水势理论在四水转化研究中应用时代特征与趋势:纪念ZFP方法引进我国30周年

20世纪80年代零通量面方法在我国应用中解决了"四水"转化研究中参数不确定性带来的问题,发现在降水入渗补给地下水过程中土壤总水势梯度大于1.0cm H2O/cm,且逐渐降低,流入、流出被监测土层的水量相等时土壤总水势梯度趋近于1.0cm H2O/cm。20世纪90年代,利用土壤水势与含水量之间量化关系,指导了农业节水灌溉,提出在灌溉过程中土壤水势梯度等于1.0cm H2O/cm的时间持续愈长,表明过剩灌溉而浪费的水量愈多的认识。进入21世纪以来,水势理论较广泛地用来解决土壤水盐分运移数值模拟与入渗模型中水文地质参数问题和降水入渗土壤水势运移微观机理研究,并发现表聚型、中聚型和底聚型土壤盐分剖面的水动力学特征。通过土壤水动力场调控改变土壤水盐(养分或污染物)运移是未来重要研究方向。

Application Characteristics and Trend of Soil Moisture Potential Method

In 1980s,the Zero Flux Plane method is applied to solve the problems from the uncertainty parameters in the transformation of the precipitation,surface water,soil moisture and groundwater in our country,which shows that the total soil moisture potential gradient is greater than 1.0 cm H2O/cm in the process of the precipitation infiltration of groundwater supply and gradual reduction,and indicates that the total soil moisture potential gradient is approaching to 1.0 cm H2O/cm flowing in and out of the water by monitoring soil layers.In the 1990s,the relationship between the soil water potential and the soil water content to guide the agricultural water saving irrigation demonstrates that the excess irrigation and more water waste can be realized when the soil moisture potential gradient is approaching to 1.0 cm H2O/cm and soil is longer in the process of irrigation.In the 21 century,the groundwater numerical simulation rise again.The soil moisture potential theory is used to solve the soil water salt migration.Numerical modeling and the hydrogeologic parameters in the infiltration model is introduced to water gas migration change mechanism.The different characteristics of these polymer profiles are in different hydrodynamic condition.The soil moisture potential-gradient profiles point to the surface.Its absolute value is much larger than 1.0 cm H2O/cm with the formation of salt accumulation to the upper of the soil profile.The soil moisture potential gradient point to groundwater table in the upper of the profile and point to the surface in bottom of the profile with the formation of salt accumulation to the middle of the soil profile.The soil moisture potential gradient profiles point to groundwater table.Its value is much larger than 1.0 cm H2O/cm with the formation of salt accumulation to the bottom of the soil profile.