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以黄土高原为例,从坡面和小流域土地利用与土壤侵蚀、土地利用和景观工程对径流变化的影响、土地利用和景观工程对泥沙变化的影响、土地可持续利用综合评价等方面来揭示土地利用和景观工程的水土保持效应。研究表明:黄土高原区域产水和侵蚀都显著减少,这是长期政策调整和区域转型发展的结果,坝库、梯田等工程措施是70年代至90年代黄土高原产沙减少的主要原因,占54%。实施退耕还林政策以来,黄土高原成为黄河流域植被恢复最显著区域,平均植被覆盖率从1978年25%增加至1998年29%,2010年达到46%。2000年以来林草植被措施成为土壤保持的主要贡献者,占57%。黄土高原地区土地利用变化与土壤保持、碳固定具有正效应,与产水量具有负效应,生态系统服务之间的消长和权衡具有尺度依赖性,植被恢复需要与区域环境条件和水分的生态承载力相适应、特别是随着坝库等工程措施拦沙能力的逐渐下降,维持一个可持续的植被生态系统对输沙量具有更加重要的作用。因此,黄河水沙管理需要从黄土高原小流域综合治理转向全流域整体协调。
Taking the Loess Plateau as an example, from the aspects of land use and soil erosion in slope and small watershed, impact of land use and landscape engineering on runoff change, impact of land use and landscape engineering on sediment change and comprehensive evaluation of sustainable land use Reveal the effect of soil and water conservation of land use and landscape engineering. The results show that both water production and erosion in the Loess Plateau decreased significantly, which is the result of long-term policy adjustment and regional transformation and development. Engineering measures such as dams and terraces were the main reasons for the decrease of sediment yield in the Loess Plateau from 1970s to 1990s %. Since the implementation of the policy of returning farmland to forests, the Loess Plateau has become the most prominent area for vegetation restoration in the Yellow River Basin. The average vegetation coverage rate increased from 25% in 1978 to 29% in 1998 and reached 46% in 2010. Forest and grass vegetation measures have been the main contributor to soil conservation since 2000, accounting for 57%. Land use change in the Loess Plateau has a positive effect on soil conservation and carbon fixation, which has a negative effect on water production. Scale growth and tradeoffs between ecosystem services are scale dependent, and the need for vegetation restoration is related to regional environmental conditions and ecological carrying capacity of water In particular, with the gradual decline of the silt-holding capacity of dams and other engineering measures, maintaining a sustainable vegetation ecosystem plays a more important role in sediment discharge. Therefore, the Yellow River water and sediment management needs to shift from the comprehensive management of small watersheds in the Loess Plateau to the overall coordination of the whole basin.