地中蒸渗计水分运移机理及其监测误差分析

Analysis on the Difference and Error of Trans-mechanism of Moisture between the Lysimeter and the Natural Unconfined Groundwater System

对地中蒸渗计与自然潜水水分运移机理存在的差异及误差进行了分析。结果表明:地中蒸渗计与自然潜水在水位动态、水分存储、水分运移等方面存在一定的差异,使得利用地中蒸渗计监测的潜水蒸发量、降雨入渗补给量与自然潜水的实际情况产生了一定的误差,这种误差随着潜水埋深的变化而变化,潜水埋深越浅,误差越大,潜水埋深越深,误差越小。特别对于潜水埋深小于1.5m的地中蒸渗计,使用其资料时一定要作适当的技术处理,如果直接引用,将会给计算成果带来较大的误差。

The paper analyzed the difference and the error of trans-mechanism of moisture between the lysime-ter and th e natural unconfined groundwater system.The result shows that the water table dynamic,the moisture storage,the moisture transport and so on exist some different in the lysimeter and in the natural condition.That caused the error compared with scene of natural condition in groundwater evaporation and its precipitation infil-tration recharge as well as the error varies on the groundwater table.The less deep-water table under ground,the greater error follows.Especially,measured data of water table within1.5meters under ground should make a technical treatment.Otherwise,it would lead an even greater error.