Mapping land use change in a "river city".

1. Mapping land use change in a "river city". An opportunity for designing a comparative interdisciplinary approach and discussing a common conceptual framework in LTER Thierry Joliveau, Jean-Paul Bravard, Bernard Dupuis (1) Charles Redman, Cathryn Meegan (2) (1) CNRS UMR 5600. France (2) Centre for Environmental Studies. Arizona State University

2. The Lyon Y project • Aim • a geo-historical analysis of the interactions between society and environment in the Rhône and Saône alluvial corridor of Lyon • Context • A “Workshop site” of the “Zone Atelier du Rhône” (ZABR), • supports collaborative interdisciplinary research • is intended to provide historical data and information needed by the public and decision-makers to understand the long-term dynamics of the fluvial environment. • First application • a historical and spatial approach of the risk of flood since 1840

3. Location of the Y Lyon

4. Lyon Metropolitan area

5. Temporal GIS as a collaborative tool • A support for • interdisciplinary research, • multi-field workshops with scientists, decision-makers, stakeholders, public • 3 geographical databases Central area River tract Metropolitan area

6. GIS Features • General features • Based on GIS capacities to integrate multi-source and multi-scale data • Long term GIS Project (several years) • Geo-referenced to the geographical database of Grand Lyon administration. • Specific methodological approach • Integration of historical maps and data • Temporal dimension of the GIS • Multi-scale articulation (coherence, compatibility) • Collaborative and interdisciplinary context • Metadata, means of diffusion … Historical maps image database

7. Mapping land use in historical and multi-scale perspective • Historical • Stability of LULC typologies definitions through time? • Same name, different realities ? • Ex.: industry, recreational areas • Multiscale • Center area : • Categories of buildings • River tract : • Categories of land use according to vulnerability analysis • Metropolitan area : • Generalized land cover types

8. Metropolitan scale • Objective: analyze the long term urban dynamic • Scale of use: between 1:50,000 and 1:100,000 • Error of precision in the localization: 75 m • Minimal area of a surface object: 2,5 ha • LULC relating objects: • Main communication network (roads, railways...) • Generalised land use areas • Census zones

9. River tract scale • Objective: understand the interactions between society and environment in relation to the river • Scale of use: between 1:20,000 and 1:50,000 • Error of precision in the localization: 25 m • Minimal area of a surface object: 2500 m² • LULC relating objects: • Roads and main streets network • Medium scale LULC areas (ecological assessment, flood vulnerability analysis) • Land use plans and regulations • Objects affecting the geometry of the flood plain

10. Center area scale • Objective: confront flood and urbanisation dynamics in the middle of the 19th Century • Scale of use: between 1:10,000 and 1:20,000 • Error of precision in the localization: 15 m • Minimal area of a surface object: 1000 m² • LULC relating objects: • Buildings • Blocks • Streets

11. Progress report • Model/prototype of integration of historical data in Y Lyon • Methodological approach of historical and spatial analysis of the risk of flood • Inventory of the historical maps and plans available • Methodological phase for analysing the changes in land use at the metropolitan scale (1840-2000)

12. Land use change in the Lyon metropolitan area since 1840 • General aim • Mapping the global urban dynamic to understand the driving forces of river tract evolution • Specific aim • Develop a general method for analyzing land use change in an urban context • LTER Cooperation • Exploratory work realized in collaboration with the Phoenix LTER : • methodological analysis • comparison of 1902 and 1980 topographic maps

13. Previous works • Projects • USGS Urban Dynamics Research Program • Systematic approach : San Francisco Bay Region, Detroit River Corridor, and Philadelphia-Wilmington … • Phoenix Historic generalized land use project • LTER approach • Philadelphia and Cologne Sinton’s projects • Delaware, Cologne • Using old European topographical maps

14. Metropolitan scale LULC Database • General questions • Definition of the LULC categories according to the objective of the project and the information available • Stability of categories • “Objective categories” : vineyard and orchards, forest, built-up areas and water; • Integrating information from very heterogeneous maps in scale and semiology • Managing temporal discordances • Specific Y Lyon Project questions • Compatibility of the data between different scales • Elaboration of a topographic maps images database  on-screen digitalization

15. Comparing techniques • Techniques : polygon digitalization, grid or point selection, • Evaluation factors : rapidity, facility, accuracy, limited subjectivity • Point digitalization method adopted

16. Preliminary results : 1902 built-up areas

17. Preliminary results, 1980 map built-up areas

18. Preliminary results, comparisons

19. Preliminary results : technical tasks • Improve the formalization of protocols • Precise category definitions and status : • Gardens • Transportation areas • Squares, urban parks status • …

20. Methodological questions • Map semiology bias (roads width) • Land cover vs. land use • Ex : Large opened areas (airports, military zones, outskirts commercial centers) • Utilization of other topographic map data : • Wetland, ponds, swamps, edges … • Category definitions depends on the goals of the research : • Urban sprawl analysis ? • Geographical analysis of urbanization trends and forms ? • Global ecological evaluation of Land Use change ? • LULC Change analysis methodology options determine many aspects of a research project

21. Interest of a historical and generalized LULC database • Y Lyon team level • Formalization of the urban sprawl dynamics • Spatial frame for analysing the evolution of interactions between the city and the river corridor • Quantification of the built-up areas • Modelling the spatial diffusion of urbanisation • ZABR level • Providing historical data and information needed by the public and decision-makers to understand the long-term dynamics of the fluvial environment. • Comparing relations between urban growth and river tracts in different Rhone Valley cities • Analyzing the ecological effect of land use changes (fragmentation, disconnections, disturbance, …)

22. LTER Approach • In search of a more complete and comprehensive model of Human-Ecosystem Interaction, Grimm, Grove, Picket, Redman (2000)

23. Human-ecosystem Interaction • In a Zone Atelier, an interdisciplinary research involving hydrologists, ecologists, engineers, geographers, historians and sociologists can’t avoid a debate on the Human-ecosystem Interaction • The new general orientation of French Zone Ateliers, which plans to organise the research on a common conceptual base, the anthroposystem, requires discussion of such a conceptual framework

24. A central parameter • Land use appears as a central factor of the conceptual models allowing integration of the social and ecological systems in an urban environment Grimm, Grove and al. (2000)

25. Interest of an historical LULC database • Despite (or because) of its (false) simplicity, LULC mapping could be the first step to a conceptual exchange about Urban Ecological Systems in an interdisciplinary context • The history of LULC change is a key to the understanding of human activities dynamics • The comparative approach proposed could facilitate the common conceptual work which is needed between LTER teams.

26. Conclusion • An harmonized LULC mapping method could (simply) contribute to the cooperation between different urban LTER projects • a comparative approach of relations between urban growth and river tracts • a conceptual framework to studies of urban ecological systems