Dr3m is a distributed rainfall runoff model, which takes rainfall as input to calculate the rainstorm runoff through drainage pipeline or natural river. The detailed simulation of the rainstorm runoff period selected by the user is provided. The calculation of soil moisture is carried out every day during the rainstorm period. A watershed can be expressed as slope flow, channel and reservoir section, which together describes the drainage function elements of the basin. This model is usually used to simulate small urban basins. The flow and base flow in soil are not simulated, snow and snow melting are not simulated.

Wasp is a water quality model system proposed by the U.S. Environmental Protection Agency. It can be used in different environmental pollution decision-making systems to analyze and predict various water quality conditions caused by natural and man-made pollution. It can simulate hydrodynamics, one-dimensional unsteady flow of rivers, three-dimensional unsteady flow of lakes and estuaries, conventional pollutants (including dissolved oxygen, biological oxygen consumption, nutrients and algae) The law of migration and transformation of pollutants (including organic chemicals, metals and sediments) in water is called universal water quality model.

Integrated water flow model is a computer program used to simulate the flow of land surface, surface water and groundwater. It is a rewrite of IGSM software. Iwfm program and source code are provided free of charge. It uses finite element method to simulate groundwater flow. Surface water flow can be simulated by a simple one-dimensional flow network or by moving wave method. Allows users to run models for a specific period of time while editing input files. Iwfm simulates four land use categories: agriculture, urban, native vegetation and riparian vegetation. Land use area is divided into a time series with corresponding evapotranspiration rate and water management parameters. In the agricultural and urban land use categories, iwfm applies surface water and groundwater according to a specific ratio, and can selectively adjust surface water and groundwater to meet water demand.

Delft3D is a powerful software package developed by WL Delft hydraulics of Delft University in the Netherlands, which is mainly used in free surface water environment. The software has a flexible framework, which can simulate two-dimensional and three-dimensional flow, wave, water quality, ecology, sediment transport and bed topography, as well as the interaction among various processes. It is one of the most advanced hydrodynamic water quality models in the world. Delft3D system is widely used in the world, such as the Netherlands, Poland, Germany, Australia, the United States and so on, especially the United States has a long history of application. The Delft3D system has been used in Hong Kong since the mid-1970s and has become a standard product of the Hong Kong Environment Agency. Delft3D has been applied more and more in mainland China since the mid 80s, such as Changjiang Estuary, Hangzhou Bay, Bohai Bay, Taihu and Dianchi. Delft3D is the most advanced and complete 3D hydrodynamic water quality model system in the world, especially the unique support surface format.

Distributed hydrological model, water and energy prediction, geotop can be applied to very complex terrain, and integrates all surface energy balance conditions except water balance. For saturated and unsaturated subsurface flow, 3D Richard equation is adopted to realize accurate input of radiation parameters to obtain surface temperature.