kg, 12 %

 P reduction: 570 kg, 38 %

  • The Tullstorpså project

  • Nutrient reduction goal:

  • N: 30 %

  • P: 50 %

Results

Effect on the total N & P load from the catchment of Tullstorpsån

Total simulated load from the catchment of Tullstorpsån:

94000 kg N, 1500 kg P


Master thesis by jan petersson linnaeus university kalmar

Optimization

  • Possibility to optimize the retention?

  • The hydraulic load (eg. water load per unit area) important factor

  • High values combined with high concentrations positive for the retention

  • but to high  risk of resuspension of sediments and leakage of nutrients

  • The wetland P-retention model

  • Includes this information, when

  • Water Volume in > wetland volume  no retention

  • The wetland N-retention model

  • Doesn’t include this, but its recommended that the retention time should be greater than 2 days

  • Optimization

  • Adjustment of the wetland area (effects the hydraulic load and the retention time)


Master thesis by jan petersson linnaeus university kalmar

Reduction of total load

N: 3400  1900 kg

P: 160  80 kg

Mean reduction per ha

N: 270  470 kg

P: 12  19 kg

~60 % increase

>50 % decrease

Optimization- results

  • Substantial reduction of the wetland area

  • total simulated wetland area decreased with > 70 %

More effective retention, if the wetlands were smaller but at the same time greater in number


Master thesis by jan petersson linnaeus university kalmar

Discussion

The result should be viewed as general guide lines

  • MIKE BASIN

  • Assumption within the model

  • Input data to the model

Uncertainties

  • Wetland retention models

  • No consideration for

  • The wetland design (except area and volume)

  • Plant composition


Master thesis by jan petersson linnaeus university kalmar

Summary

  • The planned wetlands…

  • Have the potential to reduce large amounts of N & P from Tullstorpsån

  • Could be optimized with respect to there hydraulic load

  • Smaller but in greater numbers  more effective reduction of N & P


Master thesis by jan petersson linnaeus university kalmar

Thanks for your attention!

[email protected]


  • Login