General Database for Ground Water Site Information by Jean-Raynald de Dreuzy 1 , Jacques Bodin 3 , Herve ´ Le Grand 4 , Philippe Davy 2 , Damien Boulanger 4 , Annick Battais 2 , Olivier Bour 2 , Philippe Gouze 5 , and Gilles Porel 3 Abstract In most cases, analysis and modeling of flow and transport dynamics in ground water systems require long- term, high-quality, and multisource data sets. This paper discusses the structure of a multisite database (the H1 database) developed within the scope of the ERO program (French Environmental Research Observatory, http:// www.ore.fr). The database provides an interface between field experimentalists and modelers, which can be used on a daily basis. The database structure enables the storage of a large number of data and data types collected from a given site or multiple-site network. The database is well suited to the integration, backup, and retrieval of data for flow and transport modeling in heterogeneous aquifers. It relies on the definition of standards and uses a templated structure, such that any type of geolocalized data obtained from wells, hydrological stations, and meteorological stations can be handled. New types of platforms other than wells, hydrological stations, and mete- orological stations, and new types of experiments and/or parameters could easily be added without modifying the database structure. Thus, we propose that the database structure could be used as a template for designing data- bases for complex sites. An example application is the H1 database, which gathers data collected from a network of hydrogeological sites associated with the French Environmental Research Observatory. Introduction For the past 20 years, many ground water databases have been developed (see, e.g., Barazzuoli et al. 1999; Newell et al. 1990; Seyfried et al. 2001; van der Lee and Lomenech 2004). One of the main objectives of databases is to promote long-term monitoring and backup of ground water data, which is a basic requirement for many hydro- geological studies. Despite the broad range of available databases, few are suitable for modeling purposes at the field scale, i.e., for studies dedicated to aquifer and/or process characterization. In hydrogeology, there is a real need to develop databases that gather together a large number of different types of data collected at specific geographical sites. Site-oriented ground water databases are the natural interface between long-term recording and experiments on the one hand and models on the other hand. This paper discusses the structure of a multisite data- base (the H1 database) that has been developed within the scope of the ERO program (French Environmental Research Observatory, http://www.ore.fr). The so-called H1 observatory is a national network of hydrogeological sites in France. Today, H1 comprises three hydrogeological sites (Ploemeur, Poitiers, Cadar- ache), which are complementary in terms of geology, aquifer exploitation, and scientific research objectives. The goal of H1 is both to improve the understanding of the water cycle and transport of chemical species in het- erogeneous aquifers, and to provide high-quality (well documented) data for testing predictive models and for developing ground water modeling tools. The latter goal makes the development of a database one of the crucial tasks of the H1 observatory. Of course, because the H1 database relates to hydrogeological sites, the main data source is boreholes. Borehole data can be subdivided 1 Corresponding author: Ge ´osciences Rennes (UMR CNRS 4661) Campus de Beaulieu, Universite ´ de Rennes 1, 35042 Rennes Ce ´dex, France; jean-raynald.de-dreuzy@univ-rennes1.fr 2 Ge ´osciences Rennes (UMR CNRS 4661) Campus de Beaulieu, Universite ´ de Rennes 1, 35042 Rennes Ce ´dex, France. 3 Hydrasa (UMR CNRS 6532) Universite ´ de Poitiers, 40, Avenue du Recteur Pineau, 86022 Poitiers Ce ´dex, France. 4 Me ´dias France, BPi 2102 18, Avenue Edouard Belin, 31401 Toulouse Cedex 9, France. 5 UMR 5568, Laboratoire de Tectonophysique, ISTEEM. CNRS Universite ´ de Montpellier 2. Montpellier, France. Received November 2005, accepted February 2006. Copyright ª 2006 The Author(s) Journal compilation ª 2006 National Ground Water Association. doi: 10.1111/j.1745-6584.2006.00220.x Vol. 44, No. 5—GROUND WATER—September–October 2006 (pages 743–748) 743