落水洞直径对岩溶泉流量影响的试验研究

温忠辉+张依楠+苏佳林

摘要：基于裂隙-管道介质物理模型，通过设计多组试验方案，研究落水洞直径的改变对岩溶含水系统调蓄能力及泉流量过程的影响。经试验数据分析发现：调蓄系数随着落水洞直径增大而增大；在低强度下，落水洞直径的改变对裂隙和落水洞共同释水阶段的衰减能力影响不大，而在高强度下，其衰减能力随着落水洞直径的增大明显减小；底部管道释水阶段的衰减系数不受补给强度和落水洞直径的影响，其值约为0.0017 1/h ；调蓄系数与第一阶段衰减系数的乘积与落水洞直径无关，与补给强度呈负相关关系。

关键词：岩溶泉流量；物理试验；落水洞直径；调蓄系数；衰减系数

中图分类号：P641 文献标识码：A 文章编号：1672-1683（2017）04-0111-06

Abstract：Using the physical model of fissure-conduit media，we designed several experiments to study the effects of sinkhole diameter variations on the storage capacity and spring flow process of the karst aquifer system.Data analysis revealed that the regulating coefficient increased with the increase of sinkhole diameter.At low recharge rates，the variation of sinkhole diameter had little effect on the attenuation capacity at the stage where the fissure and sinkhole released water simultaneously.However，at high recharge rates，the attenuation capacity obviously declined with the increase of sinkhole diameter.The attenuation coefficient at the stage where the bottom pipeline released water was about 0.0017 1/h，and it was not affected by the recharge rate or the sinkhole diameter.The product of the regulating coefficient and the attenuation coefficient of the first stage was negatively correlated to the recharge rate，but was independent of the sinkhole diameter.

Key words：karst spring flow；physical experiment；sinkhole diameter；regulating coefficient；attenuation coefficient

1 研究背景

在我國西南岩溶地区，虽降水充沛，但由于该地区的落水洞、岩溶漏斗、地下河天窗等地表岩溶地貌极其发育，大气降水及地表水会沿着这些岩溶通道集中入渗补给地下水，从而导致地表水匮乏，人水矛盾突出[1]，并且水资源短缺问题将随着岩溶地貌进一步发育而更加严重。近年来，许多学者对西南岩溶地区含水系统水动力特征展开研究，以便为解决水资源问题提供有力的理论支撑。

落水洞作为岩溶垂直发育阶段的产物，是岩溶含水介质内主要的集水区域和过流通道[2]。其在形成的初始阶段，侵蚀作用以沿垂直裂隙的溶蚀为主。当孔洞扩大以后，补给强度很大时，大量地表水流集中汇入落水洞，水流所携带的大量泥沙石砾不断地对洞壁四周进行磨蚀，同时还会伴随着岩体的崩塌，使落水洞迅速扩大[3]。……