The River Glomma from a scientific perspective. Stig A. Borgvang, NIVA

Transcription

1 The River Glomma from a scientific perspective Stig A. Borgvang, NIVA

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3 Justification for the STRIWER case basins The Glomma-Lågen study was one of the The World Commission on Dams (WCD) 10 case studies of dams in major river basins around the world. The basin was also one case basin in the UNEP MILLENNIUM ECOSYSTEM ASSESSMENT PROJECT Norway is one of the world's major dam-building nations, particularly for hydropower development (WCD, 2000). IWRM focused only on reservoir issue (and flooding prevention eg Flood Mitigation Commission after 1995 flooding), but other IWRM elements are missing Scenarios (UNDP MEAP, 2003) Data-rich (WQ,Q, temp, precip, sector data) and data readily available e.g. JOVA agricultural catchments monitoring (Jordforsk), riverine loads RID (NIVA), lake water quality data (NIVA), freshwater biological data (NIVA/NINA)

4 Cont d Available operational water discharge model Experience in flooding prevention (spatial management structure and early warning systems) Successful co-operation with stakeholders Divergent views between environmental authorities/fishery interests and the power companies/water management associations Successful pollution mitigation measures in the 1970s (Lake Mjøsa Action) Usage of projects results and planned projects (synergies): Current study area for Mgt. large catchments SIP (NIVA), planned study area for Climate SIP (CICERO), Scenario SIP (NINA) and economical valuation (NIVA), Lake Vansjø (NIVA)

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12 Catchment details The catchment area of the Glomma and Laagen rivers is km 2 and covers 13 % of Norway's total land area, equivalent to the size of Denmark. The area extends 600 km from North to South and has an annual discharge of million m 3. The area offers great geographical variety, with approximately 30 % being situated more than 1000 m above sea level and approximately 40 % between 500 and 1000 m above sea level.

13 Cont d The mean annual flow close to the river mouth is /s. In the lower parts of the catchment, the water flow may vary from 150 to 3 500m 3 /s during the year. Annual precipitation in the area as a whole range from 260 to 1050 mm. Approximately 15 % of Norway's population of 4.5 million live within the catchment area Only 16% regulation capacity (16 % of the water flow can be stored in the reservoirs)

14 Høyegga Øyeren Funnefoss Solbergfoss Sarpsfossen

15 Glomma Nitrogen concentrations at four river stations

16 Phosphorus concentrations at a river staion in

17 Øyeren lake station Chlorophyll-a and phosphorus concentrations

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20 The Lake Mjøsa- description Mjøsa is Norway's largest lake. It is located in the southern part of Norway, about 100 km north of Oslo. Its main tributary is Gudbrandsdalslågen in the north; the main distributary is Vorma in the south. From its southernmost point at Minnesund in Eidsvoll to its northernmost point in Lillehammer it is 117 km long. At its widest, near Hamar, it is 15 km wide. It is 365 km² in area and its volume is estimated at 56 km³; normally its surface is 123 meters above sea level, and its greatest depth is 468 meters. Its total coastline is estimated at 273 km, of which 30% is built up. Dams built on the distribuary of Vorma in 1858, 1911, 1947, and 1965 raised the level by approximately 3.6 meters in total. In the last 200 years, 20 floods have been registered that added 7 meters to the level of Mjøsa. Several of these floods inondated the city of Hamar.

21 Mjøsa- details Area: 362 km 2 Length: 117 km Lillehammer - Minnesund. Greatest witdh: 16 km Hamar - Totenvika. Max. depth: 453 m, 330 metres below sea level. Average depth: 153 m theoretical residence Residence time 5,6 years. Altitude above sea level: approx. 123 m Amount of water: mill m 3 Municipalities: Hedmark County: Ringsaker, Hamar,

22 Total phosphorus in the Lake Mjøsa

23 A success story for water management in Norway Tot-P µg/l Middelkonsentrasjon for perioden juni-oktober

24 The Atna water course, a tributary to Glomma

25 Conductivity in the Atna water course 4 ATNA I og II 80 3,5 3 kond I kond II Q II , , , JAN FEB MAR APR MAI JUN JUL AUG SEP OKT NOV DES 0

26 Water flow in the Atna water course Q m³/s

27 Nitrate concentrations in the Atna water course 240 ATNA I og II NO3 I NO3 II Q II JAN FEB MAR APR MAI JUN JUL AUG SEP OKT NOV DES 0

28 Distribution and occurrence of selected species of cyanobacteria along the River Atna occurrence (0,1-1) 1 0,8 0,6 0,4 0,2 0 Phormidium sp 2 st.1 st.2 st.3 st.5 st.6 st.7 st.8 occurrence (0,1-1) 1 0,8 0,6 0,4 0,2 0 Chamaesiphon subglobosus st.1 st.2 st.3 st.5 st.6 st.7 st.8 occurrence (0,1-1) 1 0,8 0,6 0,4 0,2 0 Scytonematopsis starmachii st.1 st.2 st.3 st.5 st.6 st.7 st.8 occurrence (0,1-1) 1 0,8 0,6 0,4 0,2 0 Schizothrix latierita st.1 st.2 st.3 st.5 st.6 st.7 st.8 occurrence (0,1-1) 1 0,8 0,6 0,4 0,2 0 Chamaesiphon fuscus st.1 st.2 st.3 st.5 st.6 st.7 st.8 occurrence (0,1-1) 1 0,8 0,6 0,4 0,2 0 Cyanophanon mirabile st.1 st.2 st.3 st.5 st.6 st.7 st.8 1 Calothrix gypsophila 1 Clastidium setigerum 1 Stigonema mamillosum occurrence (0,1-1) 0,8 0,6 0,4 0,2 0 st.1 st.2 st.3 st.5 st.6 st.7 st.8 occurrence (0,1-1) 0,8 0,6 0,4 0,2 0 st.1 st.2 st.3 st.5 st.6 st.7 st.8 occurrence (0,1-1) 0,8 0,6 0,4 0,2 0 st.1 st.2 st.3 st.5 st.6 st.7 st.8

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30 Periphyton is a complex matrix of algae and heterotrophic microbes attached to submerged substrata in almost all aquatic ecosystems. It serves as an important food source for invertebrates and some fish, and it can be an important sorber of contaminants. Periphyton is also an important indicator of water quality; responses of this community to pollutants can be measured at a variety of times scales representing physiological to community-level changes. Monitor temporal changes in periphyton biomass and photosynthesis in response to remedial actions Characterise stream conditions for periphyton growth Identify potential roles of periphyton in contaminant movement into stream food webs