摘要
积雪覆盖作为中国北方高寒黑土区土壤冻融期最普遍的上边界条件,直接影响土壤水分分布、迁移过程及土壤温度、冻结深度、冻结速率等。通过野外试验,对哈尔滨地区的季节性冻融黑土在裸地、自然积雪、压实积雪、加厚积雪4种不同覆盖条件下的土壤水分迁移规律进行动态观测。从时间、空间角度分析土壤含水率变化,结果表明:积雪厚度和密度都可以很大程度上影响积雪对土壤的保护作用,在仅考虑积雪自身沉降造成密度增大的情况下,积雪厚度越大保护效果越好,土壤含水率对气温变化的响应及土壤解冻时间依次延后,延后程度随土壤深度增加而增大;当人为改变积雪密度时,相较于单纯增加积雪厚度,密度大的积雪可以更好地保护土壤,使气温对土壤的直接影响更小。当遇到冬季降雪量较小的情况时,可以考虑采用人为压实积雪的方法,加强对土壤的保护作用。
Snow cover,as the most common upper boundary condition during freezing and thawing period in the cold region of northern China,directly affected the soil moisture distribution and movement,soil temperature and frozen depth,freezing rate,etc. In order to reveal the influence of snow on soil moisture movement,soil water and heat coupled transfer during freezing and thawing period was studied. Through field experiment,the soil moisture movement patterns of seasonal freezing-thawing black soil in Harbin were dynamically observed under the conditions of four different coverages： bare land,natural snow,compacted snow and thicken snow. The density and liquid water content of snow were measured by the Snow Fork,the liquid water content and total water content of soil were measured by time domain reflector and neutron moisture meter. From the perspectives of temporal and space change of soil moisture content,the results indicated that the thickness and density of snow can largely affect the protection of snow on soil,when only considering the subsidence of increased snow density,the greater the thickness of snow was,the better the protection was. The response of soil moisture content to temperature change and soil thawing time were delayed,the degree of delay was increased with soil depth increasing.Compared with increase of snow thickness,denser snow can protect the soil better,and the influence of temperature on soil was decreased. When winter snow was small,farmers can artificially compact it,which can strengthen the protection of soil.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2015年第10期152-159,共8页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金资助项目(51279031
51209039)
黑龙江省自然科学基金资助项目(E201241)
教育部新世纪优秀人才支持计划资助项目
黑龙江省杰出青年基金资助项目(JC201402)
中国博士后科学基金资助项目(2012T50321
2011M500632)
关键词
积雪消融
压实积雪
土壤液态含水率
水分迁移
Snow melt Compacted snow Liquid soil water content Soil moisture movement
