西藏的水土流失特点及水土保持工作

分析了西藏地区的水土流失特点和成因,指出西藏地区的土壤侵蚀类型主要有水力侵蚀、风力侵蚀和冻融侵蚀3种类型,水蚀范围较小,约占总侵蚀面积的6%,风蚀范围更小,约占总侵蚀面积的5%,冻融侵蚀面积约占总侵蚀面积的89%,是土壤侵蚀的主要类型;土壤侵蚀类型在地域上成多样化分布,土壤侵蚀在垂直方向上呈规律分布.提出了西藏自治区的水土保持工作应遵循的原则:①必须把预防监督放在首位;②重点治理雅鲁藏布江中游的“一江两河”地区和“三江”流域地区的河谷滩地和两侧的坡地;③开展水土保持综合试点工作,以点带面,逐步推进;④注重开展水土保持科学技术研究,提高水土流失防治技术水平.最后介绍了西藏自治区的水土保持工作进展.

Water and soil loss in Tibet and measures for conservation

The characteristics and causes of water and soil loss in Tibet were analyzed. The soil erosion was divided into three types, i.e. the hydraulic erosion, the wind erosion, and the freeze-thaw erosion, which account for 6%, 5%, and 89% of the total area of soil erosion, respectively. Therefore, the freeze-thaw erosion is the main type of soil erosion. Research shows that the types of soil erosion are diversely distributed in different areas and regularly distributed in vertical direction. Some principles that should be followed in water and soil conservation in Tibet were put forward: main attentions should be paid on prevention and monitoring of water and soil loss; the emphases of water and soil conservation should be placed on the alluvial plain and sloping land in the three-river region on the middle Yarlungzangbo River and the upper reaches of the Jinsa River, the Lancang River and the Lujiang River; the comprehensive regulation should be extended from some small catchments to the whole river basin; (scientific) research should be strengthened to improve the technique for prevention of water and soil loss. Finally, some advances in water and soil conservation in the Tibet Autonomous Region were introduced.