3D focal mechanisms is an observation tool for 3D focal mechanism symbols. The tool runs in ArcScene 9. X, a geographic information system software of ESRI. The program needs to input a GIS point data set of earthquake location, which contains the strike, tilt and tilt values of node plane of each earthquake. Other information, such as the depth and magnitude of the earthquake, may also be included in the dataset.

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

CROPWAT is a model developed by the food and Agriculture Organization of the United Nations (FAO) in 1991. It can help agrometeorologists, agronomists and irrigation engineers to calculate evapotranspiration and irrigation water requirements in a standard way. In addition, CROPWAT can suggest how to improve irrigation methods, plan irrigation schedules under different water supply conditions, and evaluate the impact on crop yields under rain sampling conditions or under sufficient irrigation conditions. The basic functions of CROPWAT include: (1) reference crop evapotranspiration (2) crop evapotranspiration (3) crop irrigation water requirement (4) formulation of irrigation schedule (5) evaluation of crop yield under rain fed or under sufficient irrigation conditions.

One dimensional River Stuart model

PHREEQC is a computer software (Parkhurst and appelo, 1999) for the calculation of various low-temperature hydrogeochemical reactions. PHREEQC, based on the ion linked water model, can (1) calculate the species and saturation index of matter formation; (2) simulate geochemical inversion process; (3) calculate batch reaction and one-dimensional migration reaction. In addition, PHREEQC coupled with multi-component solute transport model can generate PHAST, a three-dimensional reaction transport simulator for simulating groundwater flow system. PHREEQC is also useful in the investigation of unpolluted and polluted environment, laboratory, field and regional investigation. PHREEQC can investigate various natural and human influenced environmental geochemical reactions, including acid mine water discharge, radioactive waste isolation, pollutant migration, nutrient enrichment, aquifer natural and artificial restoration, aquifer reserve recovery, drinking water treatment, indoor experiment and regional aquifer system. PHREEQC has two graphical user interfaces available. Phreeqcl is a screen driven interface that provides a descriptive explanation for each data item (Charlton and Parkhurst, 2002). PHREEQC used in windows is a row editing object interface. Its additional input features enable it to generate graphic simulation results (post, 2004). 　

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.