Based on the gradual flow equation, the flow characteristics of open channel are simulated, and the flow velocity and depth are calculated. The fldta model is not a separate model. The code can obtain the fldta. F file in the Midas model source code

Biome BGC model is a calculation program for assessing the energy, water, carbon and nitrogen flux and storage of vegetation and soil components of terrestrial ecosystems. The main purpose of this study is to study the interaction among global climate, disturbance and biogeochemical cycle. It represents the flux of energy and mass controlled by physical and biological processes.

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.

HSPF (hydraulic simulation program - FORTRAN) model is a mathematical model developed by the U.S. Environmental Protection Agency (EPA). It is used for continuous simulation of hydrological and water quality processes in a large watershed under natural and artificial conditions. The model is written in FORTRAN language and based on Stanford hydrological model. It can comprehensively simulate runoff, soil loss, pollutant transport, river hydraulic and other processes, and is widely used in the scenario simulation of watershed water environment effects of climate change and land use change. The model is an excellent representative of semi distributed hydrological and water quality model, HSPF model is widely used in foreign countries. HSPF model includes perlnd, implnd and rchres to simulate the hydrology and water quality of permeable section, impervious section and surface water body respectively. Generally speaking, HSPF model plays an important role in the simulation of hydrology and water quality process in foreign countries, as well as scenario analysis involving climate change and land use impact, But the application of this model in China is very limited