| Title: |
Urban cultivated terraces and rainfall runoff reduction: a case study from Lyon. ; Les terrasses agricoles urbaines et la réduction du ruissellement pluvial : un cas d’étude lyonnais. |
| Authors: |
Breil, Pascal; Ben-Salem, Wejdane; Courapied, Fanny; Gonzalez-Sosa, Enriqué |
| Contributors: |
RiverLy - Fonctionnement des hydrosystèmes (RiverLy); Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE); Universidad Autónoma de Querétaro (UAQ) |
| Source: |
Novatech 2023 : 11e Conférence internationale sur l'eau dans la ville ; https://hal.science/hal-04176878 ; Novatech 2023 : 11e Conférence internationale sur l'eau dans la ville, Jul 2023, Lyon, France |
| Publisher Information: |
CCSD |
| Publication Year: |
2023 |
| Collection: |
Institut National de la Recherche Agronomique: ProdINRA |
| Subject Terms: |
intense rainfall; cultivated terraces; drought; urban runoff; climate change; changement climatique; pluie intense; ruissellement urbain; sécheresse; terrasses cultivées; [SDE]Environmental Sciences; [SPI.PLASMA]Engineering Sciences [physics]/Plasmas |
| Subject Geographic: |
Lyon; France |
| Description: |
International audience ; The city of Lyon has a varied topography with its two hills of Fourvière and Croix Rousse with respectively a difference in level of 208 and 90 meters in relation to the river Saône. These configurations are known for their instability in case of heavy rains or poor drainage. Thus, 30 ground movements were recorded in 1983 following an exceptionally rainy and stormy beginning of the year. Climate change now poses the question of stormwater conservation in periods of prolonged drought interspersed with intense storm events. In this context, the "permeable city" objectives of the Lyon metropolis aim to "desoak" 400 ha by 2026 and to disconnect stormwater networks, in order to initiate a paradigm shift in urban runoff management. Developing both the prevention of flooding by intense urban runoff and reducing the impact on watercourses falls within the scope of the GEMAPI competence, which allows the financing of these actions. This study evaluates the role of cultivated terraces in an urban context on the reduction of runoff and water conservation. The runoff of the allotment gardens of the Fort de Loyasse (70 plots, 2.8 ha) is compared by modeling to a situation without terraces with a grassy cover. It is shown for a 100-year rainfall a reduction of 75% of the runoff volume, a delay of 40 minutes of the peak of runoff, a reduction of 30% of this peak, and a remanence of the humidity in the terraces. ; La ville de Lyon présente une topographie variée avec ses deux collines de Fourvière et de la Croix Rousse avec respectivement un dénivelé de 208 et 90 mètres par rapport à la rivière Saône. Ces configurations sont connues pour leur instabilité en cas de fortes pluies ou d’un mauvais drainage. Ainsi 30 mouvements de terrain ont été répertoriés en 1983 suite à un début d’année exceptionnellement pluvieux et orageux. Les pentes urbanisées renforcent le ruissellement pluvial dont le drainage est facilité jusqu’au fleuve mais avec un impact lié aux eaux polluées des réseaux pluvial et unitaire. ... |
| Document Type: |
conference object |
| Language: |
French |
| Availability: |
https://hal.science/hal-04176878; https://hal.science/hal-04176878v1/document; https://hal.science/hal-04176878v1/file/D3_NJCIS4W_Breil.pdf |
| Rights: |
https://about.hal.science/hal-authorisation-v1/ ; info:eu-repo/semantics/OpenAccess |
| Accession Number: |
edsbas.2A00C966 |
| Database: |
BASE |