esearch and Industry’ Award from the Institute for Risk Management

https://www.imdr.eu/

• The thesis proposes a method for evaluating runoff susceptibility maps using localized impact data, with an application in the railway context where information on the impacts of runoff on tracks, as well as track vulnerability, was collected.
• Generally, this work contributed to validating IRIP as an approach for mapping the risk of intense pluvial runoff.
• Specifically, the research demonstrated the operational relevance of IRIP for railway-related issues and helped define its potential modes of application in this context.

Surface runoff is the source of severe hazards such as floods, erosion or mudflows. Railways can disturb natural surface water flow path, which can generate accelerated deterioration of the infrastructure, or the destruction of railway elements, such as the roadbed or the embankments. The IRIP (French acronym) method ‘Indicator of Intense Pluvial Runoff’ (Lagadec et al., 2016b) allows mapping surface runoff through three maps, generation, transfer and accumulation. The IRIP method aims to be simple and reliable, in order to be used on all types of lands, without calibration stage. As for others surface runoff models, the IRIP method evaluation faces the lack of data.
However, evaluation is a crucial stage for the development of models. In the perspective of an operational use, or simply for the model development, it is essential to estimate the value and the reliability of the model outputs. The thesis objective is to provide an evaluation method using surface runoff impacts on railways (Lagadec et al., 2018b). Difficulties lie in the fact that data to be compared differ in terms of form and content. Moreover, the infrastructure vulnerability must be characterized. The proposed evaluation method is based on the computation of contingency tables and of verification indicators, together with detailed analysis of specific impacts (Braud et al., 2019). After an estimation of the IRIP method performance, further developments can be tested and evaluated thanks to the proposed evaluation method. Finally, maps comprehensibility is enhanced, while preserving satisfying performance scores (Lagadec, 2017).
By applying the IRIP method to operational contexts, it has been shown how the IRIP method can be used as a tool in expert appraisals. Different tasks of the risk management process have been studied such as risk analysis on railways, post-event investigation or the realisation of regulatory zonings (Lagadec et al., 2016a, 2018a). More generally, this thesis contributes to improve knowledge about surface runoff and provide methods for improving the risk management.

Funding

ANRT, CIFRE Contract with SNCF (2014-2017).

Publications and communications

• Braud, I., Lagadec, L.R., Moulin, L., Chazelle, B., Breil, P., 2019. Evaluation of a model for mapping intense pluvial runoff hazard using proxy data of runoff-related impacts. Application to the railway context, Natural Hazards and Earth System Sciences Discussion, 1-27, 10.5194/nhess-2019-208, 2019.
• Lagadec, L.-R., O. Benarima, P. Breil, B. Chazelle, & I. Braud. 2016a. Assessment of the susceptibility of transportation networks to intense surface runoff using the IRIP method of surface runoff susceptibility mapping, FLOODrisk 2016, 3rd European Conference on Flood Risk Management, Innovation, Implementation, Integration, 18 – 20 October 2016 - Lyon, France, E3S Web Conf., 7, 10005, 12 pp, http://dx.doi.org/10.1051/e3sconf/20160710005
• Lagadec, L.-R., P. Patrice, I. Braud, B. Chazelle, L. Moulin, J. Dehotin, E. Hauchard, & P. Breil. 2016b. Description and evaluation of a surface runoff susceptibility mapping method. Journal of Hydrology, 541 Part A, 495-509, http://dx.doi.org/10.1016/j.jhydrol.2016.05.049.
• Lagadec, L.R., Moulin, L., Chazelle, B., Braud, I., Breil, P., 2018a. A storm runoff mapping method for optimizing risk diagnoses of railway infrastructure, Safety Science, 110, partB, 253-267, https://doi.org/10.1016/j.ssci.2018.05.014 .
• Lagadec L-R, Braud I., Breil P., Moulin, L., Chazelle B., 2018b. Evaluation d’un outil de cartographique pour la gestion du ruissellement intense pluvial sur les voies ferrées, Congrès Lambda-Mu 21, Maitrise des Risques et transformation numérique : opportunités et menaces, 16-18 Octobre 2018, Reims, France, 9 pp.

Cite the thesis

Lilly-Rose Lagadec. Evaluation et développement de la méthode IRIP de cartographie du ruissellement. Application au contexte ferroviaire. Sciences de la Terre. Université Grenoble Alpes, 2017. Français. ⟨NNT : 2017GREAU039⟩. ⟨tel-02607053v2⟩

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