西北黄土区水土流失现状与综合治理对策

Current status and comprehensive control strategies of soil erosion for loess region in the Northwestern China

通过西北黄土区水土流失与生态安全综合考察，在对该区水土流失现状特点与发展趋势综合分析的基础上，总结水土流失治理的主要经验，提出水土保持与综合治理的目标和对策。根据遥感分析，黄土高原地区2000年土壤侵蚀面积41．9万km^2，占总面积的67．14％，其中水力侵蚀占总面积的52．78％，风力侵蚀占总面积的14．11％。近年来，黄土高原地区土壤侵蚀强度及其面积发生显著变化，强度侵蚀面积显著减少；目前黄土高原地区水土保持措施平均每年可减少入黄泥沙4．1亿-4．5亿t。该区综合治理对策是：以生态安全和经济可持续发展为目标，实现生态、经济及社会效益协调发展；以黄土丘陵区与风沙丘陵区为主，以粗泥沙集中来源区为重点；进一步扩大生态修复规模，加快林草植被建设；加大淤地坝建设力度，加快实施坡改梯工程；加强水土保持科学与技术研究，为治理工程提供有效的科技支撑，建立稳定的投入机制，加大投入力度。

Loess region in the Northwest of China is famous as its serious soil erosion and ecosystem degradation, This paper, based on the integrated survey on soil erosion and ecological security of the loess region in the Northwest of China, the current situation of soil erosion and its characteristics as well as management experience was analyzed and the strategy and countermeasures also suggested. The erosion area of loess region is about 0.419 million km^2, taking 67.14% of total area including water erosion of 52.78% and wind erosion of 14. 11%by the remote sensing survey in 2000. From 1986 to 2000, the total erosion area has increased of 5 300 km^2 dominated by the water erosion, however, the erosion area decreased of 28 400 km^2 in 2002. The survey found that the significant changes has been happened in soil erosion and distribution with the decline of strong erosion area. The soil conservation practices in loess region can contribute the reducing of sediment discharge of 0.41 billion - 0.45 billion tons per year to Yellow River. It＇s suggested that the strategy of soil con- servation on the Loess Plateau is to control the soil erosion for ecological security and economical sustainable development. The main part of erosion control on the Loess Plateau is loess hilly and gully region with the key area of coarse sand resource site; It＇s necessary to expand the area of ecosystem natural rehabilitation promoting the vegetation restoration and establish the sediment warping dam in the gully and build the terrace on the slope land; and to organize further research on soil conservation science and technique research to provide the support for conservation practice.