北川震后滑坡体表层土壤颗粒组成及团聚体空间变化特征  

Spatial Variability of Post-shock Surface Soil Aggregates and Particle Composition in the Landslide Area of Beichuan County, South-western China

作　　者：麦积山 郑江坤[1] 赵廷宁[3] 史常青[3] 王文武[1] MAI Jishan;ZHENG Jiangkun;ZHAO Tingning;SHI Changqing;WANG Wenwu(Key Laboratory of Soil and Water Conservation&Desertification Combating of Sichuan Provincial Colleges and Universities,College of Forestry,Sichuan Agricultural University,Chengdu 611130,China;Water Conservancy and Hydropower Engineering Design Co.,Ltd.of Shuyu in Sichuan Province,Chengdu 610072,China;School of Soil and Water Conservation,Beijing Forestry University,Beijing 100086,China)

机构地区：[1]四川农业大学林学院四川省高校水土保持与荒漠化防治重点实验室,成都611130 [2]四川蜀禹水利水电工程设计有限公司,成都610072 [3]北京林业大学水土保持学院,北京100086

出　　处：《山地学报》2019年第1期30-40,共11页Mountain Research

基　　金：国家自然科学基金项目( 41601028;41671277); 国家林业局公益性行业科研专项经费项目( 201104109); 中国博士后科学基金面上项目( 2012M511938)~~

摘　　要：滑坡作为西南地区常见的地质灾害,对坡面土壤结构和植被扰动极大。本文以北川擂鼓镇凤凰山震后滑坡体表层土壤为研究对象,选取滑坡区(Ⅰ)、过渡区(Ⅱ)和未破坏区(Ⅲ) 3个样地,结合网格取样和室内分析,运用地统计学和经典统计学方法对其颗粒组成和土壤团聚体特征进行分析。结果表明:(1) 3样地的土壤颗粒组成均以砂粒为主,显著大于黏粒和粉粒。土壤颗粒组成分形维数与砂粒含量呈极显著性负相关,与黏粒和粉粒含量均呈极显著性正相关。(2)Ⅰ样地中>5 mm的风干性团聚体含量最低,Ⅲ最高。3样地的土壤水稳性团聚体均以>2 mm的粒径为主,总体上呈现出团聚体数量随粒径的减小而减小的趋势。风干和水稳性土壤团聚体的平均重量直径(MWD)和几何平均直径(GMD)值均表现为Ⅰ样地<Ⅱ样地<Ⅲ样地,风干性团聚体分形维数表现为Ⅰ样地≈Ⅱ样地>Ⅲ样地,水稳性团聚体分形维数表现为Ⅰ样地>Ⅱ样地>Ⅲ样地。(3)风干和水稳性团聚体稳定性参数和土壤颗粒组成的半方差函数理论模型拟合程度均较好。除水稳性土壤团聚体MWD表现为中等强度空间自相关外,其他团聚体稳定性参数均表现为强烈空间自相关性;黏粒表现为中等空间自相关性,粉粒和砂粒表现为强烈的空间自相关。(4)风干和水稳性土壤团聚体MWD和GMD值从Ⅰ样地至Ⅲ样地大致呈逐渐增加趋势,而土壤团聚体分形维数则呈相反分布规律;土壤颗粒组成从Ⅰ样地至Ⅲ样地呈砂粒含量逐渐减少而黏粒含量逐渐增加的规律。综上,滑坡体表层黏粒土壤大量流失后,表层土壤沙砾化,土壤团聚体的稳定性降低,表现出较强的结构性空间自相关。After May 12 Wenchuan earthquake,a large number of geological hazards appeared such as landslides and collapses.As a common geological hazard,landslides seriously destructed mountain vegetation and soil structure.In the landslide of Fenghuang Mountain in the Leigu town,Beichuan County,landslide area (Ⅰ),transition area (Ⅱ) and non-damaged area (Ⅲ) were selected as the research plots.Combined with the grid sampling,laboratory analysis,Geo-statistics,and classical statistics methods,the characteristics of soil physical properties were studied.The results showed that sand contents was the dominant fraction of soil in three plots which was significant higher than that of clay and silt.The fractal dimension of soil particle composition had high negative correlation with sand content.However,it had high positive correlation with clay and slit contents.The soil dry aggregates content in plotⅠand plot Ⅲ were the lowest and highest among three plots whose diameter were more than 5 mm,respectively.Meanwhile,soil water stable aggregates accounted for the largest proportion whose diameter was more than 2 mm.Furthermore,soil water stable aggregate contents generally decreased with the decrease of aggregate diameter size.The values of Mean Weight Diameter (MWD) and Geometric Mean Diameter (GMD) were the biggest in plot Ⅲ,followed by plotⅡand plotⅠfor soil water stability aggregates and soil dry aggregates.The fractal dimensions of soil dry aggregate almost were equal between plotⅠ and plot Ⅱ which are bigger than that of plot Ⅲ.Nevertheless,the fractal dimension of soil water stability aggregates was biggest in plotⅠ,followed by plot Ⅱand plot Ⅲ.The semi-variance model of soil aggregates stability parameters and soil particle composition had a higher fitting degree.The block ratio of clay particle and the MWD of soil water stability aggregates were 45.9% and 65.3%,respectively,With the exception of MWD as moderate spatial autocorrelation.Soil aggregate parameters and soil particles showed highly spa

关 键 词：“5.12”汶川地震 滑坡体 土壤团聚体 土壤颗粒组成 空间分布 

分 类 号：S153.6[农业科学—土壤学]