In view of the need to adapt to uncertain climate change through spatial interventions, this article explores how spatial planners might navigate amid uncertainty. To draw out insights for planning, we examine planning frameworks which explicitly recognise uncertainty and uncertainty descriptions from studies in environmental risk and climate uncertainty. We build our case by addressing the implications of different characteristics of uncertainty and describe how planners can handle uncertainty based on the nature, level and location of uncertainty. We argue that a plural–unequivocal characterisation of uncertainty helps planners in their search for adequate and warranted interventions amid uncertainty.

Adaptive strategies to deal with uncertainty in water management are often collaboratively developed. So far, however, little attention has been paid to the influence of collaboration on handling uncertainty through adaptive planning. In this paper, we study how collaboration has influenced the handling of uncertainty through adaptive planning for water management strategies for the IJsselmeer area in the Netherlands. We show how a fixation on certainty, different perspectives among actors and unclear responsibilities between arenas affect the handling of uncertainty, and found that it is adversely affected by collaboration. The use of adaptive planning challenged current water uses and system functions, creating resistance from actors. We conclude that developing a shared problem perception, creating a common understanding of uncertainties and ensuring a clear demarcation between the water system, its societal functions and water usage, are necessary to make adaptive planning successful in handling uncertainty.

Despite rising attention to pathways thinking in multiple domains such as climate adaptation, energy supply planning, and flood risk management, their spatial translation is so far understudied. We set out to study how spatial design based on pathways thinking can help develop more adaptive and sustainable landscapes. Using landscape analysis, field research, and research-through-designing in a case study on climate resilience in Boston (USA), we argue for better understanding of the spatial and design consequences of pathways in general. Our results indicate that pathways can be spatially translated, demanding landscape-informed choices when sequencing different policy actions. We found that spatial designing makes the landscape consequences of pathways transparent and enables policy-makers to replace the input of policy actions with spatial interventions, select pathways according to different underlying design strategies, use the mapped pathways to initiate an iterative research-through-designing process to test and inform different designs, and spatially visualize the pathways and possible sequences of actions. We conclude that policy-makers should be cognizant about the spatial implications of pathways and offer directions to enrich applications of pathways thinking for achieving adaptive and sustainable landscapes.

Planners and water managers seek to be adaptive to handle uncertainty through the use of planning approaches. In this paper, we study what type of adaptiveness is proposed and how this may be operationalized in planning approaches to adequately handle different uncertainties. We took a comparative case study approach to study two planning approaches: the water diplomacy framework (WDF) and adaptive delta management (ADM). We found that the approaches differ in their conceptualization of uncertainty and show that different types of adaptiveness are used in the approaches. While WDF builds on collaborative adaptive management as a set of ongoing adjustments and continuous learning to handle uncertainty, ADM deliberately attempts to anticipate future adaptations through a set of tools which allows for seizing opportunities and avoiding lock-in and lock-out mechanisms. We conclude that neither of the approaches is fully able to account for different uncertainties. Both approaches may benefit from specific insights in what uncertainty and adaptiveness entail for the development of water management plans.

In many delta areas hydraulic structures are key elements in water management strategies for fresh water supply and flood risk management. Adaptation of delta areas to changing climatological and societal conditions will be in pace with the renovation and replacement of these hydraulic structures. Since hydraulic structures are prone to deterioration, their performance diminishes over time. Changes in society, the economy, and the physical environment can also alter the functionality of structures, or have an impact on their performance. Although faced with deterioration and exogenous changes, timing of replacement is essential because replacing too early leads to insufficient use of invested capital, while replacing too late leads to loss of societal benefits. This article explores the timing of replacement using adaptation tipping points. We indicate three drivers – deterioration, biophysical change, and socio-economic change – that determine the moment in time when replacement becomes necessary. Moreover, we conclude that for determining the moment of replacement, at the very least, the objectives, maintenance and operations of hydraulic structures need to be taken into account. This exploration is illustrated with the task of replacing seven hydraulic structures in the River Meuse.