论文部分内容阅读
该项试验是以现场试验为主,并开展了相应的室內试验。本试验提出了将土壤冻融期划分为初冻期,正冻期和消融期三个阶段,以利于对水盐动态进行科学分析。总结出了土壤冻结深度与气溫负积温的定量关系及经验表达式,得出水分迁移补给以液态水为主的结论,提出了正冻期土层含水量与封冻时初始含水量的定量关系及经验表达式,正冻期含水量,冻土层增水量和潜水消耗量与地下水位埋深的关系。发现了在正冻期不同土质在一定的地下水埋深范围内,潜水蒸发消耗量最大,和非冻结期有着不同的变化规律。提出了冻土层增盐量与潜水入流量和矿化度间的定量关系及经验表达式,提出了经冻融循环出现“盐增碱减”的现象,提出并测试了“秋潮”期土壤水分变化规律。试验成果为河套地区的规划设计,灌排水管理与防治次生盐渍化提供了主要参数和科学依据。
The test is based on field tests, and carried out the corresponding indoor test. The experiment proposed that the soil freezing and thawing period should be divided into three phases: initial freezing period, normal freezing period and ablation period to facilitate the scientific analysis of water and salt dynamics. Summarized the quantitative relation and empirical expression of the soil freezing depth and temperature negative accumulated temperature, the conclusion that the water migration and recharging is mainly liquid water is concluded, and the quantitative relationship between the moisture content in the soil layer during the freezing period and the initial moisture content at freezing is proposed And empirical expressions, the water content of the normal freezing period, the amount of water permafrost and the amount of diving consumption and the depth of groundwater table. It was found that in the period of normal freezing period, the soil water consumption of the submersibles was the largest in different groundwater depths, and varied with the non-freezing period. The quantitative relationship between the salt content in the permafrost and the inflow and salinity of the subducted water and the empirical expression are put forward. The phenomenon of “increasing salt and reducing alkali” appears in the freezing and thawing cycle, and the “autumn tide” period Soil moisture changes. The experimental results provided the main parameters and scientific basis for the planning, design, irrigation and drainage management and secondary salinization prevention and control in Hetao area.