Both winter DJF （December, January, February） months and DJF season means long-term data series of 50 regulated rivers discharges rates and the NAO indices were analyzed for different spans. This study is dictated ...Both winter DJF （December, January, February） months and DJF season means long-term data series of 50 regulated rivers discharges rates and the NAO indices were analyzed for different spans. This study is dictated for： （1） detecting the exclusive impacts of the positive phases of NAO indices on rivers discharges rates by estimating the Linear Correlation Coefficient; （2） modeling the interrelations between the discharges rates and NAO indices by estimating the Linear Regression Models, both for manifesting the impact of the positive phase of NAO index; （3） estimating the Linear Trend Coefficient in the discharge series, for manifesting the contribution of the positive phase of NAO index. Discharge rates are mainly influenced by the two mechanisms： the positive phase of NAO index and the environmental conditions in specific catchments, that is where, the positive phase of the NAO index manifest its impact on the related rivers discharges and its contribution in the related configured trends. The discharges fluctuations patterns show some increase in the discharges values have been occurred in regions around the Northern Baltic Proper as well as in Southern Finland and Sweden. The rivers such as Lagan, Nissan, Helgean, Venta, Pamu, Porvoonjoki, Lapuanjoki, Oulujoki, Kyronjoki, Wisla, Eurajoki, Odra, Lielupe, Gota alv, Motala strom, Nykopingsan, Vuoksi, Kalajoki and Simojoki haven not linear discharges changes registered depending on the specificity of the environmental conditions at the catchments areas for those rivers. The positive phase of NAO index has a linear relation with impacted river discharge.展开更多
文摘Both winter DJF （December, January, February） months and DJF season means long-term data series of 50 regulated rivers discharges rates and the NAO indices were analyzed for different spans. This study is dictated for： （1） detecting the exclusive impacts of the positive phases of NAO indices on rivers discharges rates by estimating the Linear Correlation Coefficient; （2） modeling the interrelations between the discharges rates and NAO indices by estimating the Linear Regression Models, both for manifesting the impact of the positive phase of NAO index; （3） estimating the Linear Trend Coefficient in the discharge series, for manifesting the contribution of the positive phase of NAO index. Discharge rates are mainly influenced by the two mechanisms： the positive phase of NAO index and the environmental conditions in specific catchments, that is where, the positive phase of the NAO index manifest its impact on the related rivers discharges and its contribution in the related configured trends. The discharges fluctuations patterns show some increase in the discharges values have been occurred in regions around the Northern Baltic Proper as well as in Southern Finland and Sweden. The rivers such as Lagan, Nissan, Helgean, Venta, Pamu, Porvoonjoki, Lapuanjoki, Oulujoki, Kyronjoki, Wisla, Eurajoki, Odra, Lielupe, Gota alv, Motala strom, Nykopingsan, Vuoksi, Kalajoki and Simojoki haven not linear discharges changes registered depending on the specificity of the environmental conditions at the catchments areas for those rivers. The positive phase of NAO index has a linear relation with impacted river discharge.
