Drought causes and restoration measures for Jiulongchi spring group within Cuihu lake, Kunming

The Jiulongchi spring group is located in the northern part of the Kunming basin. The karst aquifer system in this area extends from the bare karst mountain zone of the Sheshan hill to the loose soil zone at the bottom of the Kunming basin. Due to the facts that the soil layer of Cuihu lake district is very thin and groundwater infiltration is blocked by the clastic rock strata at the southern side, the groundwater rises and overflows the surface over a short period, forming the Jiulongchi spring group. The Jiulongchi spring group is not only the source of Cuihu lake, but also one of the sources for Dianchi lake. The drought of the Jiulongchi spring group reflects serious deterioration of the water environment in Dianchi lake basin. Based on dynamic groundwater monitoring data from the 1960's, groundwater exploitation data, groundwater drainage excavation and the expansive rocky desertification in the groundwater recharge area of Sheshan karst hill, it is proved that the unsustainable large-scale development and underground channel construction in the area were the primary causes of the drought of the Jiulongchi spring group. Many of the restoration measures are very effective, such as closing production wells, shutting down underground shelters, and transferring long-distance water from outside of Dianchi basin into the basin. It is noted that the groundwater level around the Jiulongchi spring group started to rise after the measures were implemented.