In collaboration with the University of Birmingham and the Environment Agency, BGS have developed the ZOOM group of numerical groundwater models. This group consists of the saturated groundwater flow model ZOOMQ3D, the advective transport particle – tracking code ZOOPT and the distributed recharge model, ZOODRM. Each of these models has been developed using object-oriented techniques, a programming approach commonly applied in commercial software development but only relatively recently adopted in numerical modelling for scientific analysis.

Most existing groundwater models have been developed using older programming techniques, which tend to produce codes with complex and inflexible structures that are difficult to maintain and modify. This inflexibility forces hydrogeological modellers to fit their conceptual model of a groundwater system to that of the code being used. This can require the simplification of both the conceptual and numerical models. In contrast, the object-oriented approach being developed by the project partners aims to produce models with structures that closely represent those of conceptual groundwater models. This is achieved by developing objects, the building blocks of an object-oriented model, that represent individual features of a system, for example abstraction boreholes, rivers or geological formations such as river valley gravels.

The aim of the continuing research is to develop a modelling system based on a framework of objects that can be modified to better represent different hydrogeological settings. This will involve the development of both novel numerical techniques and objects that represent geological units. The use of objects will also simplify the linkage of the code to other types of models, for example surface water models. A number of advances have been made during the development of the existing code ZOOMQ3D, in particular the implementation of a local grid refinement method to rapidly increase the resolution of the mesh in specific areas of interest.

One objective of the research is now to develop objects that represent geological or hydrogeological volumes. These should link together to produce a three-dimensional groundwater flow model that closely represents that of the geological model on which it is built. It is envisaged that this development will benefit significantly by its linkage with the geological modelling package GSI3D. If you require any further information about the ZOOM models please contact zoom@bgs.ac.uk.

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