At last, taking the dialing Xincun slope harnessing engineering as the example, the slope stability under the affection of rainfall and the application of drain ditch and drain hole are accounted for.

In the meantime the time variation of the water level in the ditch has been taken into account, therefore the groundwater head are time-varying as the groundwater flows toward the drain system.

With decompress well and drainage ditch to drain and decompress can effectively reduce groundwater level and prevent immersion outside reservoir.