Nutrient Transport Modelling in the Daugava River Basin - DiVA Portal

More documents

Recommendations

Info

Figure 1. The hydrological part of the GWLF model.3. MATERIALS AND METHODS3.1 SITE DESCRIPTION – THE DAUGAVA RIVER BASIN3.1.1 Geography and hydrographyThe Daugava River is the third largest river in the Baltic Sea basin (Lundin, 2000). Theriver begins in the western part of Russia and flows through Belarus and Latvia where itenters the Baltic Sea in the Gulf of Riga (figure 2). The total length of the river is 1 005km (Klavins et al., 2002). The river basin has a small difference of elevation within thebasin. Only a few hills are higher than 250 m above sea level (Ziverts, 1999). Thecatchment area is 85 900 km 2 (Hannerz and Destouni, 2005) and it is thus by definitiona large river basin (Klavins et al., 2002). 32 % of the area belongs to Russia, 39 % toBelarus and 27 % to Latvia. The remaining 2 % of the basin belong to Estonia andLithuania (Hannerz and Destouni, 2005).4
Figure 2. The Daugava River Basin.The Daugava basin borders with the catchments of River Gauja in the northwest, LakePeipsi and Lake Ilmen in the north, the Rivers Volga and Dniepr in the east, RiverNemunas in the south and southeast and River Lielupe in the west. There are 5 000tributaries and 95 % of them are less than 5 km. The width of the river varies between12 and 300 m (Jourakova, 2003). Lake Dvineca in Russia is the origin of the river andhere the river is only about six to eight metres wide (Rozins, 2001).3.1.2 Hydrology and climateThe Daugava River has a mixed feeding from rain, snowmelt water and groundwater.Snowmelt water is the most important contributor as it composes 5055 % of the riverdischarge. Accordingly more than half of the river discharge takes place during springflood (Klavins et al., 2002). Daugava contributes about 5 % of the total water inflow tothe Baltic Sea. The annual precipitation decreases from west to east and varies between600 and 800 mm/year (Ziverts, 1999). 75 % of the part of precipitation that falls as rainfalls between April and October (Jouravkova, 2003). The monthly average temperaturevaries between about 5 °C in January to about 17 °C in July (BALTEX HydrologicalData Centre data base, 2004). The climate can be characterised as humid andprecipitation usually exceeds evapotranspiration (Klavins et al., 2002). In figure 3 themonthly average temperature and precipitation in the basin is displayed.5
Page 1 and 2: UPTEC W05 009Examensarbete 20 pFebr
Page 3 and 4: Nyckelord: avrinning, näringsämne
Page 6 and 7: APPENDIX C. DETERMINATION OF POTENT
Page 8 and 9: simulation system CatchmentSim. The
Page 12 and 13: TemperaturePrecipitation20.00120deg
Page 14 and 15: 3.2 MODEL DESCRIPTION3.2.1 An overv
Page 16 and 17: Groundwater discharge to the river
Page 18 and 19: Groundwater nutrient loadsThe groun
Page 20 and 21: There is therefore no guarantee tha
Page 22 and 23: a) Streamflow, calibration periodb)
Page 24 and 25: 4.2 IMPACT OF THE CURVE NUMBER ON N
Page 26 and 27: the chosen value is a very rough ap
Page 28 and 29: all cultivated land will have winte
Page 30 and 31: HELCOM, 2004a. 30 years of protecti
Page 32 and 33: Appendix A. Input data and paramete
Page 34 and 35: Description of parameter/input Name
Page 36 and 37: Description of parameter/input Name
Page 38 and 39: moisture.Figure B1. Selection of cu
Page 40 and 41: wherea t = rainfall erosivity coeff
Page 42 and 43: Appendix F. Regression lines of rep

Nutrient Transport Modelling in the Daugava River Basin - DiVA Portal

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?