| 其他摘要 | The Qinghai-Tibet Plateau is an important ecological barrier in China, and plays an important role in maintaining
climate stability, carbon balance and water resources. It is known as the “Asian water tower” and the “regulator” of the
environment of Asia and even of the northern hemisphere. Under the background of global warming and population growth, the
Qinghai-Tibet Plateau is very sensitive to climate changes. As the Qinghai-Tibet Plateau is highly diversified in landform, its
climate is very complex. Therefore, there are many kinds of erosion forces, such as freezing-thawing, wind, water and gravity.
The existing researches made use of RS and GIS, wind tunnel simulation, runoff plot monitoring and other experimental methods
to study causes and temporal and spatial distribution of the different types of soil erosion. Some scholars also conducted
experiments on soil erosion control in some regions, and evaluated effectiveness of the measures. Findings of these researchesprovide some valuable information for studies on soil erosion in the Qinghai-Tibet Plateau. However, compared with other parts
of China, the Qinghai-Tibet Plateau is relatively new in the study on soil erosion. This paper collated and analyzed what has been
done in the research on freeze-thaw erosion, wind erosion, water erosion and gravity erosion in the Qinghai-Tibet Plateau, and
found out some issues that call for attention. Firstly, divergence exists in definition of freeze-thaw erosion: e.g. freeze-thaw
erosion should encompass the factors of wind, water, and gravity, or not? Secondly, geological erosion is confused with soil
erosion in concept. Thicker humus layers are found in chestnut soil and mountain shrub soil in the Qinghai-Tibet Plateau except
for in Huangshui Valley, Qinghai Lake basin, Hefei Long Qu Valley and Lhasa River Valley, and the two types of soils are
relatively mature. However, soils in the other areas contain many coarse gravels or gravels. Geological erosion is a natural process
that carries not only includes soil particles, but also rocks and weathered rocks from slopes and banks. So, in the Qinghai-Tibet
Plateau where gravels dominate in the surface layer, what happens more, soil erosion or geological erosion? And thirdly, the topic
of soil erosion still lacks basic research. For example, temperature and soil moisture data are the basis for the study of freeze-thaw
erosion, however, at present, changes in soil temperature are generally reflected by air temperature data, and soil moisture data of
a large area are derived from remote sensing data, and measured data in field are very limited. Consequently, the model for
evaluating freeze-thaw erosion is not very accurate; Runoff and sediment monitoring data are important information for exploring
law of the water erosion on slopes at a watershed scale, however, besides the measured data of the areas of the Qinghai-Tibet
Highway slope and Three-river Source, of other areas very limited data are available; and soil and vegetation data are the basic
ones needed for evaluation of regional erosion, but little is measured. In the future, the study in this area should dedicate more
effort to basic work, such as soil erosion monitoring, pay more attention to influence of changes in temperature on soil erosion,
and attach more importance to prevention and control of soil erosion, so as to provide certain scientific basis for decision-making
to protect the ecological barrier in China. |
修改评论