GIS for Coastal Zone Management - Chapter 19

CHAPTER NINETEEN A Territorial Information System (TIS) for the Management of the Seine Estuary – Environmental and Management Applications Jean-Côme Bourcier 19.1 INTRODUCTION Located at the geographic, sociological, economic, and environmental convergence of multiple interest groups, the estuary of the Seine (Normandy, France – Figure 19.1) presents itself as a coastal zone subject to divergent, if not contradictory, anthropogenic pressures. In fact, its position vis-à-vis its ecosystems gives it rare and specific functions and its location within geographic space confers strategic advantage. The urbanisation and level of primary industry of the region must develop in directions that respect an ecological heritage, and an exceptional landscape, that is subject to the attention of local communities as well as local, state and European levels of administration. Furthermore, the existence of various pollutants, risks from technological hazards, the exploitation of natural resources, an upstream/downstream divide, a disparity between left and right banks, and multiple activities, etc., are just some of the key issues in this unique space. In this context, geographical information systems (GIS) present a wealth of applications as tools capable of collecting, harmonising and analysing data about the estuary coastline in order to monitor the health of the region and provide summary information as an aid to decision-making. Harnessing these technological, methodological, and operational tools enables coastal management problems to be defined and resolved in an holistic and consensual manner. They could also lead to a new approach to management and a remediation, by providing a better understanding of coastal processes, functioning and change; an approach more attuned to the natural and human complexities of a geographic space that encompasses all levels of organisation, and which has set sustainable development as primary goal. These distinguishing features justify the establishment and use of a GIS specific to the Seine estuary within the CIRTAI laboratory at the University of © 2005 by CRC Press LLC Le Havre (UMR 6063 CNRS – Research`s group CIRTAI). More specifically, it consists of a territorial information system (TIS) tied to a multidisciplinary and multi-thematic, geographically referenced database designed to improve understanding of the processes and functioning of the estuary in order to support operational and participatory management practices. Within the range of spatially referenced information systems, (Prélaz-Droux, 1995), this territorial information system sits mid-way between the two end-points of land information system and geographical information system as defined by the author: it exceeds the institutional limits of a land information system, and applies the potential of a GIS in its ability to support development of land and environment in a complex geographic space that requires management at multiple scales and involving multiple actors. The aim of this article is to demonstrate a particular application of the TIS, as an observatory of the natural heritage of the Seine estuary. Within this application, different levels of information have been integrated and analysed in order to provide qualitative and quantitative assessments of this heritage by means of territorial diagnostics. Figure 19.1 The Seine estuary (Normandy, France). 19.2 ON THE NEED FOR AN OBSERVATORY OF THE NATURAL HERITAGE IN THE SEINE ESTUARY As a meeting point for terrestrial, fluvial and marine environments, the Seine estuary integrates a number of biologically productive and varied ecosystems. It is © 2005 by CRC Press LLC an integral element in the routeway for many species of migrating birds and provides shelter and nutrients for fisheries and shellfish farming as well as for certain invasive species. The estuary basin is characterised by the juxtaposition of alluvial plains and calcareous plateaux, giving rise to an extraordinarily diverse range of humid-zone landscape types that act as sponges and filter-cleaners for the environment. Nowadays, the natural heritage of this estuary is subject to the impacts of numerous activities and processes at the local scale (industrialisation, urbanisation, agriculture, resource exploitation) as well as nationally (it is the outlet of a drainage basin within whose borders is found 30% of the French population and 40% of the national economic activity). This convergence of interests, and the conflicts that arise, raises the problem of how to conserve natural spaces whose resources are limited and whose equilibrium is fragile. Management of this territory must therefore ensure balanced development, taking into account both scientific data and socio-economic factors (Chappuis, 1993), at a scale that is essentially local but which also has national and international elements (Bailly, 1995). Every stage in the process involves nature and the landscape, and it is often necessary to draw on a complete inventory of the natural and landscape heritage in order to steer decision-making in appropriate directions whenever choices present themselves. In order to address these requirements, the Seine Estuary TIS acts as an observatory of natural heritage, and an intelligent tool for providing territorial and environmental indicators needed to manage this unique coastal system. GIS offers technologies with potential for better planning, management and analysis of our environment (Bryant, 1993); for tackling the integrated, holistic and rational management of space; for pooling necessary information; and for overcoming institutional limitations, to allow all levels of environmental organisation (hydrological systems, landscape systems, drainage basins, etc.) to be taken equally into account. The objective is to make available to environmental managers and decision-makers a suite of key indicators that will allow better understanding of disparities between left and right banks of the river, conditions of flood and low water, competition and compatibilities of estuarine biota, etc., and ultimately allow the delimitation of zones of strong environmental vulnerability. This will also help bridge the gaps between scientific research and real-world practice and, more precisely, between those scientists, technicians, professionals, and politicians who are involved in strategic and political decision-making. The territorial information system for the Seine estuary aims to bring the many facets of the same geographic reality into a common framework. Thus organised and structured, all available data for a given location may be integrated as part of a single analysis, in order to better define environmental objectives, and to provide support for decisions relating to territorial planning and management within the estuary. © 2005 by CRC Press LLC 19.3 FROM DATA COLLECTION TO DEVELOPMENT OF ENVIRONMENTAL DIAGNOSTICS This TIS for the Seine estuary exploits a multi-source and multi-thematic geographically referenced database, presently consisting of more than 80 layers of data in vector format, standardised on the Lambert conformal conic projection and georeferenced on the Lambert zone 1 coordinate system (the local system for the north of France). Data in raster format are used to provide rapid enrichment and updating of the database, according to immediate needs. These data layers are all subject to a number of quality-control parameters (Laurini and Milleret-Raffort, 1993) including accuracy, precision, and timeliness (Rouet, 1991), and each layer is the subject of a file of metadata (Bourcier et al., 1998) to ensure that it is used appropriately and optimally. A dynamic link has been developed, so that the metadata may be consulted directly via the user interface of the GIS software. The operational use of the TIS requires, inter alia, data to be updated regularly, since they describe a territory that is subject to strong spatio-temporal evolution. Data relating to the natural heritage of the Seine Estuary are collected on a regular basis by various groups: the regional Ministry of Environment for Upper and Lower Normandy, the Department of Hunting, an organisation for the conservation of wetlands, the Regional Nature Park of Brittany, Nature Park, etc. This demands an effective partnership, in order to respond to the specified quality criteria. Initially, exchange of these data was via hard-copy paper media (maps, cadastral plans, etc.), which implied heavy, time-consuming digitisation overheads. More recently, all the data-providing partners have opted for the advantages of digital technologies (GIS platforms, CAD, computer-assisted cartography), which has enabled much more efficient implementation of the system. An environmental geodatabase is by definition multidisciplinary and multi-territorial; its quality and relevance depend on, among other factors, the abilities of the GIS team to manage interdisciplinary conflict, institutional compartmentalisation and protectionism, hierarchical management “pyramids” and cultures of regulation, etc.; and especially possessive attitudes and the equation of information with power, leading to a reluctance among some players to share information with others. 19.3.1 Environmental heritage diagnostics in the Seine Estuary As has been discussed above, all management practices have environmental implications, and therefore require access to a complete inventory of the natural heritage. This essential knowledge of the natural resources of a region needs no further justification. The natural heritage value of the Seine estuary is recognised through the implementation of a number of statutory instruments of national or European origin: the Ecological Fauna and Flora Inventory (“ZNIEFF”), Nature Reserve, Special Areas of Conservation (SACs), Biotope conservation, etc. To these are added other protective measures, such as the purchase of land. © 2005 by CRC Press LLC It seems evident that this accumulation of regulations makes the direction of management projects even more difficult, especially since many of these provisions lack clarity, are obsolete, are contradictory and of uncertain relevance, or are imprecise and subject to multiple, subjective interpretations. Figure 19.2 Spatial concentration of environmental conservation in the Seine estuary. Superimposition of all these layers demonstrates visibly the multiplicity of initiatives and regulatory measures that currently apply to this territory. We may also note several important geographical overlaps between these various measures, rendering their representation in cartographic form particularly difficult. Overall, such a representation implicitly demonstrates the high heritage value of this estuary, but the resulting legislative overload demonstrates clearly the need for harmonization of French Environmental law. French estuaries present a major challenge for the law, which must find ways to address their hybrid character and their multifunctional nature. Analysis of the legal treatment accorded these spaces demonstrates the weak acknowledgement in national law of their distinctive nature and, indeed, a strong tendency to promote their development, despite the accumulated knowledge of their ecological interest and their vulnerability (Auger and Verrel, 1998). © 2005 by CRC Press LLC ... - tailieumienphi.vn