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

Thresh model is a precipitation tracking program, which is used to calculate various precipitation indexes to compare with the existing or experimental threshold of landslide occurrence. The program calculates the cumulative precipitation, precipitation intensity and precipitation duration, and compares the results with the threshold value to determine the threshold value used in landslide early warning. This command-line program is used with Python and shell scripts for input files and visualization results.

Class model, as the "second generation" surface model that people need, was developed for Canadian GCM in the late 1980s. The model will fully deal with the effects of vegetation, snow cover and soil on the heat and temperature of the atmosphere. Various land surface parameterization schemes are compared in international projects. The class model is tested in the coupling model with GCM and various experiments with pilps. In such an operating environment, class is proved to perform quite well.

HEC-HMS model is a watershed flood simulation system developed by the hydrological engineering center of the US Army Corps of engineers. It is a semi Distributed Rainfall Runoff Model with physical concept. According to the formation process of rainfall runoff, it is divided into four calculation parts: net rainfall process, direct runoff process, base flow and river confluence, which are mainly used to simulate runoff process in tree basin.

The soil water balance (SWB) model is used to calculate the spatial and temporal variations of groundwater recharge. The SWB model calculates replenishment by combining common geographic information system (GIS) data layers with tabular climate data.

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.