Project Q13: Quantifying changes in exposure, vulnerabilities and risks of pluvial and fluvial floods

Timescale: Oct. 2021 – Sept. 2024

Supervisors:

Prof. Annegret Thieken, University of Potsdam

PD Maik Heistermann, University of Potsdam

Dr. Tobias Sieg, University of Potsdam

Prof. Fabrice Cotton, GFZ Potsdam & University of Potsdam

Description

Increasing flood losses have often been attributed to changes in exposure, e.g. extended built-up areas and increasing wealth in flood-prone regions (Barredo 2009; 2010), or changes in vulnerability: after a long absent of floods, people’s preparedness is low, while there’s a steep increase in the uptake of property-level mitigation and preparedness measures after floods (e.g. Bubeck et al. 2012; Kienzler et al. 2015) resulting in an overall lower level of damage and risk (e.g., Thieken et al. 2016b; Kreibich et al. 2017). While a lot of work has already been done on fluvial floods, comparatively little is known about such developments in the context of pluvial floods (also called urban floods, in hilly regions they may result in flash floods). In addition, exposure is an under-researched element of the risk equation. Therefore, this project addresses these two research gaps.

While the project Q3 focussed on the quantification of changes in vulnerability of residents (susceptibility) and their motivation to implement precautionary measures in respect to fluvial and pluvial floods (Laudan et al. 2019), the project P7 is aimed to develop a dynamic model that delivers projections of precautionary behaviour and that can be integrated into a flood loss model. This project (Q13) aims to quantify changes in exposure and to combine these with changes in vulnerability of flood-prone residents. Together with the underlying hazard scenarios this will lead to new risk scenarios and metrics. The project consists of three steps:

1. Quantify (past) changes in flood exposure on the basis of different data sets (HILDA; CORINE Land Cover, Global Human Settlement Project, Copernicus Urban Atlas) and assess their suitability for flood exposure assessments and changes in exposure. Several case studies that cover different flood types and different spatial scales are to be considered, e.g. reaches along the Rhine river and the Mulde river, the cities of Bremen, Remscheid or Solingen and maybe the North Sea Coast in Lower Saxony.
2. Calibrate and validate a land use model (e.g., DynaCLUE, see Cammerer et al. 2013) to selected case study areas (from step 1). Run the model until 2050 and develop a disaggregation method to transform the meso-scale land use pattern (raster information) to the micro-scale (e.g. to single buildings). For the latter, current patterns of buildings in urban areas have to be identified and transformed into typical patterns, e.g., on the basis of OpenStreetMap Data. Model results should be discussed with local or regional planners to allow a verification of the outputs.
3. Update and validate the dynamic loss model from P7 (and an associated PhD) by up-to-date information on the state of precaution and preparedness among residents in flood-prone areas and combine changes in exposure and vulnerability to assess changes in risk. Changes in vulnerability are assumed to be highly dependent on the actual occurrence of flood events and the fluctuation within in flood-prone population. The hazard information will be requested from public authorities, e.g. hazards maps that have been created in the frame of the EU Floods Directive. Moreover, hazard information from the project I12 will be tested.

Dedicated Regional Cluster: Central Europe / Germany

Related PhD-projects: Q3 (first cohort, Jonas Laudan), P7 (second cohort, Lisa Berghäuser), associated PhD on loss model transferability (Guilherme S. Mohor) and I12 (third cohort)

Responsibilities: The PhD-project “Quantifying changes in exposure, vulnerabilities and risks of pluvial and fluvial floods” is based at the research team “Geography and Disaster Risk Research” of the University of Potsdam. The aim of this PhD-project is to quantify changes in exposure of urban areas and assets towards different types of flooding based on available land use data, including open building data sets (OSM). For future scenarios, the application of land use models and the transfer of their meso-scale output to the micro-scale (i.e. creation of typical building patterns) is foreseen. For the final risk analysis, exposure data will be combined with hazard scenarios and vulnerability models. Implications of (past and potential future) changes in risk for land management should be discussed with stakeholders.

Requirements: We are seeking applications from highly motivated individuals with an excellent Master’s degree in environmental sciences, hydrology, geomatics, geography, data sciences or related fields with a strong background in GIS, machine learning, statistics and modelling. Programming skills are essential. Fluency in the English language (speaking and writing) as well as the willingness to work in an interdisciplinary team are essential. We expect a strong interest in flood vulnerability, exposure and risk research.

References:

Barredo, J. I. 2009. “Normalised flood losses in Europe: 1970–2006.” Natural Hazards and Earth System Science 9 (1): 97–104. https://doi.org/10.5194/nhess-9-97-2009.

Barredo, J. I. 2010. “No upward trend in normalisedwindstorm losses in Europe: 1970-2008.” Natural Hazards and Earth System Sciences 10 (1): 97–104. https://doi.org/10.5194/nhess-10-97-2010.

Bubeck, P., W. J W Botzen, H. Kreibich, and J. C J H. Aerts. 2012. “Long-term development and effectiveness of private flood mitigation measures: An analysis for the German part of the river Rhine.” Natural Hazards and Earth System Sciences 12 (11): 3507–18. https://doi.org/10.5194/nhess-12-3507-2012.

Cammerer, Holger, Annegret H. Thieken, and Peter H. Verburg. 2013. “Spatio-temporal dynamics in the flood exposure due to land use changes in the Alpine Lech Valley in Tyrol (Austria).” Natural Hazards 68 (3): 1243–70. https://doi.org/10.1007/s11069-012-0280-8.

Kienzler, S., I. Pech, H. Kreibich, M. Müller, and A. H. Thieken. 2015. “After the extreme flood in 2002: Changes in preparedness, response and recovery of flood-affected residents in Germany between 2005 and 2011.” Natural Hazards and Earth System Sciences 15 (3): 505–26. https://doi.org/10.5194/nhess-15-505-2015.

Kreibich, H., S. Vorogushyn, H. Apel, D.T. Chinh, A.K. Gain, N.V. Dung, K. Schröter, et al. 2017. “Adaptation to flood risk: Results of international paired flood event studies.” Earth’s Future 5: 953–65. https://doi.org/10.1002/eft2.232.

Laudan, Jonas, Gert Zöller, and Annegret H. Thieken. 2020. “Flash floods versus river floods-a comparison of psychological impacts and implications for precautionary behaviour.” Natural Hazards and Earth System Sciences 20 (4): 999–1023. https://doi.org/10.5194/nhess-20-999-2020.

Sieg, Tobias, Kristin Vogel, Bruno Merz, and Heidi Kreibich. 2019. “Seamless Estimation of Hydrometeorological Risk Across Spatial Scales.” Earth’s Future 7 (5): 574–81. https://doi.org/10.1029/2018EF001122.

Thieken, Annegret H., Holger Cammerer, Christian Dobler, Johannes Lammel, and Fritz Schöberl. 2016. “Estimating changes in flood risks and benefits of non-structural adaptation strategies - a case study from Tyrol, Austria.” Mitigation and Adaptation Strategies for Global Change 21 (3): 343–76. doi.org/10.1007/s11027-014-9602-3.