Simulation of groundwater dynamic response to hydrological factors in karst aquifer system

A similar physical simulation experiment is a kind of generalization and reduction of real objects by similarity principle, which achieves the simulation of the actual situation. In order to reveal the influencing factors and mechanisms of the groundwater flow process in the karst aquifer system. In this paper, the hydrological cycle process of the karst aquifer system is comprehensively considered, and a conceptual model is established including hydrological factors such as rainfall recharge, epikarst zone, doline, fissure, conduit, and spring. Also, a three-dimensional physical model of karst fissure-conduit for experiments is designed and fabricated from the similarity with the groundwater channel structure based on the hydrological conceptual model. Moreover, karst aquifer under different rainfall conditions and aquifer structures is designed to simulate the process of seepage and recession. The experiments were divided into 24 groups, three times for each group. The experiment results show that (1) the rainfall intensity has a significant impact on the maximum peak flow, confluence time and flow duration of the spring flow process; (2) the epikarst zone has a vital influence on the confluence time, flow duration and curve shape of the spring flow process, and has little effect on the peak flow; and (3) the aquifer structure is the main factor affecting the initial flow, the slope of the recession curve and the recession coefficient of the spring recession process. Finally, this study indicates that the concept model is reasonable. The physical model for simulating the hydrological process can be applied to a wide range in karst aquifers, taking into account more geological factors.