Topographical elements linked to runoff axes (cuvettes and embankments) on Rennes Métropole

Description

This layer complements the layer of runoff axes on Rennes Métropole (UUID = e0fa5c09-ee44-46ff-a068-b6dada575c9f) by topographic analysis. As part of the runoff study currently being conducted by Rennes Métropole (2023-2025), a first analysis of the hydraulic functioning of the territory was carried out at the global scale of its territory. On the basis of the forms of the natural terrain, the analysis made it possible to identify the topographical elements linked to the following runoff axes: => Low-point basin areas/no outlets where water will tend to accumulate naturally; Only basins (or topographic depressions) with a depth of less than 10 m, an area of more than 250 m2, a depth of more than 20 cm are displayed. These display thresholds are based on physical criteria: they correspond to the average surface area of a plot in an urbanised sector and to the height of a step or sidewalk. The troughs displayed are only troughs that cross a runoff axis, so they have dynamic operation with potentially significant flow velocities. => Structural embankments, in particular road and rail infrastructure, which constitute obstacles to the natural flow of water and can therefore generate artificial accumulation zones. Limits on the use of the data: The topographic elements (cuvettes and embankments) mapped are only those that cross (within a certain radius) a runoff axis. The entire volume of a basin is not necessarily mobilized in the current state of development, but these are areas that could be flooded as a priority in the event of land take in the vicinity. Thus, it is in all cases essential to compare these analyses with the reality of the territory and in particular with the historical observations recorded. Rather, it is an invitation to deepen the knowledge of the risks on the sectors at stake. For more information, see the metadata below: [https://public.sig.rennesmetropole.fr/geonetwork/srv/fre/catalog.search#/metadata/00d2d4dc-6881-4355-a5d3-b1a25b733e7a](00d2d4dc-6881-4355-a5d3-b1a25b733e7a) [Click here to download (OGC GeoPackage - 20 MB)](https://public.sig.rennesmetropole.fr/ressources/donnees/ocsol_mode/cuvette_remblai.gpkg)

Resources

Name Format Description Link
8 https://www.data.gouv.fr/api/1/datasets/r/0b0ae503-9103-4d1d-ad8d-5bdf6f69d071
57 https://www.data.gouv.fr/api/1/datasets/r/d4acaef9-144c-4cba-9975-1002cc04dadb
23 https://www.data.gouv.fr/api/1/datasets/r/98c41e93-576e-490f-b57e-87e202da444d
23 https://www.data.gouv.fr/api/1/datasets/r/9080a08a-f406-48f4-a3f6-b8854a5acb53

Tags

  • environnement
  • classification-de-lusage-des-sols

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