When the system is confinedwell, the change of observation water level has a linear relation with water head change.
在系统封闭很好的情况下，观测水位的变化基本与水头的变化呈线性关系。
2
Arsenic AND WELL water: The world's worst toxic problems are not confined solely to industrial pursuits.Arsenic leaching into groundwater afflicts some 750,000 people, largely in south Asia.