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Fall 2004
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The GIS-Based Swiss Water Information System Monitors Subterranean and Surface Waters

Swiss Agencies Promote GEWISS as a Gateway to Water Resources Data

By Hugo Aschwanden and Cornelia Renner, Swiss Federal Office for Water and Geology, Department of Water Resources Management

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GEWISScompass runs on the GIS expert client and the Intranet.

In Switzerland, the planning and implementation of water resources management measures are complex tasks because there are numerous interests requiring safeguarding, reconciliation, and balanced solutions. In addition, these tasks have become even more challenging since sustainability was incorporated into the new Swiss Federal Constitution: "Federation and cantons aim at achieving a long-term balanced relation between nature and its regeneration capacity on the one hand and the demands placed on it by man on the other hand." (Article 73)

While the accomplishment of this task calls for new methods and instruments, extensive data is already available on the condition of water bodies, their pollution, and the effects on their ecosystem, as well as on changes in their condition at a federal and cantonal level. To date, these valuable data sets, organized by numerous subsections of water protection and water resources management, were only made available in part to the Swiss public and to those affected and interested. To improve water management and related tasks, the Swiss Federal Office for Water and Geology (FOWG) and the Swiss Federal Office of Environment, Forests and Landscape (FOEFL) have increased efforts to promote the Swiss water information system GEWISS project. GEWISS is the Swiss national inventory system for the monitoring of subterranean and surface waters.

The basic objective is for FOWG and FOEFL to implement GEWISS as a gateway to water resources data to help solve the complex tasks of water resources management and water quality protection; make valuable data accessible to administration, research, and the public via an integrated user interface; provide nationwide overviews and analyses for Switzerland; and comply with national and international agreements on data exchange.

Taking on the Responsibility

To begin, FOWG took on the responsibility for the implementation of GEWISS as an IT solution. Shortly thereafter, Esri Geoinformatik GmbH Business Partner WASY GmbH (Berlin) was entrusted with the task of implementing its GEWISScompass software application as a major initial component of the overall system.

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The desktop user interface includes several desktop tools for editing data and queries.

One objective of GEWISScompass is to link the existing and new (spatial and nonspatial) data sets, along with capabilities allowing the data sets to be provided efficiently for requests, queries, analysis, and calculations. A further objective is to make this information available on a geodata server to all those involved in a uniform structure and by means of multiple and high-performance access paths—and to construct GEWISScompass in such a way that requests from national and international organizations can be answered.

Components of WASY's ArcGIS software-based ArcWFD ( were applied to GEWISScompass. The ArcWFD object model was optimized to meet the requirements of the European Water Framework Directive (WFD, see Component-based tools were built. Also, ArcWFD's design permits full and spatial imaging of surface water bodies and groundwater by providing the information required for river basin management and analysis. ArcWFD allows efficient processing of all river basin management and WFD-relevant tasks, such as planning expansions and new construction or renaturalization of water bodies, along with the maintenance of water bodies, facility operation, compilation of river basin management plans, and more.

The ArcWFD object model was developed in the Unified Modeling Language (UML) based on templates supplied with ArcGIS (ArcInfo). The implementation currently consists of approximately 200 classes, some of which form the topological water body network with approximately 1,800 attributes, including relations, value lists, and rules (such as default values, value ranges, and editing rules). ArcGIS 8 Desktop applications, such as ArcMap, work very efficiently with this object model without requiring customization.

In addition, the ArcWFD object model was adapted to fit GEWISS specific tasks, so it now contains approximately double the number of classes. All spatial data and attributes of the Swiss Water Information System are thus integrated and managed in an object-oriented geodatabase in ArcSDE for GEWISScompass.

The Implementation

In May 2003, an initial version of GEWISScompass was installed, administrators and test users were trained, and the data migration of existing spatial and thematic data into the GEWISS database was initiated. Since early 2004, GEWISScompass has been tested on both GIS expert clients as well as on the Intranet and contains data from 25 databases. The objective during the trial operation was to test the functionality and system behavior on hardware platforms on which the application is to be used productively at a later stage.

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Harmonization is required in places where disciplines overlap, for example, power plants where technicians deal with the safety of the dam, water pollution control, water resource management intervention on ecology, etc.

Most users access GEWISScompass via a standard Internet browser; however, experienced users accustomed to performing complex analyses can access files through specific ArcWFD client components, which are based on the ArcGIS Desktop ArcMap application. These components manage the user-related settings and provide complex analysis tools. These tools include a tool to manage themes and metadata; a watershed tool; a time series manager; a tool to explore and analyze water relevant information, such as that of incoming waters, watersheds, discharges, and measuring stations; and a tool that permits the recording, editing, query, and visualization of data along a water body.

The initial investment in a comprehensive data model has proven itself valuable, and making the information system based on uniform IT architecture available to both specialists and nonspecialist users works well. Also, from early on the standard functionalities of ArcMap permitted making initial analyses. In addition, the tools provided in ArcWFD meet the advanced demands of the water management industry.

Further implementation using GEWISScompass will involve data maintenance and harmonization, as well as the establishment of relationships between the objects, the water body network, and the watersheds. Also, emphasis shall be placed on the Internet presence, the technical expansion of the GEWISScompass application and the integration of data sets that were not available during the implementation stage. However, the costs for the provision of data, harmonization, troubleshooting, and the establishment of data maintenance and relationships that place particular challenges on GEWISS should not be underestimated.

For more information, contact Hugo Aschwanden, Swiss Federal Office for Water and Geology (e-mail:, Web:

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