指纹法研究花岗岩区典型崩岗小流域悬浮泥沙来源

发布时间：2018-08-28 09:18

【摘要】：为研究花岗岩区典型崩岗小流域内悬浮泥沙来源,以安溪县龙门镇崩岗侵蚀小流域为研究对象,在4种土地利用类型(侵蚀林地、茶园、耕地和崩岗侵蚀区)中共采集85个泥沙源地土样,同时在河道布设采样器收集降雨后侵蚀悬浮泥沙。通过分析样品中的34种指纹因子,运用复合指纹法筛选出最佳指纹因子组合,并计算出各泥沙源地的泥沙运移规律。结果表明:不同泥沙源地悬浮泥沙中同种指纹因子存在显著差异,利用Kruskal-Wallis检验和多元判别筛选出Ca、Li、Sn、K和Ba为最佳指纹因子组合(累积贡献率大于90%);同时利用多元混合模型得出茶园的悬浮泥沙相对贡献百分比为33%,耕地为27%,侵蚀林地和崩岗侵蚀区均为20%,且混合模型优度拟合检验值为0.89。进一步分析表明,降雨对崩岗侵蚀区的影响最大,茶园和崩岗侵蚀区单位面积产生悬浮泥沙量明显高于其他两个源地,说明崩岗侵蚀区和茶园是花岗岩区崩岗小流域中需要采取防治措施的重点。
[Abstract]:In order to study the source of suspended sediment in a typical gully valley in granite region, Longmen town, Anxi County, was studied in this paper. Four types of land use (eroded woodland, tea garden) were used as the research object. A total of 85 soil samples from sediment sources were collected, and a sampler was installed in the river to collect erosion suspended sediment after rainfall. Based on the analysis of 34 fingerprint factors in the samples, the best combination of fingerprint factors was selected by using the compound fingerprint method, and the sediment transport law of each sediment source was calculated. The results show that there are significant differences in homologous fingerprint factors in suspended sediment from different sediment sources. By using Kruskal-Wallis test and multivariate discriminant, Ca,Li,Sn,K and Ba were selected as the best fingerprint factors (cumulative contribution rate was more than 90%), and the relative contribution percentage of suspended sediment in tea garden was 33 3, cultivated land 27 and eroded forest land. The optimum fitting test value of mixed model is 0.89. Further analysis shows that rainfall has the greatest influence on the erosion area of collapse, and the amount of suspended sediment per unit area of tea garden and collapse erosion area is obviously higher than that of the other two sources. The results show that the erosion area and tea garden are the key points for the prevention and control measures in the small watershed of granite area.
【作者单位】：福建农林大学资源与环境学院;福建省土壤环境健康与调控重点实验室;
【基金】：福建省自然科学基金项目(2015J01156) 国家自然科学基金项目(41571272) 国家科技支撑计划项目(2014BAD15B0303)
【分类号】：S157

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