本讲讨论地下水的第二个基本类型——自流水(或又称“承压水”和“层间水”)。它乃是指埋藏于顶底板都是不透水层的含水层中的承压地下水。当钻孔打穿不透水顶板揭露该含水层时,其中承压的地下水便会在水头的作用下上升到顶板以上的某一高度。该高度的大小决定于承压水头的大小。在条件适当时水可流出地面形成钻孔的自流(自喷)。自流孔因为取水时不必花费动力被人们广泛地利用于供水和灌溉,例如我国北京,包头等地都是利用自流孔取水。法国有一个省即名为自流省,在该省境内广泛利用自流孔取水,“自流水”的名称即由此而来。但我们一定要 This talk discusses the second basic type of groundwater - gravity water (also known as “confined water” and “interlayer water”). It means confined groundwater buried in aquifers where the roof and floor are impermeable to water. When the borehole pierces the impervious roof to expose the aquifer, the pressurized groundwater will rise to a height above the roof by the head. The height depends on the size of the pressure head. Water can flow out of the ground to form a run-of-the-mill flow (self-blasting) when conditions permit. Self-flow holes because water does not have to spend power without being widely used in water supply and irrigation, such as China’s Beijing, Baotou and other places are using self-flow holes to take water. In France, a province is known as the “Ziliuocheng”. Its name is derived from the widespread use of self-flow holes in the province. But we must