The Hypertrophic Estuary of Mariager Fjord: Pollution of CoastalWaters

Gheorghiu, Ovidiu-Constantin ; Iordachescu, Lucian ; Løvgaard, Andreas ; Antony, Johny Dilan ; Casas Cardona, Laura ; Delso Martinez, Javier

2. term

Water and Environmental Engineering , Master

2015

2015-06-03

71

Mariager Fjord er et estuarie med kraftig eutrofiering, dvs. for mange næringsstoffer (kvælstof og fosfor) fra de omkringliggende vandløb. Det giver omfattende algevækst og kan føre til iltsvind, og ifølge Aquatic Plan 1.3 [2011] vurderes vandkvaliteten som dårlig. EU’s Vandrammedirektiv [2000] kræver, at alle europæiske vandområder opnår god tilstand senest ved udgangen af 2015. I denne rapport undersøges, hvordan reduktion af næringsstoffer kan forbedre fjorden, ved at opstille en økologisk model (der simulerer alger, ilt og næringsstoffer) og en hydrodynamisk model (der beskriver vandets bevægelse). Vi afprøver scenarier med lavere tilførsel af kvælstof og fosfor og ser, hvordan den økologiske model reagerer. Desuden vurderes en konceptuel løsning, der kan forbedre vandkvaliteten. Resultaterne peger på, at kvælstof kan reduceres med de foreslåede tiltag, men at kravene for 2015 næppe kan nås i tide. God vandkvalitet kan dog være mulig i den nærmeste fremtid, hvis reduktionerne gennemføres.

Mariager Fjord is a highly eutrophicated estuary—that is, it receives too much nitrogen and phosphorus from nearby streams, which fuels algae and can deplete oxygen. According to Aquatic Plan 1.3 [2011], its water quality is rated as bad. The EU Water Framework Directive [2000] requires all European waters to reach good status by the end of 2015. This report examines how reducing nutrients could improve the fjord by building an ecological model (simulating algae, oxygen and nutrients) and a hydrodynamic model (describing water movement). We test scenarios with lower inputs of nitrogen and phosphorus and observe how the ecological model responds. A conceptual solution to improve water quality is also assessed. The findings indicate that the proposed measures can reduce nitrogen, but the 2015 target is unlikely to be met in time. However, good water quality may be achievable in the near future if reductions are implemented.

[This abstract was generated with the help of AI]

eutrofiering ; Mariager Fjord ; økologisk ; hydrodynamisk ; model ; næringsstoffer

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Løvgaard, Andreas:

• Modelling of surface runoff from green areas (2016)

Antony, Johny Dilan:

• Storm surge protection of the Limfjord: Closure of Thyborøn Channel (2016)

Casas Cardona, Laura:

• Analysis of urban catchment for flood return period assessment (2016)

Delso Martinez, Javier:

• Hydrological characterization of cessation of flow periods in temporary rivers: A methodology assessment performed in the Guadiana Basin (2016)