黄河流域土壤侵蚀在不同尺度的表现(摘要)

冉启华，叶盛

(浙江大学水利工程系，浙江　杭州　310058)

【摘　要】　土壤侵蚀和泥沙运动在陆地地貌演化和营养物质以及污染物的生物地化循环过程中起到了重要的作用。由于流域内严重的水土流失问题，黄河流域一直是研究的焦点。近年来，各种水土保持措施已经取得了显著的成果，但是不同措施所起到的作用仍有争议。在这里我们对流域内八个主要支流上水文站的径流和泥沙数据进行了分析。这些水文站覆盖了不同的集水面积，气候，地形地貌特征以及人类活动程度。研究表明泥沙浓度随着径流的增加而减小。此外，泥沙和径流的相关性变得越来越小，这种不相关性在不同的时间尺度上都存在。另外，我们的分析发现，尽管黄土高原内的不同区域的气候和地貌的差异可能较大，土壤侵蚀和泥沙输移与植被有较强的相关性。植被在水土保持上起到的作用和它与气候以及地形地貌在共同演进的过程中形成的相关性，使得植被可以被用来揭示黄河流域泥沙过程，并可为正在进行的退耕还林等生态修复提供参考和指示。

【关键词】　黄河流域；侵蚀；不同尺度

Characteristics of Erosion in the Huanghe River Basin Across Scales

RAN Qihua,YE Sheng

(Dept.of Hydraulic Engineering,Zhejiang University,Hangzhou Zhejiang Province　310058)

Abstract:Sediment erosion and transport play important roles in terrestrial landscape evolution and biogeochemical cycles of nutrients and contaminants.Known for the severe sediment erosion problem in the Huanghe River Basin,considerable achievement in sediment reduction has been achieved in recent years,but the effectiveness of the various approaches is still under debate.Here we analyze the sediment and discharge data from gauges at 8 major tributaries within the Huanghe River Basin,covering a range of catchment sizes,climate,topographic characteristics and degree of human intervention.Our results show that sediment concentration declines steadily with discharge across scales.More than that,the coupling between sediment and discharge was also observed declining at various temporal scales for our study catchments.On the other hand,our analysis suggests that sediment erosion and transport has strong correlation with vegetation despite heterogeneity in climate and landscape.The resistance to erosion offered by vegetation,and its strong co-variation with climate and topographic characteristics in the Huanghe River Basin makes vegetation a reliable indicator of sediment transport,and can thus provide guidance for ongoing ecosystem restoration schemes(i.e.the Grain-for-Green project).

Key words:Huanghe River Basin;Erosion;Scales