...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Science in China. Series D, Earth sciences >The impact of vegetation restoration on erosion-induced sediment yield in the middle Yellow River and management prospect
【24h】

The impact of vegetation restoration on erosion-induced sediment yield in the middle Yellow River and management prospect

机译：黄河中游植被恢复对侵蚀产沙的影响及治理前景

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

According to the characteristics of water and erosion environments of different natural zones on the Loess Plateau, this paper studies changes of vegetation types, distribution boundaries of forest and grass as well as restoration capacity of vegetation in different natural zones in the middle Yellow River. The annual precipitation of 530 mm is the critical annual precipitation for forest and grass distribution in the middle Yellow River. Among the zonal and azonal environmental factors affecting watershed sediment yield, the intermediate diameter D_(50) (mm) of suspended load and forest coverage (V, %) play the leading role. Of them the effect weight of forest coverage (V, %) on catchments sediment yield is only 3.4% less than the role of the intermediate diameter (D_(50), mm), they are almost the same. To effectively control soil erosion in semiarid, especially in hilly-gullied areas and make sediment transport modulus reduce to less than 6000 t/km~2, it is rather difficult by merely relying on natural restoration of forest. In the process of cultivated land conversion into forest land and grassland, measures suiting local conditions should be adopted in tree species selection and artificial afforestation (grass planting) based on management with biological measures for slopeland and engineering measures for hilly-gullied areas, so that watershed forest coverage in key counties can reach at least over 30%. Compared with the standard period of precipitation prior to the 1960s, with the decrease of annual precipitation at various periods, plant productivities decline to different degrees under natural conditions. The main reason accountable for the low survival rate of new seedlings and grass over years is due to precipitation decrease. In light with regression models of annual precipitation and natural vegetation productivities, it is possible to obtain estimated values of watershed natural vegetation productivity and eco-water consumption needed for the restoration to the standard period respectively for the present time or arbitrary period since the 1970s, thus providing a scientific basis for forest and grassland restoration in the middle Yellow River and the management prospect.
机译：根据黄土高原不同自然区水土流失特征，研究黄河中游不同自然区植被类型变化，林草分布边界以及植被恢复能力。 530毫米的年降水量是黄河中游森林和草类分布的关键年降水量。在影响流域沉积物产量的地带和地带环境因素中，悬浮负荷的中间直径D_（50）（mm）和森林覆盖率（V，％）起主导作用。其中，森林覆盖率对流域沉积物产量的影响权重（V，％）仅比中间直径（D_（50），mm）的作用小3.4％，它们几乎相同。为了有效地控制半干旱地区的土壤侵蚀，特别是在丘陵沟壑区，并使沉积物的输送模量降低到小于6000 t / km〜2，仅依靠森林的自然恢复是相当困难的。在耕地退耕还林的过程中，应结合对坡地生物措施的管理和对丘陵沟壑区的工程措施的管理，在树种选择和人工造林（草木种植）中采取适合当地条件的措施，以便重点县的流域森林覆盖率至少可以达到30％以上。与1960年代之前的标准降水期相比，随着不同时期年降水量的减少，自然条件下植物的生产力有不同程度的下降。造成多年新苗和草成活率低的主要原因是降水减少。根据年降水量和自然植被生产力的回归模型，有可能分别获得当前或1970年代以来任意时期恢复到标准时期所需的流域自然植被生产力和生态耗水量的估计值，从而为黄河中游的森林和草地恢复提供科学依据和管理前景。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号