The UNMIX model is a mathematical receptor model developed by scientists from the U.S. Environmental Protection Agency. It provides scientific support for the development and review of air and water quality standards, exposure studies and environmental forensics. UNMIX can analyze a wide range of environmental sample data: sediment, wet deposition, surface water, ambient air and indoor air.

Gawser is a temperature index snow melting model which can be used to verify the hydrology of the basin. It is most suitable for agricultural or forest watersheds, but can be used to demonstrate the hydrology of other types of watersheds, such as urban or suburban water sheds. Gawser is suitable for basins with different development levels and can be used to show the impact of development on watershed hydrology. For example, in order to observe the hydrological impact of deforestation on agriculture, data can be used to simulate hydrological conditions in forest basins, and then reprogrammed to simulate hydrology in agricultural watersheds. We can study the behavior of runoff, infiltration, base flow and other hydrological conditions in each watershed.

3dade is a FORTRAN computer program, which is used to evaluate a series of analytical solutions of the three-dimensional convection dispersion equation. The analytical solution has stable unidirectional flow in porous media with uniform flow and transport characteristics. The transport equation includes the transport of solute by convection and dispersion, as well as solute delay, first-order decay and zero order production. The 3dade code can be used to directly solve some problems, that is, centralized calculation of time and space functions as specified model parameters, and indirect (inverse) problems, in which the program estimates the selected parameters by fitting one of the specified analytical solutions.

GSFLOW The model is developed by the U.S. Geological Survey to simulate the interaction between surface water and groundwater. The model considers the relationship between meteorological conditions, surface runoff, groundwater runoff and the interaction between surface water and groundwater. It is coupled with the rainfall runoff simulation system PRMs and the three-dimensional finite difference model modflow-2005. The model is suitable for the simulation of non spatial and temporal scales In order to evaluate the impacts of land use change, climate change and groundwater exploitation on surface hydrological process and underground hydrological process.