示踪法定量分析水流连通问题

为定量分析地下水流的水量分配比例，进行了连通试验。试验以示踪剂罗丹明为媒介，利用其受特定波长光照会激发荧光的特性，采用高分析度荧光分光光度计探测示踪剂溶液荧光强度，进而建立示踪剂浓度-荧光强度曲线。试验中在某地域上游溶洞入口投放示踪剂，并在下游出口回收样品，探测其荧光强度，同时进行流量测量。根据已建立的示踪剂浓度-荧光强度曲线分析计算，得出样品中示踪剂的质量，进而根据物质质量守恒定律和示踪剂运移扩散理论推算得到上下游水量分配比例。通过试验结果分析发现：采用本方法能较准确地探测出上下游水量的分配比例，试验方法可行，结果可信，可为解决类似问题提供参考。

Quantitative Analysis of Flow Connectivity by Tracing Method

Groundwater connectivity test was conducted to investigate the hydraulic connection between caves in the upstream and the downstream, and to quantitatively determine the ratio of water flow into the downstream caves. Rhodamine, which would be fluorescent illuminated by light of certain wavelengths, was used as tracer medium. Fluorescence spectrophotometer was employed to detect the intensity of fluorescence in the tracer solution, hence obtaining the curve of concentration vs. fluorescence intensity. The tracer was put at the entrance of Karst cave in the upstream, and water samples were collected at the exit in the downstream to detect the fluorescence intensity and measure the flow. According to the obtained curve, the tracer quality in the sample was calculated. Subsequently, the water allocation ratio was derived from the law of mass conservation and the theory of tracer transport and diffusion. Results showed that during the test period, 89% of the water flowed from caves in the upstream into the downstream. The relation between fluorescence intensity and tracer concentration is also believed to be feasible for quantitative analysis. The test method could be a reference for similar engineering practices.  