在线技术在岩溶地下水示踪试验中的应用——以青木关地下河系统岩口落水洞至姜家泉段为例

Application of online technique in tracer test——A case in Qingmuguan subterranean river system,Chongqing,China

在岩溶水文地质调查的基础上,采用高分辨率野外自动化荧光仪、人工取样和放置活性炭的方法,对青木关地下河系统投放的示踪剂荧光素钠接收情况进行检测。结果表明:(1)姜家泉是青木关地下河系统的主要出口,岩口落水洞投放的示踪剂在姜家泉的回收量为93.9%,初现时间为33.3h,地下水最大视流速为222.2m/h,平均视流速为176.6m/h,众数视流速为172.1m/h,说明本试验段内地下径流为典型的紊流流态,岩溶含水介质极不均匀,可能有规模较大且无岔道的岩溶管道存在;(2)岩口落水洞与大木水窝泉、纸厂泉没有直接的水力联系,出口姜家泉与纸厂泉也无直接的水力联系;(3)野外自动化荧光仪精度和自动化程度高,携带方便,大大节约了试验成本,在我国西南岩溶区的地下水示踪试验中具有较大的推广和应用价值。

The recovering state of tracer fluorescent sodium being put into the Qingmuguan underground river is tested by means of high-resolution automatic field fluorometer and artificial sampling as well as adding active carbon after hydrogeologic survey. The results show that ： （1） The Jiangjia spring is the major outlet of the Qingmuguan underground river and 93.9 % of the total amount of tracer that has been put into the river at Yankou sinkhole is recovered. The time the tracer begins to appear is 33.3h; the maximum linear velocity is 222.2m/h and the dominant linear flow velocity 172.1m/h, the average velocity 176.6m/h. Those prove that the groundwater assumes typical turbulent flow in this tested section of the underground river, and the medium is quite uneven, or there could be large conduit without branches. （2） There is no direct hydraulic relation between Yankou sinkhole and Damushuiwo spring, Zhichang spring. There is also no direct hydraulic relation between the outlet Jiangjia spring and Zhichang spring. （3） Because the field automatic fluorometer is highly precious, quite automobile and handy, all this made the test very economical, so it is of high application value in tracer test in southwest China.