GIS for Coastal Zone Management - Chapter 11

CHAPTER ELEVEN Towards an Institutional GIS for the Iroise Sea (France) Françoise Gourmelon and Iwan Le Berre 11.1 INTRODUCTION As far as coastal zones are concerned, many challenges faced by the scientific community and policy makers, planners and managers justify adoption of a transdisciplinary approach based on bio-chemical, geophysical and socio-economical factors (Burbridge and Humphrey, 1999). GIS are well-established computer-based systems for storing, retrieving, analysing, modelling and visualising the vast amounts of spatial data that may be collected by several providers (Fabbri, 1998). Nevertheless, the implementation of a coastal database is a complex process which requires institutional support to guarantee the multidisciplinary approach, the sustainability of the project in terms of raising funds and human resources, and to promote relationships with other institutions working on the same area (De Sède and Thiérault, 1996). The major pollution caused by the Erika disaster, coupled with the catastrophic storms which reached the Atlantic coastal zone at the end of 1999, has led the French authorities to propose creation of a national coastal GIS. The implementation of such a project is complex, witnessed by the lack of any decision about which reference geographical data for the coastal zone to adopt (Allain et al., 2000). In fact, coastal data are scattered among many organisations. They are produced for lots of purposes and therefore are available at various scales, typologies and formats. In spite of these difficult conditions, there are a number of smaller, independent GIS projects at work on the French coastal zone (ENR/OELM, 2000; Guillaumont and Durand, 2000). This contribution describes the GIS implemented by Géosystèmes laboratory (CNRS, European Institute for Marine Studies) on the coastal zone of Finistère (western Brittany, see Figure 11.1) during the last ten years. In the beginning, the GIS was conceived as a support tool for monitoring and managing the Biosphere Reserve of Iroise, but today, it also serves as a powerful tool for carrying on integrated research on the coastal zone of the Iroise Sea, especially within the framework of the European Institute for Marine Studies (Institut Universitaire Européen de la Mer, IUEM). This latter institute brings together a number of © 2005 by CRC Press LLC separate marine research teams from the University of Western Brittany, Brest, dealing respectively with oceanography, geology, biology, chemistry, geography, economy and law. The development from a GIS dedicated to scientific applications towards an institutional support is described below. Figure 11.1 Study area 11.2 THE DATABASES Nowadays the GIS supports two complementary databases, called SIGouessant and BIGIroise, that were originally developed with separate objectives and data (see Figure 11.2). The SIGouessant database deals with the Mer d’Iroise Biosphere Reserve at a local scale. The biosphere reserve label is allocated to representative terrestrial and coastal areas by the UNESCO Man and Biosphere (MAB) programme. The conception of such an area is based on three main functions: conservation of biodiversity and landscapes; sustainable use in regional units; and logistic support for research, monitoring, education, information and involvement of the local population. In this context, many thematic studies have been performed on the Mer d’Iroise Biosphere Reserve to increase knowledge of dynamic terrestrial and marine processes, and to study the aftermath of human activity such as tourism, management and fishing on biodiversity. The objectives are to provide a basis for land management recommendations as well as for wildlife management © 2005 by CRC Press LLC programmes. The SIGouessant database has been developed since 1990 as a support to the long term ecosystemic approach, and to provide data for scientific and management investigations (Gourmelon et al., 1995). The geographic reference data is provided by orthophotographs produced by the French National Geographical Institute (IGN - Institut Géographique National). The thematic layers describe physical, natural and social parameters with the same classification systems and scales, collected at various dates thanks to continued monitoring. Figure 11.2 Database organisation The BIGIroise database is an extension of SIGouessant to the whole coastal area of the Iroise Sea. Its initial aims were to produce a synthetic environmental © 2005 by CRC Press LLC mapping through combination of multiple data sets available for the coastal zone (Le Berre et al., 2000). The database uses marine geographical information produced by the French hydrographic service (SHOM – Service Hydrographique et Océanographique de la Marine), and is built up according to the environmental planning methods developed and proposed by the Unesco MAB committee (Journaux, 1985). After the collection of existing digital data, and the digitisation of other data sources (atlases, maps, etc.), 34 thematic layers, concerning physical, biological and socio-economical parameters for marine and terrestrial areas of the Iroise Sea have been integrated in the GIS (see Figure 11.2). After ten years of functioning, this GIS has become an adopted tool for data inventory, environmental analysis and decision-making, which have been described by Crain and Mc Donald (1984) as three development stages of a GIS. 11.3 OVERVIEW OF IROISE GIS APPLICATIONS 11.3.1 State of the knowledge After the development of a set of tools for data processing and analysis, using techniques such as association, combination and generalisation, the resulting databases have been used to compile a baseline assessment of the state of knowledge regarding the marine and terrestrial environments of the Iroise coastal area. This has allowed the production of an atlas for public communication (Gourmelon et al., 1995), and the creation of a synthetic map showing the potential conflicts of interests in the Iroise Sea (Le Berre, 1997). These documents are used to support discussions among the stakeholders. However, this inventory of existing knowledge also shows that the quality of available data is heterogeneous  especially in terms of exhaustiveness and age  though strong efforts to collect and structure data on the Iroise Sea have been made by a number of scientific and institutional organisations. One of the main difficulties lies on the compatibility of marine and terrestrial geographical reference data. Although the compatibility is essential for database coherence, we are still waiting for a national consensus (Alain et al., 2000) on this issue. Other difficulties come from the lack of knowledge about the marine environment. The structure and the functioning of the Iroise Sea ecosystem remains barely understood. Moreover, except for some legal aspects, scarcely any geographical information dealing with human activities is available. GIS offers many functions that may be used to bypass these problems: For example, the database can help define sampling strategies to be used for collecting additional marine biological data; and it may also provide relevant data for the implementation of theoretical models of ecological population distribution, based on the applications developed for the US Gap Analysis project (Davis et al., 1990). The population models used for Iroise Sea are based on physical parameters such as bathymetry, sedimentology, and hydrodynamic features (marine currents and waves) and have been tested successfully on seaweeds and on the bottlenose dolphin (Tursiops truncatus, see the next section, below). Furthermore, integration © 2005 by CRC Press LLC with remote sensing allows the production of synoptic and multi-temporal data that are particularly useful for marine studies, because of the variety of the sensors used for recording parameters such as water colour, sea surface temperature, shore morphology, etc. (Van Zuidam et al., 1998). 11.3.2 Environmental issues GIS is now widely used for applications relating to terrestrial studies and management issues. In landscape ecology especially, the capabilities of GIS are successfully used to perform spatial and statistical analysis of many environmental components, and for modelling real-world processes (Haines-Young et al., 1993). In the islands and the islets of Iroise Sea, many similar GIS applications are concerned with exploring relationships between vegetation and land-cover changes, fauna (rabbits and nesting birds) and human activities. For example, land- cover and land-use changes of Ushant island over a 150-year timeframe have been studied, using field studies, aerial photographs and the 19th Century land registry (Gourmelon et al., 2001) as primary sources of data. Over this period, the island underwent a drastic transformation from rural landscape to extensive shrubland. Only traditional extensive sheep breeding is actually maintained. Within a GIS analysis, the relationships between sheep grazing and land-cover have been established, and scenarios of land-cover potential related to changes in the intensity of sheep grazing produced. The scientific results have provided an objective framework for further assessment of fallow land management. Figure 11.3 Investigating factors influencing spatio-temporal distribution of bottlenose dolphin (Tursiops truncatus) In contrast to these successes on-shore, the implementation of GIS is more difficult in the marine environment due to the peculiarities of maritime space-time © 2005 by CRC Press LLC ... - tailieumienphi.vn