ABSTRACT
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
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.
