ENKI consists of a simulation core, a library of process-simulating subroutines, and a front-end program containing the graphical user interface (GUI). The operational version uses the same core and a subset of the routine library, and will be encapsulated within Powel's SmG system. It will thus be tightly coupled with SmG's database solution and software suite, and operated through SmG's user interface.
The basic function of Enki is to assemble a model from a library of subroutines, and to run this model for a specified time period and geographical region. All process data are GIS objects; in raster form, as point-vector data, or as discrete variables (scalars). Each subroutine implements the set of simulation equations performing a particular subtask in the model. Subtasks are not restricted to hydrology, and the model can be extended to simulate water temperature or quality, vegetation growth, or other ecosystem dynamics simply by adding new modules.
The high modularity and the common core between a R&D framework and an operational forecast tool, is designed to minimise the time-to-market for new simulation routines. This is important in the current transition phase from lumped to distributed models in operational hydrology, since experience with operational distributed models is moderate, and subroutine improvements are likely to appear regularly.
Through the GDAL/OGR libraries, Enki is able to read and write most GIS formats, both for raster and for vector data. The list of available formats also includes meteorological file types like GRIB, HDF4/5 and NetCDF, making a range of complex data products available. GDAL/OGR also provides Enki with reprojection capabilities, enabling conversion between different coordinate systems and operation within any of these.
ENKI offers several routines for automatic calibration of hydrological models, including regional, multi-response calibration and evaluation by any measured variable. Enki also handles ensemble techniques and uncertainty estimation.