Groundwater (Senden, railway line N4) Upper groundwater layer

The measuring point Senden, railway line N4 (measuring point no.: 9880) is used to monitor the groundwater level in the upper aquifer.N4号铁路线路沿线的森登（Senden）监测点（监测点编号：9880），用于监测上层含水层（upper aquifer）的地下水位。