张君茹+岳大鹏+达兴+程金文+贺燕子

摘要：对延河4个子流域1982—2010年的产沙量、降雨量采用Mann-Kendall非参数检验法、累积距平法分析其变化趋势及产沙量突变点，分析汛期和全年产沙量与径流量的关系，使用水文分析法分离了人类活动和气候变化对流域产沙量的影响，最终结合景观指数阐述植被与泥沙的关系。结果表明：①该流域产沙比较集中，主要在6—9月份。研究时段内研究区的产沙量显著下降（P<0.01），降雨量也呈下降趋势，并且不同子流域产沙量突变时间不一致，主要集中在1996年。②人类活动对4个子流域产沙量的变化起主导作用，甘谷驿人类活动所占比重最小仍达到69%。③延河各子流域水土流失得到缓解主要是由于草地以及森林面积增加的同时对应破碎度降低、农田面积减少的同时对应破碎度降低。

关键词：延河流域；产沙量变化；Mann-Kendall累积距平法；水文分析法；景观格局指数

中图分类号：S157.1文献标识号：A文章编号：1001-4942（2017）03-0106-07

AbstractThe sediment yield and rainfall of 4 sub-basins of the Yanhe River Basin from 1981 to 2010 were studied with Mann-Kendall nonparametric tests and cumulative departure method to investigate the change trend and sediment yield mutation point， and the relationship of flood season and annual sediment yield with the runoff volume were analyzed. Then the impacts of human activities and climate change on sediment yield were studied using the hydrological analysis method. Finally， the relationship between vegetation and sediment yield was expounded combining landscape index. The results showed that the sediment yield in the basin was relatively concentrated， which mainly appeared between June and September. The sediment yield showed a significant downward trend （P<0.01） during the research period， and the rainfall presented a non-significant downward trend. The sediment yield mutation points were different in different sub-basins， which mainly concentrated in 1996. Human activities played a leading role on the change of sediment yield in 4 sub-basins. In Ganguyi， the influence proportion of human activity was the minimum， which was still 69%. The release of the waterhe loss and soil erosion in sub-basins of the Yanhe River Basin was mainly due to the increase of grassland and forest area and the lower of fragmentation at the same time， and also the reduce of farmland area and the lower of fragmentation.

KeywordsThe Yanhe River Basin；Change of sediment yield；Mann-Kendall； Cumulative departure method；Hydrologic analysis；Landscape pattern index

近年来，受气候变化和人类活动的共同影响，河川流量与产沙量发生了显著变化，从而直接对流域水资源的配置、开发与利用产生影响[1，2]。目前，许多河流受自然因素（主要是降雨）及人类活动（如水坝建设、调水、采沙、植被修复等）影响，流量和产沙量發生了显著变化[3-5]。因此，自然要素变化和人类活动影响下的水沙变化已成为水科学研究的热点问题之一。

延河流域位于黄土高原水土流失较严重的区域，长期以来由于土地利用不合理，滥垦、滥伐、滥牧，导致水土流失加剧，农业自然资源遭到严重破坏，以至造成生态经济系统失调，水旱灾害频发，给当地群众生产生活带来严重威胁[5-7]。因此，迫切需要掌握该流域泥沙变化的规律及变化机制，以期为该流域的水资源管理提供科学依据。

如何定量区分人类活动与气候变化对流域产沙量的影响已成为研究者关注的重点，并取得一定成果[8-10]。……