4.1 a) Identify test cases One of the tasks is to evaluate the - - PowerPoint PPT Presentation

4.1 a) Identify test cases

• One of the tasks is to evaluate the effect of measures implemented in

individual river basins. For that purpose, good and bad examples of nutrient load reduction for individual river basins are to be selected.

• The data compiled in the HELCOM PLC database are to be utilized to select

from two to four catchments per HELCOM country. These will be used to compare areas where measures have been particularly effective in reducing nutrient loads as well as those where significant efforts have been made to reduce nutrient inputs, but without apparent success.

• The main criterion is that those rivers show increases or decreases in nutrient
• loads. In addition, it would be beneficial, if following information would be

available:

• main load sources
• catchment properties
• conducted water protection measures

• Countries who have contibuted:

– DK, EE , FI, LV, PL, RU, SE

• No reply:

– LT

• Not willing to participate:

– DE

Denmark

Estonia

Finland

Latvia

Background information also included.

Poland

The Wełna is a river in west-central Poland, a right tributary of the Warta river. The Warta is a river in western-central Poland and a tributary of the Oder.

Suggested rivers Welna and Ina

Russia

“

Sweden

Reference to the B7 report

Background info for the River Råån

• Land use in catchment:
• Lakes and watercourses

<1%

• Forests

5%

• Open areas

10%

• Wetlands

<1%

• Arable land

77%

• Urban areas 6%
• Paved surfaces

2%

• Nutrient sources:
• Nitrogen [%]

Phosphorus [%]

• Lakes and watercourses

<1 <1

• Forests

<1 1

• Wetlands

<1 <1

• Arable land

95 86

• Other

2 2

• Urban areas incl storm water

2 4

• Scattered dwellings

1 6

• MWWTPs

<1 <1

• Industry

<1 <1

• Remedial measures:
• Agricultural measures 2000-2009: Constructed wetlands to increase nutrient retention
• Agricultural measures 2010-2014: Eg. ploughing in spring-time, conversion of intensive arable land to extensively managed grasslands, protective zones to reduce run-off, implementation of catch-

crops

• Urban areas: Within the municipality of Helsingborg (situated at the river mouth) there has since 1991 been extensive constructions of wetlands, reconstruction of rivers to allow flooding (widening
• r construction of a wide upper riparian zone), construction of storm water ponds
• Note! The MWWT of Helsingborg (110 000 pe) is a direct point-source in the Sound.

How to proceed?

• Compilation of background info of all countries

– Collect point source data of the selected rivers

• Estimate the proportion of point sources in trends

– Collect source apportionment data of the selected rivers (if not contributed by countries)

• Estimate the proportion of different sources in PLC-6
• Find driving forces behind increasing/decreasing loads
• What else?