黄土高原典型切沟土壤水分时空分布特征及其影响因素  

Characteristics and Influencing Factors of Spatiotemporal Distribution of Soil Moisture in Typical Gully of the Loess Plateau

作　　者：陈明玉 邵明安[1,2,4,5] 李同川 贾玉华 甘淼[1] CHEN Mingyu;SHAO Ming’an;LI Tongchuan;JIA Yuhua;GAN Miao(College of Resources and Environment,Northwest A&F University,Yangling,Shaanxi 712100,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences,Yangling,Shaanxi 712100,China;College of Water Conservancy,Shenyang Agricultural University,Shenyang 110866,China;Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]中国科学院水利部水土保持研究所,陕西杨凌712100 [3]沈阳农业大学水利学院,沈阳110866 [4]中国科学院地理科学与资源研究所,北京100101 [5]中国科学院大学资源与环境学院,北京100190

出　　处：《土壤学报》2021年第2期381-390,共10页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(41571221,41807011)资助。

摘　　要：研究切沟土壤水分及干层时空分布特征,有利于提高地区水资源利用效率及植被恢复效益。以神木市六道沟小流域典型切沟为研究对象,对土壤水分状况进行定位监测,分析沟底、沟缘和沟岸土壤水分时空分布、干层分布特征及其影响因素。结果表明:沟底土壤含水率由沟头至沟口呈明显增加趋势。沟底、沟缘和沟岸0~480 cm剖面土层平均含水率分别为17.1%、13.5%和14.4%。沟底0~480 cm剖面土层平均储水量为80.54 cm,沟缘及沟岸分别为67.49 cm和71.05 cm。地形和土壤质地是影响土壤储水量的主要因素;土壤储水量与距沟头距离、土壤黏粒、粉粒含量呈极显著正相关。沟底、沟缘和沟岸均有干层出现,且主要集中在靠近沟头位置,平均厚度和起始深度分别为243 cm和257 cm,平均含水率为9.5%。沟底、沟缘和沟岸干层平均厚度分别为100 cm、286 cm和331 cm。研究结果可为该区域土壤水资源管理和土壤水库评价提供理论依据。【Objective】Although large-scale afforestation improves vegetation coverage of the Loess Plateau,it also leads to soil moisture deficit in this region.The emergence of dry soil layers slows down or cuts off the exchange of soil moisture between the upper and lower layers,thus causing deterioration of the soil environment and degradation of the vegetation.As an important part of the slope-gully system on the Loess Plateau,the development and evolution of gullies change the soil moisture on the slope,and the distribution and utilization efficiency of water resources in the catchments.However,so far little has been done on temporal and spatial distribution of soil moisture in gully and its surrounding areas.【Method】In this study,a typical gully in Liudaogou Watershed of Shenmu County was selected as the research object for monitoring soil moisture.In the gully three sample strips were laid out at the bottom(along the centerline),the edge(1 m wide)and the gully bank(20 m wide).Following the direction of the gully,12 observation points were arranged at the gully bottom from the head to the outlet of the gully,and 7 observation points were set up along the gully edge and bank,separately.At each point,a hole was prepared with an auger to the depth of about 480 cm at the bottom section,and approximately 980 cm at the edge and bank sections for insertion of a neutron tube(CNC503DR)for in-situ observation of soil moisture.Measurement was made at 10 cm intervals along the 0—100 cm soil profile,and at 20 cm intervals when it got below 100 cm.Then soil moisture distribution was characterized and dried soil layers were analyzed and compared,as well as its influencing factors.Soil samples were collected while holes were prepared.【Result】(1)Soil moisture conditions were better at the bottom than at the edge and the bank,and water deficit was the most obvious at the edge.At the bottom section,soil moisture content increased obviously along the gully from the head to the outlet,and higher in the deep layers than in th

关 键 词：切沟 土壤干层 土壤储水量 水分分布 黄土高原 

分 类 号：S152.7[农业科学—土壤学]