Their most important traditional use was for grinding grain, though in certain areas their use in landdrainage and water pumping was equally important.
风车最主要的用途是磨粉，在某些地区用于灌溉土地和抽水，其作用也同样重要。
2
If the water table intersect the land surface, groundwater will flow out onto the surface at springs, whether to be collected there or to subsequently flow farther along a drainage.
如果地下水位与地表相交，地下水将在泉水处流出地表，聚集于此或是随后沿着排水系统进一步流动。
3
They include the brown mudfish in New Zealand, whose wetland habitats have been virtually destroyed through drainage schemes, irrigation and land development.