2 research content editing
(1) The basic concepts, basic laws, basic equations, definite solution conditions and the establishment and solution of mathematical models of porous media and seepage are the basic theories and key contents.
(2) the movement of groundwater to rivers and canals (divided into the stable movement of groundwater between rivers and canals and the unstable movement of diving between rivers and canals); Groundwater movement law (horizontal movement law) in irrigation and drainage area.
(3) the movement of groundwater to the well and the calculation method of parameters, focusing on the stable and unstable movement of groundwater to the complete well; The movement law of groundwater in the well area is vertical.
(4) The movement of groundwater to incomplete wells and boundary wells.
(5) Theory of groundwater movement in unsaturated zone (infiltration and phreatic evaporation, etc. ).
(6) Hydrodynamic dispersion theory, mainly including hydrodynamic dispersion phenomenon and mechanism, and the study of convection dispersion equation and its solution.
(7) Some problems in groundwater movement (solute migration law in groundwater, water migration law in vadose zone, etc.). ) and laboratory methods.
3 research method editor
In groundwater dynamics, analytical method, physical simulation method and numerical simulation method are mainly used to study the problem.
(1) analysis method
Analytical method refers to solving mathematical expressions or equations (including ordinary differential equations and partial differential equations, etc. ) is transformed from groundwater dynamics problem by analytical method. This method is clear and easy to realize, but the analytical method can only solve the simple seepage problem (limited by the analytical method of equations), and the more complicated groundwater dynamics problems must be solved by the latter two methods.
(2) Physical simulation method
Physical simulation can be used to study the complicated groundwater dynamics. Physical simulation method refers to an experimental method to reproduce the dynamics and process of groundwater flow with similar models. It can not only simulate complex problems that are difficult to be solved by analytical methods, but also can not be separated from physical simulation methods when testing basic theories and observing some physical phenomena that may occur in the flow process, such as piping and dispersion. However, due to some inherent limitations of physical simulation methods, physical simulation methods have been basically replaced by numerical simulation methods in solving practical hydrogeological problems.
(3) Numerical simulation method
For a mathematical model describing the actual groundwater system, its analytical solution is generally difficult to find. Numerical method refers to finding the solution of an equation that cannot or is not easy to be solved by analytical method. This method usually needs the help of a computer to get an approximate solution with variable precision.
There are many numerical methods to solve groundwater problems, but the most commonly used methods are finite difference method (FDM) and finite element method (FEM).