【作者】 张德斌；

【导师】 黄炎和；

【作者基本信息】 福建农林大学 ， 土壤学， 2010， 硕士

【摘要】 在南方花岗岩区崩岗侵蚀严重地区安溪县龙门镇选取典型的崩岗,以崩岗不同土层红土层、砂土层和碎屑层作为研究对象,展开对崩岗不同土层抗蚀性的评价研究。最初选取由物理指标、化学指标、力学指标和综合指标组成的17个抗蚀性因子进行分析,用变异系数法将变异系数小于10%的指标剔除后,得到有机质含量、ba值、粘粒率、微团聚体含量、团聚度、结构系数、初渗速率、稳渗速率、抗剪强度和侵蚀率等10个具有代表性的指标。用聚类分析将这些指标进行分类,用模糊综合评价法求算出不同类别抗蚀性指标的评价得分。然后用模糊综合评价法评价整体指标的抗蚀性,来验证聚类分析的可靠性。最后得出崩岗不同土层抗蚀性的综合评价结果,找出了表征抗蚀性的最佳指标。用聚类分析的方法将指标分为三类:第Ⅰ类(质地渗透组):有机质、稳渗速率、初渗速率、ba值、粘粒率第Ⅱ类(团聚结构组):微团聚体总量、结构系数、团聚度、侵蚀率第Ⅲ类(力学性质组):抗剪强度对三组指标分别进行模糊数学评价。三组指标评价结果显示不同土层土壤抗蚀性强弱顺序为:抗蚀性综合得分红土层>砂土层>碎屑层。这与应用整体指标模糊综合评价得出的结果相同。因此得出结论:崩岗不同土层的抗蚀性:红土层>砂土层>碎屑层。表征花岗岩区崩岗不同土层抗蚀性的最佳指标为:侵蚀率、粘粒率、稳渗速率。由于三个指标之间的相关系数绝对值都>0.7,符合主导因子间r≥0.7的标准,因此侵蚀率、粘粒率、稳渗速率均为表示花岗岩区崩岗不同土层抗蚀性的主导因子。更多还原

【Abstract】 In the southern granite area of china, collapse gullies’erosion is very serious. Typical collapse gullies were selected in Longmen, Anxi County. We studied the soil anti-erodibility assessment factors on different soil horizons of collapse gullies. Originally, 17 factors were selected to analyse, including the physical indicators, chemical indicators, mechanical indicators and aggregative indicators.After weeding out the indicators ,whose variation coefficient was less than 10%, organic matter content, ba value, clay ratio, micro-aggregate content, degree of aggregation, structure coefficient, initial permeability rate, stable permeability rate, shear strength and erosion rate of 10 representative indicators were left. Using cluster analysis to classify these indicators, different types of the anti-erosion index scores were calculated though fuzzy synthetical evaluation method. In order to verify the reliability of cluster analysis, we proceeded to evaluate the overall indicators. Finally, we got the comprehensive evaluation result of different horizons’anti-erodibility and the best indicators to attribute the soil anti-erodibility.The indicators were classified into three clusters using cluster analysis.Cluster 1(texture and permeability cluster): organic matter content, ba value, clay ratio, initial permeability rate, stable permeability rate;Cluster 2(aggregate and structure cluster): micro-aggregate content, degree of aggregation, structure coefficient, erosion rate;Cluster 3(mechanical property cluster): shear strength.The three clusters were evaluated though fuzzy synthetical evaluation method separately. The comprehensive evaluation scores of the three horizons showed that descending order of anti-erodibility was red soil horizon, sandy soil horizon and detritus horizon. That was accorded with the evaluate result which was calculated using the overall indicators.Therefore,the conclusion is that descending order of anti-erodibility in collapse gullies is red soil horizon, sandy soil horizon and detritus horizon. The best indicators to attribute the soil anti-erodibility are erosion rate, clay ratio and stable permeability rate. The absolute values of the correlation coefficient between the each two indicators are greater than 0.7 entirely. It is in accordance with the standard that if r≥0.7,then the two indicators are all considered as the dominant factors. So erosion rate, clay ratio and stable permeability rate are the dominant factors of antierodibility of different soil horizons of collapse gullies in southern China.更多还原