一、潜流水——流域里最大的一宗待开发的水资源通常在地面上的降水量中,只有少量成为迳流,大部分渗入地下,存于土壤包气层里,随即蒸腾蒸发,或渗透到地下水面,参与潜流。后者就是流域里最大的一宗水资源,可以开发利用。例如海河流域平原12.1万方公里上降水P↓年平均570毫米,合年687亿方水(以 First, the submarine water - the largest in the basin to be developed water resources usually precipitation on the ground, only a small amount into the inflow, most of infiltration underground, stored in the soil layer, then evaporate, or Infiltrate into the groundwater and participate in the subsurface flow. The latter is the largest water resource in the basin and can be exploited. For example, the Haihe River Basin plain 121,000 square kilometers of precipitation P ↓ an average of 570 mm, a total of 68.7 billion cubic feet of water