DaNUbs Project results Lessons learned for Black Sea Water Quality Mangaement Helmut Kroiss,...

DaNUbs Project results

Lessons learned for Black Sea Water Quality Mangaement

Helmut Kroiss, Matthias Zessner, Christoph Lampert Institute for Water Quality, Ressource and Waste

Management Vienna University of Technology

Varna meeting June 2005

"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel

Eutrophication abatement in Black Sea Coastal areas

Some basic relationships for better understanding the role of nutrients

(N, P, Si)

Algae productionNatural sources

N

P + light + CO2 organic solids

sediment

O2 (surface)

organic matter + O2 CO2 + H2O + biomasse

Breakdown of organic matter

food chain

fishery release of N and P to water

removalto atmosph.(DN)

transport and storage with water

fixation in sediments (long term)

anthropogenicsources of

N and P


Mass flow of nutrients N and/or P [Mg/a] represents a potential for primary production in rivers and the sea

Concentration of one essential “nutrient” and/or solar energy availability limits growth (use of the potential)

ratio of «nutrients», fishery and solar enery availability infuence competition between species and natural food chaines.

Human activity leads to import of foreign species (jelly fish) and waste (water) discharges (new substances or inhibitors)


Data quality assessment and related problems

Data interpretation

The basic data for all considerations regarding the role of nutrient fluxes are concentrations in the water and flow.

The most reliable data are those for dissolved (inorganic) nutrients.

Data are much less reliable in regard to particulate and

organically bound nutrients.


Data interpretation

The measured values are already the result of the following processes and their related history:

• Natural nutrient input• Anthropogenic input• Primary production (sunlight, climatic conditions)• Release of nutrients from breakdown of organic

solids (including denitrification)• Transport phenomena, intermediate storage• “final” storage in sediments (e.g. deep sea)

Data interpretation

All these processes are subject to strong variations over time (day, season, year, decades) and are strongly influenced by specific local and regional conditions.

There are much less reliable data on particulate nutrient compounds. Their interpretation is even more difficult than for the dissolved compounds.

The basic consequence of these statements is:

Interpretation of measured concentrations and calculated fluxes (loads) without understanding the processes involved is very limited and can be even completely misleading

Specific local and regional conditions Natural conditions:• Geology• Morphology (e.g. slope)• Climate (temperature, precipitation, latitude)

Anthropogenic influences (past decades, actual, future)• Agriculture

Crops Volume of production Animal production (volume and density) Practice (fertilizing, manure handling) Water and waste water management (municipal, industrial,

storage) Air pollution (incineration, traffic)

plants

animals

Specific local and regional conditions

Natural:• Geology• Morphology (e.g. slope)• Climate (temperature,

precipitation, latitude)

Anthropogenic:• Water management• Air pollution abatement • Agricultural practice

quality

quantity

land use

Scenario developmentand assesment for different

options of „policy“

Historic development of policy, economy, technology, science

Specific local and regional conditions

Using the information about the • natural conditions and • knowing the relation between the natural conditions, the • anthropogenic influences and • their effect on the nutrient fluxes

different scenarios can be developed which include economical, political and technological tools.


Management tools

• After an assessment of “bearable nutrient loads for WBSC” a decision has to be made for the implementation of a combined approach strategy including – precautionary principle (legal framework on

minimum criteria, e.g. UWWD, good agricultural practice, enhanced by economical incentives, etc.)

– environmental quality criteria for additional measures based on cost effectiveness

Assessment of the actual state of WBSC Strong improvement during the last decade

Indicators for this improvement are:

• Anaerobic conditions in sediments (anoxia) have nearly disappeared

• Marked increase of number of macrobenthic species

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

• Rare algae blooms (similar to the 1960ies)

• Red algae in NWBS bottom area in depth up to 40 m


20

22

24

26

28

30

32

34

36

38

40

1988 1996 1999 2000 2002

Period

Nu

mb

er

of

sp

ec

ies

Number of macrobenthic species in front of the Danube delta showing an increase of species since 1996 (10 stations on 3 transects off Constanta) data from C. Domitrake.


• The anaerobic conditions at the bottom of WBSC, clear indicators of eutrophication, have nearly completely disappeared. The situation is close to the sixties now.Only the fish stock is still out of balance. This is mainly a result of inadequate fishing.

• P is the limiting factor for eutrophication of the Black Sea. Therefore efforts should continue to reduce P emission.


A B

A. SeaWiFS Satelliten Bild des Westlichen Schwarzen Meeres von 7 May 2000. B. Summenbild (ca. 800 Satellitenaufnahmen 1998-2002) des westlichen Schwarzen Meeres mit (rote Linien) Ausdehnung gemäßigter und intensiver Algenblüten wie sie in den 1980ger Jahren beobachtet wurden (nach Zaitzev 1992)


Geringe Ausdehnung der Eutrophierungszone - südlich des Donau Deltas sowie niedrige Nährstoffkonzentrationen in unmittelbarer Nähe des Eutrophierungsgebietes im September 2002. .


January 1998-2003

February 1998-2003

March 1998-2003

April 1998-2003

May1998-2003

June 1998-2003

July 1998-2003

August1998-2003

September 1998-2003

October 1998-2003

November 1998-2003

December1998-2003

Monatliche Mittelwerte von mittleren (> 1.38 mg m-3) und hohen (>5 mg m-3) Chlorophyllkonzentrationen im westlichen Schwarzen Meer aus SeaWiFS Satelliten Aufnahmen (Davidov 2004).


1

2 3

200 m

29.0 30.0 29.0 30.0

43.8

44 .2

44.6

45.0Danube

September 1996

80

7060

50

606

0

60

60

50

50

40

30

Danube

September 1999

100

100

120

120

120140140

80

80

29.0 30.0

September 2003

Danube

100

100

100

90

90

80

80

70

Sauerstoff arme Gebiete im Flachwasser des nordwestlichen Schwarzen Meeres von 1974 bis

1983 und die Verbesserungen der Sauerstoffverhältnisse in Bodennähe zwischen 1996 und 2003.


Im September 2004 wurden vor der ukrainischen Küste wieder größere Bestände der Rotalge Philophora beobachtet.


The improvement is caused by reduced nutrient inputs by Danube River.

Transported phosphorus loads are reduced to about 50 % as compared to the situation around 1990.

Phosphorus is the limiting nutrient now for algae growth which seems to be the main reason for improvement of marine ecology in the WBSC.

Nutrient transport from catchment to Black Sea

Actual situation

• P discharge to WBSC has decreased by about 50% compared to the early 1990ies, the situation is comparable to the 1960ies

• N discharge has markedly decreased, probably by about 30%, data consistency makes problems

• Slow trend towards lower nutrient loads from Germany and Austria

A strong decrease in nutrient point and diffused emissions in Eastern Danubian Countries (EDC), but

an increase can be anticipated due to an increasing use of market fertilizers to reach economic sustainability in agriculture


Deviation load calculated to load observed for 1998-2001:

20% for DIN

Assumptions:

BG & 50‘s: 50%

1975: 50%

1980 to 90: 30%

1995 to 99: 20%


Deviation load calculated to load observed for 1998-2001:

29% for TP

Assumptions:

50‘s: 60%

1975: 50%

1980 to 90: 40%

1995 to 99: 30%

Nutrient transport from catchment to Black Sea

Actual situation

The main causes for this positive development are:

• Economic crisis in EDC countries since 1989

• Change of agriculture from economically driven production to nutritional survival of the population, closure of the large animal production plants and of fertilizer industry (market fertilizer application close to zero)

• 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

(i) MONERIS

(ii) DWQM

(iii) DDM

(iv) Shelf Model

(i) nutrient balancesagriculture, nutrition, diffuse

pollution etc.

(ii) transportin rivers

(iii) Effects onBlack Sea

Emissions to surface water

In stream transports, fluxes to Delta

Fluxes to Black Sea

Sources, pathways and stocks in the catchment

Critical nutrient loads

(i) Handbook fornutrient balances

(ii) scenarioevaluation

Processunderstanding

Legend:

Model Strategicplanning

Results

(I.) (II.) (III.)

Solutions for nutrientmanagement

MODELLING

s


Schematic of model simulations connectivity and data flow


Regional differences of nitrogen emission via groundwater to surface waters


Regional differences of back ground loads in the Danube Basin

Wastewatermanagement;

22%

Background; 25%

Agriculture; 45%

Combustion and traffic; 8%

Sources of nutrient emissions 1998-2000 into the Danube

Total Nitrogen

Background

Background;9%

Combustion and traffic; 3%

Agriculture; 43%

Total Posphorus

Sources of nutrient emissions 1998-2000 into the Danube

Wastewatermanagement;

45%


The current relatively low discharges of N and P to the Black Sea are to a certain degree a result of the economic crisis in the former communist countries (EDC) resulting in:

a dramatic decrease of the application of mineral fertilizers,

the closure of large animal farms (agricultural point sources) and the

closure of nutrient discharging industries (e.g. fertilizer industry).


} 2.21.1

The TP load in the Danube in the period 1983-1987 was 2.2 times higher than in the 50‘s.

The present TP load is only 1.1 times higher than in the 50‘s.

Without Iron Gate the present TP-load would be 1.5 times higher than in the 50‘s

Iron Gate

Driving forces for N, P emissions to water system in agriculture:

a: Anthropogenic

• Fertilizer management in plant production

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

• Soil quality management, erosion abatement, etc.

• Economic competitiveness of agricultural products

b: Natural

• Soil geology

• Precipitation (amount, distribution)

• Climatic conditions

• 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).

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

• Erosion together with overfertilisation contributes to transport of particulate nutrient loads, The role of particulate nutrient loads in the Black Sea Coastal Area may depend on the easily accessible nutrient loads as primary eutrophication potential. In case of anoxia at the sea bottom, nutrient release from the sediments represents an unpredictable additional potential for eutrophication.


Scenario calculationsEntwicklung der Phosphoremissionen im Donaueinzugsgebiet

0

20

40

60

80

100

120

140

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 1 2

rive

r lo

ad

s a

nd

em

issi

on

s [1

00

0 tP

/a]

diffuse emissionsindustrial and agricultural point sourcesmunicipal point sources

scenarios:1: UWWD without P-removal2: UWWD with P-removal

Danube river load

Conclusions

• Good data quality and adequate data availability are basic requirements for the development of rational water quality management strategies.

• Understanding the transport, storage and transformation processes of “pollutants” from their source to the receiving sea and their effects on aquatic ecosystems (and other environmental compartments) is necessary for data interpretation

• Mathematical modelling is a useful tool :• to improve the application of our knowledge and

experience (understanding) to answer specific questions for complex systems

• to validate our knowledge and/or evaluate data quality

Conclusions

• Model results can never be “better” than our understanding and the quality of the data we use for calibration

• Validation of models for complex systems becomes less reliable the better the model simulates reality i.e. the more processes (parameters) are included

• Black Sea Quality management strategy can never be developed from Black Sea data alone, even monitoring program is extended and improved.

• Pollution has to be controlled as close to the sources as possible. For this statistical database have to be exploited using mass balance methodology.

Conclusions

• Reliable long term historic data from catchment and Black Sea are necessary for the interpretation of the actual state

• Climatic conditions (including climate change) play a decisive role for transport and transformation of all “pollutants”

• A great variety of economic and political tools to influence on the emissions and to avoid pressure on the environment are available. They have to be assessed according to their cost effectiveness under the different specific regional circumstances.

• Water quality management on a catchment scale needs a long lasting strategy for sustainable development with a prospective of about 30 years for stable success.

Conclusions

• Precautionary and environmental principle have to be combined in order to achieve optimal cost and environmental effectiveness.

• A consistent methodology is needed to trace “pollution” loads (sources, pathways, storage and losses) from their source to the Black Sea consisting of mass balances and dynamic models combining the hydraulic, hydrological and biological processes in the catchment, the rivers and the Black Sea.

• Decision making needs consent of stakeholders even there are sound scientific analyses and reliable modelling results


Danubs Team

DaNUbs Project results Lessons learned for Black Sea Water Quality Mangaement Helmut Kroiss,...

Documents

Transcript of DaNUbs Project results Lessons learned for Black Sea Water Quality Mangaement Helmut Kroiss,...