The Lena River report, by Annebeth Korteweg
Characteristics
Length: 4.400 km
Basin area: 2.490.000 km2
Temperature: -60 C in winter to 15 C in summer
Precipitation: southern mountains: 24 to 28 inches
Basin: 8 to 16 inches
Problems
The prolonged cold temperatures cause large accumulations of ice in the form of icy knolls. These are formed of ground waters that accumulate between the layers of soil frozen permanently (permafrost) over many years and layers of seasonally frozen soil. Sometimes the icy knolls disintegrate with considerable force, scattering ice blocks. The riverbeds and flood lands also have permafrost in some places.
Abstract
The Lena is a major river of Russia and one of the longest rivers in the world. It flows 2,734 miles (4,400 km) from its source in a small Siberian mountain lake west of Lake Baikal in Central Asia, northward across Russia, to the mouth of its delta on the Arctic Laptev Sea.
The Lena River basin covers an area of about 961,000 square miles (2,490,000 square km). Its major tributaries include the Vitim, Aldan, Great Patom, Olyokma, and Nyuya rivers. Three main sections form the Lena, each about 900 miles (1,450 km) long: the upper section flows from the source to the Vitim tributary; the middle course from the Vitim to the mouth of the Aldan; and the lower section from the Aldan to the Laptev Sea. The river\'s upper section flows through a deeply cut valley that gradually widens, becoming a large, deep riverbed in the upper half of the middle course. The surrounding slopes are gentle and green with forests, and there is a large water meadow in which many small lakes are scattered. The character of the valley changes sharply in the lower half of the middle course. There the Lena flows along the bottom of a narrow valley; the area is a popular site for tourists and rock climbers.
The river basin of the Lena River
The climatic features of the Lena River basin are determined by its location well inside the continent. In winter the powerful Siberian anticyclone (high-pressure system) is formed, the spur of which occupies all of eastern Siberia. Because of the anticyclone, the winter is notable for its clear skies and lack of wind. Temperatures fall as low as -76° to -94° F (-60° to -70° C), with average air temperature in January ranging from -22° to -40° F (-30° to -40° C). In July averages range between 50° and 68° F (10° to 20° C). Owing to its remoteness from the sea, precipitation in the basin is slight. Only in the southern mountains does the yearly total reach 24 to 28 inches (600 to 700 millimetres); in most of the basin it ranges between 8 and 16 inches, and in the delta it drops to 4 inches. Between 70 and 80 percent of the precipitation falls in the summer in the form of steady rain. Winters average not more than two inches of precipitation, resulting in a light snow cover.
The prolonged cold temperatures cause large accumulations of ice in the form of icy knolls. These are formed of ground waters that accumulate between the layers of soil frozen permanently (permafrost) over many years and layers of seasonally frozen soil. Sometimes the icy knolls disintegrate with considerable force, scattering ice blocks. The riverbeds and flood lands also have permafrost in some places.
Asian summer and winter monsoons play a major role in the global energy transport and water cycle by redistributing the total solar energy input to the Earth. The overall goal of the GEWEX Asian Monsoon Experiment (GAME) is to understand the role of the Asian monsoon in the global climate system and develop methods for long-range forecasting.
About 60% of the population in the world live in the monsoon Asia. Water management of this area for agriculture, industry and human life is crucial for the people and the countries of this area. The potential clients of GAME is, therefore, all the people living in this territory. The hydrological and meteorological agencies are very keen to be benefited by this project, particularly for improving their skills of forecasting seasonal rainfall and water resources. Agencies for natural disaster prevention of each country are also fundamental clients of GAME, since to predict the irregular weather conditions which potentially bring about natural disasters such as flood and drought during the monsoon season is an essential task of these agencies. Farmers and agricultural communities will also be quite interested in the outcome of this project, who are mainly engaged in rice cultivation, depending on the water management in the monsoon climate.
The management structure for this program involves researchers in universities and governmental institutes and agencies of the countries in monsoon Asia. At present, eight countries (Japan, China, Thailand, Korea, Russia, Malaysia, Singapore and India) are involved in the GAME International Science Panel (GISP). GISP also has advisory members from GCIP (Dr. Allan Hall) and USA (Prof. T.C. Chen) and an observer from Hongkong (Dr. Johnny Chan.) Tetsuzo Yasunari, who is also a chairman of the Japan National Committee for GAME, tentatively chairs GISP.
Links:
http://www.britannica.com/eb/article?eu=119600
http://www.gewex.com/
http://daac.gsfc.nasa.gov/DAAC_DOCS/geomorphology/GEO_5/GEO_plate_D-11
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