黄土区坡沟系统容重、饱和导水率和土壤含水量变化分析  

Variation of Soil Bulk Density,Saturated Hydraulic Conductivity and Soil Moisture Content in a Slope-gully Unit on the Northern Loess Plateau

作　　者：甘淼 贾玉华[1,2] 李同川 毛娜 赵明阳 GAN Miao;JIA Yu-hua;LI Tong-chuan;MAO Na;ZHAO Ming-yang(College of Water Conservancy, Shenyang Agricultural University, Shenyang 110866, Liaoning, China;Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences ,Beijing 100101, China;College of Resources and Environment, Northwest A＆F University, Yangling 712100, Shaanxi, China)

机构地区：[1]沈阳农业大学水利学院,辽宁沈阳110866 [2]中国科学院地理科学与资源研究所,北京100101 [3]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《干旱区研究》2018年第2期315-324,共10页Arid Zone Research

基　　金：国家自然科学基金资助项目(41571221);中国博士后科学基金资助项目(2015T80129)

摘　　要：切沟是黄土高原侵蚀沟的重要类型之一,对流域水文、植被、地貌和生态等地表过程具有深刻影响。为明确土壤物理参数对切沟地形、坡位和深度的响应,在陕北黄土高原选择典型切沟,根据其走向设置沟道、沟缘及坡面3条样线,对40个样点按照10 cm深度间隔采集0~30 cm各土层原状土样,利用定水头法和烘干法对土壤容重、饱和导水率和土壤含水量进行测定并分析。结果表明：（1）地形对容重、饱和导水率和土壤含水量具有显著或极显著影响,3个参数随坡位自下而上均呈波浪式变化趋势;沟缘和坡面位置容重随坡位上升总体呈微弱减小趋势,沟缘表层坡下土壤含水量较其他坡位明显偏低;（2）沟缘和坡面位置不同土层深度饱和导水率及容重的大小变化规律与沟道恰好相反;（3）对于各土层深度而言,沟缘和坡面土壤含水量均与沟道内差异显著,且沟缘土壤含水量总是低于坡面。以上结果表明,切沟分布改变了土壤容重、饱和导水率和土壤含水量在坡面的空间格局,在黄土区坡沟系统内不同地形条件对相关土壤物理参数的影响不应忽视。Gully is an important kind of erosional landform in watershed on the northern Loess Plateau and has a profound effect on the surface processes,such as the hydrological,vegetational,geomorphologic and ecological processes. In order to clarify the response of three soil physical parameters（ soil bulk density BD,saturated hydraulic conductivity Ks and soil moisture content SMC） to the gully topographical conditions,slope position and soil depth,in this study three sampling transects at the bottom,edge and nearby bank of an erosional gully were designed,and 40 sampling sites were designed. At every site,the undisturbed soil cores were sampled at three soil layers： 0-10 cm,10-20 cm and 20-30 cm,and they were regarded as surface,sub-surface and shallow soil layers respectively. The data of BD,Ks and SMC were obtained using the constant water-head method and oven-drying method. The results are as follows：（1） Topographical conditions significantly or highly significantly affected the values of BD,Ks and SMC,and these three parameters fluctuated in a wave-like trend along the slope length. The BD values at the gully edge and bank were decreased slightly with the increase of slope length. Except the soil surface on the gully edge,the SMC on the downslope was significantly higher than that at the middle and upper slope;（2）On the gully edge and bank,the variation trend of Ks and BD at different soil layers was opposite to that at the gully bottom;（3） At every soil-depth layer,SMCs on the gully edge and bank were significantly different from those at the gully bottom,and they were always lower on the gully edge than those on the gully bank. The results mentioned above indicated that the spatial pattern of BD,Ks and SMC on the slope were changed with the distribution of gully,and the influence of specific topographical conditions of the slope-gully unit on the soil physical parameters could not be neglected.

关 键 词：切沟 土壤容重 饱和导水率 土壤含水量 黄土高原 

分 类 号：S152[农业科学—土壤学]