黄土高原多沙粗沙区泥沙集中度变化特征及驱动因素

目的]揭示黄土高原多沙粗沙区的泥沙和泥沙集中度的变化规律，阐明泥沙集中度的影响因素，进而为流域水土流失治理和生态保护提供一定的科学依据。方法]基于1956—2010年皇甫川、孤山川、秃尾河、窟野河和无定河流域的输沙量数据，利用Mann-Kendall趋势检验法、Pettitt突变点检验法、Morlet小波分析方法分析了黄土高原多沙粗沙区泥沙集中度的时空变化特征，通过Pearson相关系数探究了泥沙集中度与生态建设措施的相关性。结果](1) 1956—2010年，黄土高原多沙粗沙区的输沙量呈现显著减少的趋势，但是皇甫川、孤山川、无定河流域的泥沙集中度呈现显著增加的趋势。(2)孤山川与无定河流域的泥沙集中度具有显著的(p<0.05)突变点，分别为1990年与1986年。(3)研究区泥沙集中度主周期介于15～55 a。(4)径流集中度对于研究区泥沙集中度有显著的影响。除此之外，生态建设措施面积与泥沙集中度有显著的正相关关系，其中梯田、造林和种草对于研究区的泥沙集中度的影响程度最大。结论]黄土高原多沙粗沙区的输沙量逐渐减少且越来越集中，泥沙集中度受到降雨径流和生态建设措施等因素影...

Variation Characteristics and Driving Factors of Sediment Concentration in Sandy Region of the Loess Plateau

Objective] The aim of this study is to reveal the variation law of sediment and sediment concentration in the Loess Plateau, clarify the influencing factors on sediment concentration, and provide some scientific bases for soil erosion control and ecological protection in the basin. Methods] Based on the sediment transport data of Huangfuchuan, Gushanchuan, Tuwei, Kuye and Wuding River basins from 1956 to 2010, the temporal and spatial variation characteristics of sediment concentration in the coarse sediment region were analyzed by using Mann-Kendall trend test, Pettitt change point test and Morlet wavelet analysis. The correlation between sediment concentration and ecological construction measures was explored by Pearson correlation coefficient. Results](1)From 1956 to 2010, the sediment transports in the study area showed significant decreasing trends, but the sediment concentrations in the Huangfuchuan, Gushanchuan and Wuding river basins showed significant increasing trends.(2)The sediment concentration in Gushanchuan and Wuding River basins had significant abrupt change(p<0.05)in the years of 1990 and 1986, respectively.(3)The main cycle of sediment concentration in the study area was 15～55 years.(4)Runoff concentration had a great impact on sediment concentration in the study area. In addition, the area of ecological construction measures had a significant positive correlation with sediment concentration, and terrace, afforestation and grass planting had the greatest influence on sediment concentration in the study area. Conclusion] In the Loess Plateau, the amount of sediment is gradually reduced and more and more concentrated. The concentration of sediment is affected by rainfall runoff and ecological construction measures.