摘要
该文针对70年代以来太行山前平原典型灌溉农田地下水位普遍下降的问题,通过分析中国科学院栾城农业生态系统试验站连续3 a的农田土壤水分观测资料,探讨了山前平原典型灌溉农田0~800 cm深土壤水势变化规律和0~1 540 cm深土壤水分含量变化规律。结果表明:土壤水分动态自上向下具有明显的分带性,0~800 cm土壤层水分动态可分为3层:0~200 cm为入渗-蒸发交替变动带(水分增长和消退的较快,土壤含水率变化范围为0.14~0.47 cm3/cm3,基质势变化范围为-628.21~0 cm,>200~600 cm为非稳定入渗带(土壤含水率变化范围为0.04~0.41 cm3/cm3,基质势变化范围为-311.79~0 cm,土壤水势梯度有一定变化范围在0.1~5.61 cm/cm之间),>600~800 cm为相对稳定入渗带(土壤含水率在0.03~0.35 cm3/cm3之间变化,基质势变化范围为-138.18^-45.57 cm,土壤水势梯度在单位势梯度左右浮动)。在土壤质地和土壤含水率(维持在田间持水量水平)的影响下,深层土壤层的湿润锋运动速率较快(0.13 m/d),表明地下含水层会迅速地响应地表水分输入(降水和灌溉)。结果可为太行山前平原典型灌溉农田地下水分及可持续利用提供科学依据。
The groundwater level of typical irrigated farmland in the piedmont region of Taihang Mountains has gradually declined since the 1970 s. Soil water dynamics and movement in the deep vadose zone under the irrigated farmland in the piedmont region of Taihang Mountains have not been further studied because of the difficult in obtaining data in the thick vadose zone. The soil water content and soil matrix potential under a typical irrigated farmland were monitored. The experimental site was chosen in Luancheng Agro-ecosystems Experimental Station of the Chinese Academy of Sciences, in which winter wheat and summer corn were planted. We carried out continuous monitoring on the soil water content and soi matrix potential for three years（October 1, 2011 to September 30, 2014）. A neutron tube with a depth of 1540 cm was installed to measure the soil water content. Seventeen tensiometers（Institute of Geographic Sciences and Natural Resources Research CAS） were installed for the measurement of soil water matric potential with a maximum depth of 800 cm based on an open caisson（with inner diameter of 1.5 m and depth of 9 m） whose inner sidewall was brick lined. Based on the measured data combined with the meteorological data of the study area, the soil water dynamics and movement was investigated. The results were as follows： 1） At the layer of 0-800 cm, the soil water content varied from 0.03 to 0.47 cm3/cm3 and the soil wate matrix potential was between-628.21 and 0 cm; Moreover, the distribution of soil water in the vertical profile was affected by the soil texture; 2） At the layer of 0-200 cm, the soil water content varied from 0.14 to 0.47 cm3/cm3 and the soil water matrix potential ranged from-628.21 to 0 cm; Soil water potential gradient changed significantly in this soil layer; Under the influence of infiltration and evaporation, the soil water could move upward or downward in this layer; 3） Below the root zone（200-800 cm）, the soil water content varied from 0.03 to 0.41 cm3/cm3 and the soil water matrix potential ranged from-311.79 to 0 cm, which implied that the soil water content approximately ranged from saturated situation to the field capacity and the velocity of the wetting front could be up to as high as 0.13 m/day below the root zone;The value of soil water potentia gradient was positive（positive potential gradient value means the downward direction of soil water movement in this study）thus soil water moved downward below the root zone; 4）The soil water matric potential changed from-311.79 cm to 0 cm and water potential gradient varied from 0.1 to 5.61 cm/cm at the layer of 200-600 cm; In the layer of 600-800 cm, the variation range of soil water content was 0.04-0.41 cm3/cm3 and the soil water matric potential varied from-138.18 and-45.57 cm; The variation range of soil water content was 0.03-0.35 cm3/cm3 and water potential gradient maintained approximately at the uni water potential gradient（1 cm/cm） below the depth of 600 cm; and 5） According to the soil water dynamics mentioned above the vadose zone from the depth of 0 to 800 cm could be divided into three layers： infiltration and evaporation layer（0-200 cm）unsteady infiltration layer（200-600 cm） and quasi-steady infiltration layer（600-800 cm）. This study is helpful for the more accurate estimation of groundwater recharge and provides data support for the sustainable utilization of groundwater.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2015年第19期128-134,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(41471027
41501035)
关键词
土壤水分
灌溉
地下水
太行山前平原
soil moisture
irrigation
groundwater
piedmont of Taihang mountain
作者简介
景冰丹，女，山西永济人，从事生态水文方向研究。石家庄中国科学院大学遗传与发育生物学研究所农业资源研究中心，050021。Email：maytime224@126．com
通信作者：沈彦俊，男，河北张家口人，博士，研究员，主要从事生态水文过程的研究。石家庄中国科学院大学遗传与发育生物学研究所农业资源研究中心050021。Email：yjshen@sjziam．ac．cn
