## 1 Introduction  
Numerical groundwater simulation is derived from mathematics and computer technology that quantitatively analyzes groundwater seepage and solute transport processes and patterns [1]. The quantitative study of groundwater seepage has gradually developed from one-dimensional steady flow models to three-dimensional unsteady flow models since 1856 when [PERSON] proposed his formula based on sand tank experiments. The models also developed from physical simulation methods to computer numerical simulation models. Numerical simulation can well reflect the groundwater movement under complex hydrogeological conditions and has a high degree of simulation, and the credibility of the results from the model mainly depends on the accuracy of the actual hydrogeological conditions when the model is built. How to correct the model parameters to improve the accuracy of numerical simulation and obtain more accurate groundwater movement is of great significance to the study of the change of pollution concentration and the simulation prediction of the pollution spreading range of the site. As computer technology developed, the numerical simulation of groundwater gradually developed towards large-scale, refined multi-coupling models [2]. The U.S. Geological Survey developed MODFLOW in the 1980s. It is a numerical simulation model for groundwater flow based on the three-dimensional finite difference method, marking the maturity of numerical simulation methods for groundwater flow [3]. A series of software developed based on MODFLOW for groundwater flow simulation and solute transport, such as Visual MODFLOW, GMS, and Visual MODFLOW Flex, have been widely used in many industries such as scientific research, urban and rural planning, environmental protection, and water resources planning [4; 5; 6; 7]. This software relies on an aesthetically pleasing graphical user interface (GUI) that allows users without programming skills to build complex models through the GUI [8]. This software has greatly enriched the range of applications of groundwater simulation software and promoted the development of numerical groundwater simulation technology. [PERSON] et al. [9] developed a three-dimensional unsteady flow model of anisotropic karst fissure aquifer based on equivalent continuum to predict the temporal and spatial changes of groundwater level and temperature in the study area, and the prediction results show that reinjection can effectively slow down the decline of the hot water level in the ground. [PERSON] et al. [10] developed a two-dimensional numerical model of groundwater to simulate the flow of groundwater and the migration of pollutants in porous media, and it can consider the effects of adsorption, blocking and volatilization on the pollutants at the same time. However, this software also limits the research space for most users [11]. The great portability of most numerical groundwater flow simulation software means that the user can only interact within the scope of the features it provides [12; 13]. Diversification and crossover between the numerical groundwater flow simulation and other fields still requires a return to programming [14]. Secondary development on software such as MODFLOW, which is developed using a programming language such as Fortran, is a great challenge for most people involved in groundwater research. The emergence and rapid development of the Python computer language for object-oriented programming sparked hope that numerical groundwater simulations would return to a programming approach and usher in a new boom [15]. FloPy is the first Python library for the numerical simulation of groundwater flow and solute transport. It can interact with numerical simulation software such as MODFLOW, MODFLOW6, MT3 DMS, and SEAWAT, to build numerical groundwater models [16]. Python's wide variety of application libraries enables many types of scientific calculations and model couplings with only a small amount of code.