Nutrient management in Danube river basin for eutrophication control in Western Black

Sea Coastal Area

Kishnev, Oct. 2006

H. Kroiss, M. Zessner, Ch. Lampert

Institute for Water Quality and Waste Management,

Vienna University of Technology

Introduction

In many regions of the world problems with eutrophication of marine estuaries occurs due to excessive discharge of nutrients (N, P) by large rivers.

This eutrophication problem is mainly caused by diffused sources (land use, agriculture) and inadequate waste water management.

The daNUbs Research Project within the 5th European Research Frame Work Program dealt with this problem in regard to the Danube River Basin and Black Sea coastal area.

Danubs Team

Characteristics of the study region Danube and Western Black Sea Shelf Area, WBSS

DANUBE RIVER

Length: 2.857 kmCatchment 817.000 km², incl. larger parts of 13 countries

Population within the catchment: 85 million people

BLACK SEA

Total catchment: 2.3 million km², population 190 million peopleSurface Area: 461.000 km², average depth 1.240 m

WESTERN BLACK SEA SHELF AREA

Influenced by Danube plume; surface area about 30.000 km²Depth along the coastline: ~70 m, shelf ~140 m

MACEDONIA

SLOVAKIA

GERMANY CZECH REPUBLIC

SLOVENIA

HUNGARY

CROATIA

BOSNIA &HERZEGOVINA

ALBANIA

BULGARIA

SWITZERLAND

ITALY

UKRAINE

MOLDOVA

ROMANIA

YUGOSLAVIA

Brno

München

BratislavaWien

Zagreb

Budapest

Kyiev

Ljubljana

AUSTRIA

Bucharest

Sarajevo

Sofia

Belgrade

POLANDPrague

Chisinau

State border

Coast line

Danube

Main River network

Border of the basin

City Danube River Basin

REP: SERBIA

daNUbs– Project Goals

• Understanding of the fate of nutrients (N, P, Si) from their sources (point and diffused sources) to the sea

quantitative description by: Source inventory, MONERIS, Danube Water Quality Model, Danube Delta Model.

• Understanding of the relation between river nutrient discharge and the eutrophication processes in WBSSA.

quantitative description by: physical ocean model, biological models of the shelf area influenced by Danube

daNUbs– Project Goals

• Development of technical and operational measures to control point and diffuse nutrient discharges to the environment in order to achieve sustainable good water quality in Danube and WBSSA

• Design of different scenarios in order to show the link between political and socio-economic development (decisions) and the consequences for the status of all waters in Danube Basin as required by EU WFD (special emphasis on WBSSA).

• Development of improved monitoring procedures.

CONCEPT

EUTROPHICATION

N PSi?

DISPOSAL

TRANSPORT

TRANSFORMATION

STORAGE

NUTRITION

LIFESTYLE

AGRICULTURE

ECONOMY

Emissions Danube Basin

Black Sea

SOCIO ECONOMIC ASPECTS

PROJECT METHODOLOGY

• MONERIS model, describes the transport and transformation of nutrients from their source to the river system

• DWQ-model, describes the same processes in the large rivers

• DD-model, describes the fate of nutrients in Danube Delta

• Models are able to describe the consequences of the dramatic changes in the catchment due to the economic crises in the CEE countries for N and P discharge to Black Sea with adequate accuracy for strategic decisions.

Historic development of P-discharge

The main anthropogenic driving forces for N and P discharge to Danube and Black Sea are:

• Agriculture (nutrition, animal protein production)

• Wastewater management (sewerage, wastewater treatment)

• • Air pollution by combustion processes (e.g. traffic) with

NOX.

Nitrogen emissions

Total N-emissions about 700 kt/a(N to Black Sea 420 kt/a (60%))

natural background

8%

agricultural"background"

31%

agriculturereduction potential

14%

urban settlementsreduction potential (UWWD)

11%

urban settlementsrest20%

other diffused sources

16%

hardly to be reduced

can be reduced during next 10 years

can be reduced and increased with a delayof 10 years betweenimplementation and response

Total N-emissions about 700 kt/a(N to Black Sea 420 kt/a (60%))

natural background

8%

agricultural"background"

31%

agriculturereduction potential

14%

urban settlementsreduction potential (UWWD)

11%

urban settlementsrest20%

other diffused sources

16%

hardly to be reduced

can be reduced during next 10 years

can be reduced and increased with a delayof 10 years betweenimplementation and response

D D+P

Phosphorus emissions

total P-emissions about 70 kt/a(P to Black Sea 20 kt/a +

P in Iron Gate 8 kt/a)

naturalbackground

8%

agriculturereduction potential

20%

urban settlements reduction potential

(UWWD)

23%

urban settlements rest33%

other diffused sources

3%agricultural

"background"13%

hardly to be reduced

can be reduced during next 10 years

can be reduced

total P-emissions about 70 kt/a(P to Black Sea 20 kt/a +

P in Iron Gate 8 kt/a)

naturalbackground

8%

agriculturereduction potential

20%

urban settlements reduction potential

(UWWD)

23%

urban settlements rest33%

other diffused sources

3%agricultural

"background"13%

hardly to be reduced

can be reduced during next 10 years

can be reduced

D

P

Nutrient emissions to water system influenced by agriculture:

• Fertilizer management in plant production

• Production of animal protein and fat (milk, meat, eggs)

• Soil quality management, erosion abatement, etc.

• Agricultural Policy (financial support) on national, EU and WTO level

Natural influences on nutrient emissions to water system:

• Soil, geology

• Climatic conditions (precipitation, etc.)

• Slope

• Residence time in groundwater

Driving forces for transport and losses:

• Denitrification potential mainly from source to medium size rivers with strong emphasis on processes in soil and ground water (residence time) and interaction between ground and river water (littoral areas).

• Erosion together with over-fertilization strongly contributes to transport of particulate nutrient loads, their role for eutrophication is still not well understood.

• The large dam at Iron Gate represents and important sink for phosphorus even for the next decades.

• Large rivers (including wetlands along these rivers and the delta) have only little influence on N transport and loss.

Actual Status of Western Black Sea Coastal Area (WBSC)

Indicators for improvement of water quality:

• Anaerobic conditions in the sediments (anoxia) have nearly disappeared

• Number of macro-benthic species in the WBSC has markedly increased

• Algae growth is phosphorus limited (in summer, in winter probably light limited)

• Rare algae blooms (similar to the 1960ies)

Positive development in WBSSA is mainly caused by:

• Economic crisis in Eastern Danubian Countries (EDC) since 1989

– Change of agriculture from economically driven production to nutritional survival of the population,

– closure of the large industrial animal production plants

– closure and of many fertilizer production plants (market fertilizer application dropped to nearly zero) in the EDC countries

• Use of P free detergents in D, A, and increasingly in EDC

• N and P removal at municipal treatment plants in D, A, CZ

• Improved agricultural practice mainly in A, D

Conclusions

• Danube is the main contributor to eutrophication phenomena in WBSC.

• Nutrient concentrations in Danube River will probably meet good status requirements.

• The actual status of WBSSA is close to “good” (except fish population).

• The climatic conditions during the last years were favorable for WBSSA.

• Eutrophication in WBSSA is actually phosphorus limited and the N/P ratio is “good”.

• Economic crises and improved dissolved P management from point sources were the main drivers for the improvements in WBSSA.

• Agriculture is the main driver for diffused nutrient emission to water systems.

• Nitrogen loads which can be influenced by agricultural practice are actually in the same order of magnitude as from point sources (municipal waste water systems).

• For dissolved phosphorus point source are of primary importance, particulate phosphorus mainly stems from agricultural soil erosion.

• The establishment of a clear correlation between measures taken and the response in the status of Danube and WBSSA needs long term reliable monitoring and adequate models.

• Economic situation in the EDC actually not sustainable. Economic development can result in important increase of nutrient discharges from diffused (agricultural development) and point sources (sewerage development without adequate waste water treatment).

• A nutrient management policy for all Danubian countries enabling economic growth without compromising water quality has to be implemented (ICPDR); relation to EU Agricultural Policy

• Changes in climate can lead to increase the pressure.

• Nutrient management needs a long lasting strategy for sustainable development with a perspective of about 30 years for stable success.

Anticipated Pressures for Nutrient Management in Danube Basin

Institute for Water Quality and Waste Management, TU Vienna,AUSTRIA; CO-ORDINATOR

Danube Delta National Institute for Research and Development, Tulcea, ROMANIA

Stichting Waterloopkundig Laboratorium, Delft Hydraulics, Delft, NETHERLANDS

Bureau of Sustainable Agriculture, Hanhofen GERMANY

Institute of Fisheries and Aquaculture - Varna, BULGARIA

Institute for Freshwater Ecology and Inland Fisheries, Berlin, GERMANY

Institute of Hydraulics, Hydrology and Water Resources Management, TU Vienna, AUSTRIA

Institute for Land and Water Management, Petzenkirchen, AUSTRIA

Institute for Marine Research, University Kiel, GERMANY

National Centre for Marine Research, Athens, GREECE

Romanian Marine Research, Constanta, ROMANIA

Institute for Water Pollution Control, Vituki Budapest, HUNGARY

Department of Sanitary and Environmental Engineering, Budapest, HUNGARY

Institute of Public Finance and Infrastructure Policy, TU Vienna, AUSTRIA

Department of Meteorology and Geophysics, University of Sofia, BULGARIA

Institute of Water Problems, Bulgarian Academy of Sciences, Sofia, BULGARIA

Department of Systems Ecology, University of Bucharest, ROMANIA

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