(1) Research Institute for Humanity and Nature
(2) Institute of Observational Research for Global Change
(3) Institute of Observational Research for Global Change/Hokkaido Univ.
(4) State Hydrological Institute
Siberia, which is located in the northern part of the Eurasia continent, has the widest permafrost area on earth. Discharges by big rivers in Siberia play an important role as fresh water supply to the Arctic Sea, affecting not only the hydrological and thermal conditions of the Arctic Sea, but also the polar region climate. To understand water and energy cycle in Siberia, An intensive field campaign was carried out at a small watershed on the watershed-divide of the Lena and Amur rivers in the southern mountainous region. The dominant species are larch, birch and pine. Both the catchment scale hydrological observation including time and spatial distribution of thawing depth and soil moisture and the observation of water and heat exchanges between land surface and atmosphere on several surface conditions within the watershed, including snow processes, were carried out from August 2000 to June 2002.
The amounts of precipitation, discharge, evapotranspiration by flux measurement and interception loss, in the warm period from April 19 to October 13, 2001 were 434.5mm, 204.1mm, 127.5mm, and 82.6mm, respectively. According to measurements of transpiration by the sap flow method and the evaporation from forest floor, the contribution of the evaporation from forest floor was significant, around 80% of the total. The Bowen ration after the snowmelt in the middle of April was around 1.0 Just after the opening leaves at the beginning of June, it slightly decreased due to transpiration, and then began to increase at the end of August. The contribution of snow surface evaporation to snow ablation was nearly 8.7% during a thaw of 2002. During an early spring, the soil heat flux was important energy for snow evaporation. The most effective energy to snowmelt was net radiation because the most of turbulent fluxes were negative value to the snowmelt energy.
Submittal Information
Name :
Date :
Jumpei Kubota
28-Jul-04-10:21:30
Organization :
Theme :
Research Institute for Humanity and Nature
Theme 1
Address :
Presentation :
335, Takashima-cho, Kamigyou-ku, Kyoto 602-0878, JAPAN