Sub-theme leader

YOKOZAWA Masayuki (Waseda University)


Water resources, infrastructure, and food (agriculture) are the most basic and important resources for survival and livelihood. However, the use of these resources is interdependent, with trade-offs and conflicts between stakeholders who use these resources. This situation is under increasing pressure from climate change. Much research has been conducted on the effects of climate change and socio-economic change on each of these resource uses, and adaptation plans for them are being developed. However, studies addressing the assessment of climate change impacts, and the development of adaptation plans that take into account the nexus of water resources, infrastructure, and agriculture have only just begun to be undertaken.

In this context, the objectives of this study are as follows. First, to develop an integrated assessment model for the nexus of climate change impacts and adaptation planning for water, infrastructure, and agriculture at a river basin scale, based on the findings of other themes, sub-themes, and existing studies under this strategic research program. The model will consist of a sub-model describing the temporal and spatial dynamics of each resource in a changing climate environment, and a sub-model describing the interests and decisions of stakeholders who use each resource.

This model will then be used to conduct an integrated analysis and evaluation of the consistency and effectiveness of the adaptation plan for individual adaptation measures with the results of the climate change impact assessment on each resource, taking into account the interactions among stakeholders using the resource. For example, trade-offs and conflicts will be analyzed and assessed to determine whether adaptation plans for the agricultural sector and urban livelihood infrastructure in the same watershed are compatible with common water resources. In addition, if trade-offs and conflicts exist, developing a framework for proposing the direction of their resolution and, ultimately, measures to achieve synergies is also our research aim.

Framework for evaluating climate change adaptation plans in terms of synergies and trade-offs


  • At a river basin scale, develop an integrated assessment model for the water-infrastructure-agriculture nexus based on the knowledge of climate change impact assessments and adaptation plans for water, infrastructure, and agriculture from other themes and sub-themes to be implemented under this strategic research program as well as from the results of existing research
  • The integrated assessment model will be used to analyze and evaluate the consistency and effectiveness of adaptation measures by estimating the situations (trade-offs and conflicts) that would occur in the water-infrastructure-agriculture nexus under a climate change environment at a river basin scale.

Target items

An integrated assessment model for the water resources-infrastructure-agriculture nexus will be developed for the objective watershed. This model will consist of two sub-models.

The first sub-model will be an impact prediction model that estimates the impact of climate change on each resource and the impact of the adaptation plan on the nexus, based on the geographic distribution of water resources, infrastructure development, and agricultural land in the watershed. It will estimate the distribution of water resources in the watershed and simulate crop productivity according to water resource use.

The other sub-model will be an artificial social model that estimates stakeholder decisions and behaviors, and incorporates agent-based model (ABM) techniques. The stakeholders who use each resource as agents are modeled as benefit-based actions and decision-making processes in a climate change environment to simulate stakeholder decision-making and behavior through the interaction of agent groups.

The integrated evaluation model, which combines the these two models, will be used to reflect the dynamically changing stakeholder behavior in the water resources-infrastructure-agriculture nexus in a sequential manner, while providing an integrated analysis and evaluation of the resulting trade-offs and conflicts, and hence, the various adaptation plans for synergy.

As an example, we will analyze whether the adaptation plans of the agricultural sector and urban living infrastructure in the same river basin are compatible via a common water resource, and evaluate the existence of trade-offs and conflicts.

Adaptation options

  • Water management changes to maintain agricultural productivity
  • Spatial and temporal changes in water use in a river basin to maintain available water resources
  • Development of infrastructure for synergy with disaster prevention
  • Propose nudges to support stakeholders’ decision-making