Deltas host a variety of unique ecosystems at the land-sea interface. They are also among the most densely populated areas in the world and already affected by climate change. In an interdisciplinary approach and together with societal partners, we explore pathways to sustainable deltas in the future.
Water, Climate & Future Deltas
Delta areas, as unique ecosystems, are among the most densely populated areas in the world. Deltas are under increasing human and natural pressure. Future global change, with intensifying human activity, increasing weather extremes, changing river flow regimes and accelerated sea-level rise, will put deltas and their societies at increasing risk.
We therefore need deltas that are resilient to natural hazards, make sustainable use of natural resources, have healthy environmental conditions, and are able to cope with future climate change and sea-level rise. It is now the moment for science and society to find sustainable pathways into such future. This requires addressing the wide variety of processes - physical, chemical, biological, institutional and socio-economic – that interact in deltas in an integrated approach.
In the hub Water, Climate and Future Deltas researchers from varying disciplines at Utrecht University cooperate with external partners to design and evaluate pathways to sustainable delta development. The hub will provide policy makers and delta managers with the essential scientific basis for informed decision-making on pathways towards sustainable deltas.
Finding pathways to sustainable delta development requires understanding both the external drivers of change and the functioning and interaction of natural and social systems that can be managed in a delta. Therefore, the hub comprises three research lines that together are required for sustainable development:
Research line A - Development of integrated scenarios for external conditions for delta pathways
In this research line a two-step approach is used to develop integrated scenarios of changes in deltas that determine the boundary conditions for delta pathways in the future. First the global scale external drivers will be identified. We will look both in to changes that determined overall trends in the past, but as well as future scenarios. The answers are obtained from understanding external boundary conditions, natural variability, the functioning and interactions between natural and social subsystems, and how these shaped the pathway to our present-day deltas. Furthermore, we will identify how and why the current pressures will affect deltas in the coming century.
Some key external boundary conditions that drive the delta pathways in the future are described below, including available tools for analysis:
- Socio-economic drivers as population growth, water and food demand, energy production and technological developments: the Integrated Model to Assess the Global Environment (IMAGE)
- Climate change: Historical data analysis of past and sub-recent climate and climate variability. For the future, we will use scenarios based on the IMAGE implementation of the SSP scenarios. The work will be done in cooperation with PBL Netherlands Environmental Assessment Agency and Koninklijk Nederlands Meteorologisch Instituut (KNMI)
- Socio-economic and land-use changes and their results including the supply of water, sediment and nutrients towards deltas, water use, contaminant production and river engineering: Biophysical impact models, the UU modelling instrument PCR-GLOBWB, and historical data analysis of past and sub-recent climate and climate variability, sediment records from upstream basins, delta lakes, and coastal waters
- Sea-level rise : Sea level scenarios will be developed for Global sea-level models in collaboration with NIOZ Sea Level Centre and KNMI.
In the second step the global scenarios are downscaled to the delta level using the changes in the local physical system (e.g. changes in climate, sea level, upstream river basins) and the socio-economic conditions (e.g. changes in technology, crop use, regional economic prosperity).
Dr. Roderik van de Wal (Utrecht University - Institute for Marine and Atmospheric Research)
Prof. Detlef Van Vuuren (Utrecht University - Geosciences - Copernicus)
Prof. Marc Bierkens (Utrecht University - Geosciences - Physical Geography)
Research line B - Delta system functioning
This research line aims at understanding the natural and social internal drivers, controls and feedback processes and their impacts in deltas and their shallow coastal waters. For several delta areas we will answer the questions ‘What is the current state?’, and ‘How did we get here? ‘. The current state and development history form the starting point for current and future delta functioning and management. This understanding is obtained from in-depth research of subsystems and environmental drivers of specific case areas in deltas.
The subsystems and drivers we will focus on are:
- Bio-morphodynamics of rivers, estuaries, tidal basins, delta lakes, and coastal front
- Ecology of coastal waters
- Wetlands, ecosystems and land subsidence
- Ecosystem functioning and services
- Delta cities: flood protection, subsidence, climate proofing, city Blue Print
- Social-cultural setting and perspectives
- Regional economic development, feedback mechanisms, resilience and perspectives
- Institutional organisation and Legal arrangements
Starting from the knowledge, obtained in the first step of this research line, a framework is established for modelling the biophysical effects and social impacts of combined scenarios and management measures in deltas. Examples are the effects of sea-level rise on groundwater salinity, or the governance requirements for new flood protection measures.
The models will provide the knowledge basis to answer the question ‘How do we get there?’. The models will be used for 1) the evaluation of possible sustainable pathways under a given scenario of external and internal drivers, 2) to further elaborate these pathways by examining the effects and feedbacks, and 3) to assess the implementation of these pathways in terms of governance and law.
- Dr. Esther Stouthamer (chair; Utrecht University-Geosciences- Physical Geography)
- Dr. Mariet Hefting (Utrecht University-Science-Biology)
- Dr. Frank van Laerhoven (Utrecht University-Geosciences -Copernicus)
- Prof. Tjeerd Bouma (Utrecht University-Geosciences, Royal Netherlands Institute for Sea Research - Estuarine & Delta Systems / Coastal Systems)
- Prof. Katja Philippart (Utrecht University-Geosciences, Royal Netherlands Institute for Sea Research - Estuarine & Delta Systems / Coastal Systems)
- Prof. Annelies Zoomers (Utrecht University-Geosciences - Human Geography and Planning)
- Prof. Huib De Swart (Utrecht University-Science-Institute for Marine and Atmospheric Research)
- Dr. Frank Groothuijse (Utrecht University-Law, Economics and Governance)
Research line C- Exploring sustainable pathways
This research line aims to design story lines for future delta development and to identify pathways towards sustainable deltas under various scenarios of external and internal drivers. Specific story line themes that will be addressed include (combinations of): land-use change and urbanization, water use and freshwater scarcity, land subsidence, flooding, salinization, urban climate, biodiversity and ecosystem services.
A first step in this research line is the identification of ‘forces’ that potentially effect pathways in the course of time. These forces include policy objectives, the key-impacts of natural or socio-economic drivers that may affect policy decisions (coastal erosion, flooding, economic crisis), management strategies with possible measures, requirements for legitimate and effective institutional, legal, economic and governance arrangements, evaluation criteria for delta functioning and policy arrangements, and sustainability. For this identification of forces the scenarios, knowledge and models from research line A and B are used.
The hub will develop the actions, knowledge and instruments that are essential to develop management pathways, both for specific local delta environments and entire deltas. Based on theory and local context, the hub will develop evaluation criteria for delta quality, resilience and sustainability. Furthermore different generic types of solutions will be studied and evaluated, including e.g. water technology, building with nature, and its implementation through law and governance arrangements.
The establishment and evaluation of pathways is more of an intuitive, explorative and creative process with strong interactions between the different subsystems, and within-pathway feedback loops between delta state and management. Therefore, activities in this research line comprise creative sessions, including ‘expert-judgements’ as well as serious gaming labs, on the design and evaluation of pathways. Sessions will be organised on-site for stakeholders for site cases (Living labs) as well as for entire deltas.
- Prof. Martin Wassen (chair; Utrecht University - Geosciences - Copernicus)
- Prof. Hans Middelkoop (Utrecht University - Geosciences - Physical Geography)
- Prof. Marleen Van Rijswick (Utrecht University - Law, Economics and Governance)
- Prof. Remco Veltkamp (Utrecht University - Science - Information and Computing Sciences)
- Prof. Wouter Botzen (Utrecht University - Law, Economics and Governance - Utrecht University School of Economics)
The hub will work together closely with stakeholders in a co-creative process across a range of delta environments with long-term challenges, starting with the Rhine-Meuse delta in the Netherlands, the Mekong delta in Vietnam, and the Mississippi delta in the United States.
Activities and deliverables
- Research activities and output
- Set-up of collaborative living labs
- Knowledge sharing and dissemination
- Policy briefs
- Educational activities
We invite partners from all disciplines working on sustainable delta development to join the hub and collaborate with us to find pathways to sustainable deltas.
Current partners of the hub are: