典型岩溶槽谷区地下河水文动态响应研究——以重庆青木关地下河为例

Study on hydrologic regime of underground river in typical karst valley——A case study on the Qingmuguan subterranean stream in Chongqing

为了更好地掌握重庆青木关地下河水文动态变化规律,2007年5月至2008年6月利用WGZ-1型光电数字水位计和水质监测仪(CTDP300型在线水质分析仪),对降雨量和地下河水位、水温、pH及电导率进行了连续自动监测,并采用水文动态曲线线型分析法分析了该地下河水文动态变化对降水事件的响应。结果表明,地下河水文动态对降雨响应迅速,水位流量过程曲线线型呈不对称尖峰型,尤其在2007年7月17日出现的大暴雨事件中,最高水位为1.175m,滞后最大雨强6h10min,最大流量为2.5781m3/s,而观测中该地下河最小流量仅为0.0189m3/s,反映出该岩溶地下河发育强烈,赋水空间较单一,含水层对水资源调蓄能力较弱。电导率、pH和水温对降雨也同样表现为快速响应,电导率由602.7μs/cm降到462.09μs/cm,pH由7.23降到7.01,水温由18.9℃上升到19.5℃,各指标滞后不超过15h。

In order to grasp the hydrologic regime of underground river, a case study on the Qingmuguan subterranean stream in Chongqing was carried out. During May 2007 to June 2008, a water table gauge （WGZ-1 photoelectric figure fluviograph monitor） and water quality monitoring site were set up to record the water level, temperature, pH and conductivity. Hydrology dynamic method was adopted to analyze the response of hydrologic dynamic of the subterranean stream to the rainfall in this paper. The result showed ,during the rainfall, water table and discharge increased with the rain, especially on July 17, 2007, some peaks appeared in the large storm, the highest water level was 1. 175 m, and the response lagged for 6 h10 min after the largest rainfall intensity with the highest discharge being 2. 578 1 m^3/s and the smallest only 0. 018 9 m^3/s. It was found that there was a significant correlation between the water table regime and rainfall event, which indicated the Qingmuguan subterranean stream is developed intensity in tensity with single conduit and weak water-storing ability. Conductivity. pH and water temperature also responded to the rainstorm rapidly. Conductivity fell down from 602.7 to 462.09μs/cm, pH fell down from 7.23 to 7.01, and water temperature risen from 18.9 ℃ to 19.5 ℃, all these indexes lagged shorter than 15 hours.