Song Chunlin, Wang Genxu, Sun Xiangyang, Chang Ruiying, Mao Tianxu
Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Sci Rep. 2016 May 11;6:25963. doi: 10.1038/srep25963.
Under the context of dramatic human disturbances on river system, the processes that control the transport of water, sediment, and carbon from river basins to coastal seas are not completely understood. Here we performed a quantitative synthesis for 121 sites across China to find control factors of annual river exports (Rc: runoff coefficient; TSSC: total suspended sediment concentration; TSSL: total suspended sediment loads; TOCL: total organic carbon loads) at different spatial scales. The results indicated that human activities such as dam construction and vegetation restoration might have a greater influence than climate on the transport of river sediment and carbon, although climate was a major driver of Rc. Multiple spatial scale analyses indicated that Rc increased from the small to medium scale by 20% and then decreased at the sizable scale by 20%. TSSC decreased from the small to sizeable scale but increase from the sizeable to large scales; however, TSSL significantly decreased from small (768 g·m(-2)·a(-1)) to medium spatial scale basins (258 g·m(-2)·a(-1)), and TOCL decreased from the medium to large scale. Our results will improve the understanding of water, sediment and carbon transport processes and contribute better water and land resources management strategies from different spatial scales.
在河流系统遭受剧烈人类干扰的背景下，控制从流域到沿海海域的水、沉积物和碳输送的过程尚未完全被理解。在此，我们对中国121个站点进行了定量综合分析，以找出不同空间尺度下河流年输出量（Rc：径流系数；TSSC：总悬浮泥沙浓度；TSSL：总悬浮泥沙负荷；TOCL：总有机碳负荷）的控制因素。结果表明，尽管气候是Rc的主要驱动因素，但诸如大坝建设和植被恢复等人类活动对河流泥沙和碳的输送可能比气候具有更大的影响。多空间尺度分析表明，Rc从中等空间尺度到小尺度增加了20%，然后在大尺度上下降了20%。TSSC从小尺度到中等尺度下降，但从中等尺度到小尺度增加；然而，TSSL从小尺度（768 g·m(-2)·a(-1)）到中等空间尺度流域（258 g·m(-2)·a(-1)）显著下降，而TOCL从中等尺度到小尺度下降。我们的结果将增进对水、泥沙和碳输送过程的理解，并有助于制定不同空间尺度下更好的水资源和土地资源管理策略。
