PROTECTION AND RESTORATION OF HEILONGTAN GROUNDWATER SYSTEM IN LIJIANG, YUNNAN, CHINA
The observational data during 1955-2013 show that Heilongtan Springs has significant interannual variation in discharge (0~8042×104 m3/year). Since the July2011, the discharge of Heilongtan Springs reduced significantly for the declining precipitation. In order to ensure sustainable water, the local government planning to divert water from the Heibaishui River to the recharge area of Heilongtan.
Base on the hydro-geologic survey, geophysical exploration and drilling in recharge(Jiuzihai) and discharge (Heilongtan) area, and two groundwater tracer tests (2013/2014), it shows that:
1 Analysis of the tectonic process, lithology, groundwater recharge and discharge characteristics, chemistry characteristics, show that Jiuzihai-Heilongtan is a unified hydrogeological units.
2 According to cluster analysis of groundwater chemical composition, Jiuzihai is closely related to a series of southern springs(including Heilongtan Springs); inverse Hydro-geochemical simulation (Phreeqc) confirmed the runoff path between Jiuzihai and Heilongtan Springs.
3 Tracer tests showing: the breakthrough curve of iodide ions and AR94 has multiple peak values(The distance is 16.7 km, seepage velocity is 804-815m/d). This illustrates that there are multiple and large karst groundwater flow channel between recharge area and Heilongtan.
How much water in the diversion would not affect the ecological environment of Heibaishui River; how much water will effectively supply the downstream springs(including Heilongtan Springs), and would not submerged the city at the same time. These will be the focus in the next stage.