| 05 May 2026
Supporting climate change adaptation worldwide: A web application for exploring uncertain future changes in water resources
Abstract. While adaptation to changing water resources due to climate change is necessary everywhere, information about their potential future changes has not been easily accessible to most climate change adaptation processes. The free interactive web application Climate Change Impact of Water Resources (CCIWR) Explorer presents the output of a multi-model ensemble of global hydrological models. It provides state-of-the-art information to support participatory climate change adaptation processes worldwide. What makes the CCIWR Explorer unique is its ability to inform climate change adaptation decisions that account for stakeholder risk aversion. It not only shows the projected median future change in total water resources, groundwater resources, and evapotranspiration in the four seasons or annually, but also which fraction of the ensemble members project a change that stakeholders consider hazardous. Three visualizations are provided: Two map views as well as “Local Insights”, percentile boxes showing the range of future changes in individual 0.5° grid cells. The Explorer was evaluated regarding effectiveness, efficiency, operability, user engagement, and beneficialness. This was achieved through an online user survey, in which 21 pilot users familiarized themselves with the web application by completing two tasks before evaluating various aspects of the Explorer. On average, user satisfaction was high. Satisfaction and the number of correct answers are positively correlated with user expertise. Based on experiences with using multi-model ensemble projections to inform stakeholders in three participatory processes, we recommend that experts, such as water engineers and climate managers, consult the CCIWR Explorer to inform stakeholders. The Explorer is also suited to direct use by university students and researchers.
This well-written paper provides an introduction to and evaluation of a web-based tool, designed by the authors, to support climate change adaptation: the Climate Change Impact of Water Resources (CCIWR) Explorer. While very thorough and informative in introducing the tool and in sharing the results of the evaluation, the scope of the paper is perhaps somewhat limited. Specifically, the paper currently does not put forth a larger argument/main point as part of an effort to address gaps in existing knowledge in geoscience communication. Prompting questions for the authors are whether and how they can apply the evaluation toward a more generalizable purpose (e.g., lessons learned that apply broadly to the advancement of geoscience communication and beyond the improvement specifically of this tool). There is one comment made at the end of the paper to this effect (pg. 21, starting line 495), but it does not quite offer readers a great deal of insight into the reasons why the evaluation of web-based tools is important.
Discussion section 5.1 (starting pg. 14): Here the paper seems to lose its central thread. Rather than discuss the results of the evaluation within existing, relevant literature, there is additional data introduced (i.e., results of discussions in different participatory processes for water management). It seems that for this data to be included in the paper, the approaches/methods used to engage groups and frame discussions should be included within the methods section, and the results of those discussions should be included in the results section. The purpose of the discussion section would then be to discuss the combined results in relation to the existing literature that gives framing to the entirety of the paper (again, the larger argument/main point/gaps in knowledge addressed).
Pg. 15, line 229: The transition between paragraphs is unclear. From here it also becomes a bit difficult to understand the discussion section as it goes into detail about the participatory workshops for which thorough description of methods, etc., is not previously provided (see prior comment). Some of the approach/methods is embedded within this text but not all of it is explained (e.g., line 322 makes reference to previous interviews with stakeholder representatives but it is unclear when, with whom, and for what purpose, etc.).
Similarly, Section 5.2 does not currently contain discussion of results but rather introduces new information (i.e., comparison of CCIWR Explorer with other tools). This comparison is a somewhat difficult to follow in the absence of visual aids.
In sum, it is clear that the authors have put forth significant effort to develop and refine the CCIWR Explorer through different forms of evaluation. To streamline this paper in a way that clearly lays out the different phases of evaluation (in methods and results) and then discusses the combined results in relation to an overarching point the authors choose to make will strengthen it greatly.