不同补给条件下裂隙岩溶含水系统演化规律

Evolution of Fracture-karst Aquifer System under Different Recharge Conditions

研究岩溶含水系统演化规律,对合理利用岩溶水资源及岩溶工程建设有重要意义。以Fracture To Karst程序为基础,耦合地下水渗流模型和溶蚀动力学模型,构建裂隙岩溶含水系统二维剖面演化模型,模拟不同补给条件下裂隙岩溶含水系统的演化规律。模拟结果表明,在演化过程中,两种系统的水位逐渐下降,泉排泄点减少,最终在侵蚀基准面处形成大泉;系统的差异溶蚀形成优势裂隙,袭夺河流补给水流和降雨补给水流,最终形成岩溶管道,降雨补给系统的溶蚀集中在潜水面附近,河流补给系统的溶蚀则向深层裂隙拓展。不同补给条件形成了不同的泉发育模式,降雨补给系统,泉由汇向源发育,而河流补给系统,泉由源向汇发育。研究成果为预测岩溶发育程度、分析岩溶发育规律和构建合理的演化模型提供了依据。

It is important to study the evolution of karst water system,which is of great significance for rational utilization of karst water resources and karst engineering construction.Based on Fracture To Karst program,coupled groundwater seepage model and dynamic dissolution model,this paper established two-dimensional profile evolution model to simulate the evolution of fracture-karst aquifer system under different recharge conditions.It is found that with the evolution of fracture-karst aquifer system,the water table is declined,which lead to reducing number of spring excretion points and big spring being formed on the base level of erosion.The variance dissolution forms the dominant fractures,which lead to capture rainfall and river recharge flow and form the karst pipeline.The fractures are corroded on the corrosion in the river recharging system,but the corrosion expands to deep fracture in the river recharge system.Different recharge conditions form different spring development modes.It is also found that in rainfall recharged system,the springs develop from the sink to the source;while in river recharged system,the springs develop from the source to the sink.The simulation results provide scientific basis for the prediction of karst development level,the analysis of regularity of karst growth and the construction of the reasonable evolution model.