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.

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.

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.