Ward et al. (2020) The need to integrate flood and drought disaster risk reduction strategies

Identification

• Journal: Water Security
• Year: 2020
• Date: 2020-11-10
• Authors: Philip J. Ward, Marleen de Ruiter, Johanna Mård, Kai Schröter, Anne F. Van Loon, Ted Veldkamp, Nina von Uexkull, Niko Wanders, Amir AghaKouchak, Karsten Arnbjerg‐Nielsen, Lucinda Capewell, María Carmen Llasat, Rosie Day, Benjamin Dewals, Giuliano Di Baldassarre, Laurie S. Huning, Heidi Kreibich, Maurizio Mazzoleni, Elisa Savelli, Claudia Teutschbein, Harmen van den Berg, Anne van der Heijden, Jelle M.R. Vincken, M. J. Waterloo, Marthe Wens
• DOI: 10.1016/j.wasec.2020.100070

Research Groups

• Institute for Environmental Studies, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
• Centre of Natural Hazards and Disaster Science (CNDS), Uppsala, Sweden
• Department of Earth Sciences, Air, Water and Landscape Science, Uppsala University, Uppsala, Sweden
• German Research Centre for Geosciences, Section Hydrology, Potsdam, Germany
• Amsterdam University of Applied Sciences, Amsterdam, the Netherlands
• Department of Peace and Conflict Research, Uppsala University, Sweden
• Department of Physical Geography, Utrecht University, Utrecht, the Netherlands
• Department of Civil and Environmental Engineering, University of California, Irvine, CA, USA
• Department of Earth System Science, University of California, Irvine, CA, USA
• Department of Environmental Engineering, Technical University of Denmark, Lyngby, Denmark
• School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
• Department of Applied Physics, University of Barcelona, Spain
• Hydraulics in Environmental and Civil Engineering (HECE), University of Liège, Liège, Belgium
• Department of Civil Engineering and Construction Engineering Management, California State University, Long Beach, CA, USA
• Acacia Water, Gouda, the Netherlands

Short Summary

This paper synthesizes existing literature to demonstrate how disaster risk reduction (DRR) measures for floods or droughts can have unintended positive or negative impacts on the risk of the opposite hazard, and how these measures can be negatively impacted by the opposite hazard. It highlights the critical need for a more holistic, integrated approach to flood and drought risk management.

Objective

• To examine examples of (a) how flood or drought DRR measures can have unintended positive or negative impacts on the risk of the opposite hazard, and (b) how flood or drought DRR measures can be negatively impacted by the opposite hazard.

Study Configuration

• Spatial Scale: Global, with examples from various regions including California (USA), Australia, the Netherlands, Afghanistan, Amazon basin, Brazil, Perth (Australia), South Asia, Thailand, Mediterranean region, Mexico, Mozambique, Ghana, Niger, Fiji, Argentina, and Catalonia (Spain).
• Temporal Scale: Historical (e.g., 1995–2015, past century, specific events like Millennium Drought 1997–2009, 2012–2017 California drought, 2018 Kerala floods), current, and future projections under climate change.

Methodology and Data

• Models used: Not applicable; this is a literature review and synthesis paper. It discusses findings from studies that may have used various models (e.g., hydrological, economic impact simulations).
• Data sources: Existing scientific literature, case studies, and reports on floods, droughts, and disaster risk reduction measures.

Main Results

• Most research and DRR strategies focus on either flood or drought risk, despite both being extremes of the same hydrological cycle.
• Flood or drought DRR measures can have unintended consequences:
  • Dikes and levees (flood DRR): Can reduce groundwater recharge, increase water demand in protected areas (levee effect), and require water for wetting during dry periods, thus increasing drought risk. Droughts can also cause dike failures.
  • Dams (multi-purpose DRR): Flood protection favors low reservoir levels (reducing drought preparedness), while drought protection favors high levels (increasing flood risk). Dams can also increase evaporation and create a false sense of security, leading to increased exposure downstream. Floods contribute to reservoir sedimentation, reducing storage capacity.
  • Stormwater Control Measures (SCM) and upstream measures (flood DRR): Can store water for evaporative cooling and as a source during drought, and increase groundwater recharge. However, droughts can adversely affect green infrastructure (e.g., green roofs).
  • Subsurface storage (drought DRR): Managed aquifer recharge (MAR) can increase water availability during drought and reduce peak flows. However, continued groundwater pumping can lead to land subsidence, increasing flood risk. Flooding can damage MAR infrastructure and contaminate stored water.
  • Migration (exposure/vulnerability DRR): Relocating people from flood-prone to drought-prone areas can increase drought vulnerability. Unplanned urbanization due to migration can increase flood risk and strain water resources. Droughts can also hinder migration by reducing people's means to move.
  • Agricultural practices and land use changes (exposure/vulnerability DRR): Water and soil conservation methods (e.g., successive dams, water harvesting) can reduce both drought and flood risk. However, enhanced infiltration can lead to waterlogging, and extensification of agriculture can reduce ecosystem services like flood prevention. Reforestation can reduce dry season flows in some contexts. Wrong forecasts can lead to major losses and mistrust.
  • Socioeconomic vulnerability and preparedness (vulnerability DRR): Measures increasing overall socioeconomic development generally reduce vulnerability to both hazards. However, a focus on one hazard can decrease preparedness for the other, and false alarms from early warning systems can lead to maladaptation (e.g., releasing water for a predicted flood that doesn't materialize, causing water shortage).
• Key challenges for a holistic approach include: scale differences, complexity of interactions, understanding physical climate processes (e.g., compound events), human decision-making and risk perception, effectiveness of measures, and governance structures (e.g., separate government departments for flood and drought management).

Contributions

This article provides a comprehensive synthesis of the complex, often unintended, interactions between flood and drought disaster risk reduction measures. It moves beyond single-hazard approaches by illustrating with concrete examples how actions taken for one hydrological extreme can impact the risk of the other, highlighting the need for integrated, multi-hazard risk management. It identifies critical knowledge gaps and challenges for achieving a more holistic approach, linking DRR with climate change adaptation and Sustainable Development Goals.

Funding

• Dutch Research Council (NWO) VIDI grant [grant number 016.161.324] (P.J. Ward, M.C. de Ruiter)
• Swedish Research Council [grant number 2016-06389] (N. von Uexkull)
• Spanish National Project M-CostAdapt [CTM2017-83655-C2-2-R] (M. Carmen Llasat)
• Interreg V A project PIRAGUA [210/16] (M. Carmen Llasat)
• Dutch Research Council (NWO) VENI grant [016.Veni.181.049] (N. Wanders)
• EU H2020 project RECONECT [grant no. 776866] (K. Arnbjerg-Nielsen)

Citation

@article{Ward2020need,
  author = {Ward, Philip J. and Ruiter, Marleen de and Mård, Johanna and Schröter, Kai and Loon, Anne F. Van and Veldkamp, Ted and Uexkull, Nina von and Wanders, Niko and AghaKouchak, Amir and Arnbjerg‐Nielsen, Karsten and Capewell, Lucinda and Llasat, María Carmen and Day, Rosie and Dewals, Benjamin and Baldassarre, Giuliano Di and Huning, Laurie S. and Kreibich, Heidi and Mazzoleni, Maurizio and Savelli, Elisa and Teutschbein, Claudia and Berg, Harmen van den and Heijden, Anne van der and Vincken, Jelle M.R. and Waterloo, M. J. and Wens, Marthe},
  title = {The need to integrate flood and drought disaster risk reduction strategies},
  journal = {Water Security},
  year = {2020},
  doi = {10.1016/j.wasec.2020.100070},
  url = {https://doi.org/10.1016/j.wasec.2020.100070}
}