Permafrost

Key words: global warming; upper Yellow River; runoff variation; circumfluence
Influence of alpine meadow land cover change on runoff precipitation of
the Qinghai-Tibet Plain, China
Yuanshou Li 1 , Genxu Wang 1,2 , Qingbai Wu 1
(1.Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences,
Lanzhou 730000; Email: yshli@lzb.ac.cn ; 2. Institute of Mountain Hazard and Environment, Chinese
Academy of Sciences & Ministry of Water Conservancy, Chengdu 610041)
Abstract: There are many permafrost and alpine meadows covers in the Beiluhe basin within
Fenghuo Mountain area of Qinghai-Tibet Plain. The small Zuomaoxikongqu River in the
Fenghuo Mountain area, where vegetation is simple and dominated by alpine cold meadows
and alpine steppe meadows, are selected as typical catchments to study contrastively the
impacts of alpine meadow land cover change on rainfall-runoff processes and soil erosion. The
relationship between frozen soil together with its precipitation-runoff process and vegetation
growing environment is discussed according to the monitored data of precipitation-runoff on
active layers in the Tibet Plateau. The precipitation-runoff process in slop land is compared with
that in permafrost. Influence of alpine meadow land cover change on rainfall-runoff discussed.
Analysis result shows that vegetation ecology vegetation ecology in cold region has an
interactive relationship with alpine meadow land cover change and its rainfall-runoff process.
Vegetation land cover change and its rainfall-runoff process not only control the change of Surface
state, but also affect the vegetation-growing extent. The result indicates that on the 30º slope in
alpine meadow and under the same condition of precipitation, the runoff in the meadow which
holds 30% land-cover is apparently more than that in the meadows which hold 92% and 68%
land-cover; at the same time, sediment yield is also more than that of the later two, and the
average amount of sediment per precipitation is twice to four times as that of them. The
corroding amount in the earth's surface is 3-10 times of the last two kinds of situations on
average to arise from this. Cover degree high two place is it miscarry sand result is it find to
compare with to produce relatively, under the same precipitation terms, 92% high to overlay
place of degree runoff that produce overlay flow heavy foot-path producing in the place of
degree than 68%, sand yield is just opposite. The results support the concept of vegetation as a
major control upon runoff and sediment production.
Key words: alpine meadow, land cover change, precipitation-runoff, Qinghai-Tibet Plain
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