At present, the plastic tarpaulin used in soil fumigation process has been proved to be able to penetrate into the fumigation steam and cause obvious loss to the atmosphere. New low permeability membranes are being developed to reduce fumigant emissions and improve efficacy. A fast, reliable and sensitive method is needed to measure the permeability of various membranes that may be used in new management practices. Filmpc provides a method for estimating the mass transfer coefficient (H) of fumigants in agricultural films. H is a measure of diffusion resistance. Unlike other permeability measurement methods, h is an attribute of film chemical combination, independent of the concentration gradient of the whole film. The model relies on a mass balance method, and adsorption and diffusion are carried out on the membrane. The results show that this method produces a sensitive and reproducible method for measuring membrane permeability.

Calite model is an interactive screening model planned and managed by the state water project (SWP) and the Central Valley Project (CVP) in California. It simulates the hydrology of the Central Valley, reservoir operation and delivery allocation decisions to SWP and CVP, delta salinity response to changes in river flow and outlet, and resident ecosystem index. The power of filtering models like callite is the ability to quickly simulate system operations and merge changes relatively easily. The current version of calite simulates the operation of the system on a monthly basis. On the latest modeling computer, it takes about 6 minutes (compared with 30 minutes of calsim), recording a full 82 years of records (water year 1922-2003). Scenarios can be run using a variety of different user specified parameters related to hydrometeorology, requirements, facilities and infrastructure, regulations, and system operations. Through the integrated post-processing tools of the model, we can observe, compare and analyze the results.

Pihm is a physical model of land surface and groundwater, closely coupled to GIS interface. Pihmgis is open source, platform independent and extensible. Through the development of shared data model and hydrological model data structure, the close coupling between GIS and model is realized.

SPARE:WATER It is a spatial decision support system for estimating water consumption of agricultural production system. It is a stand-alone software application that integrates a database for mathematical models and graphical user interfaces (GUIs) for estimating crop water requirements. The software realizes the function of GIS, which is used to manage spatial data based on open source spatial database.

Elm is mainly used to develop and share a better understanding of biological, chemical and hydrological interactions in landscape mosaic ecosystems. In the field of ecology, models can help organize or integrate our understanding of system ecology. This understanding can be applied to assess the relative benefits of simulation scenarios that will change in the future.