Methodologies for the study of change in hydrology and society

This paper reports on the progress being made on the “Methodologies” chapter of the Panta Rhei synthesis book due in May 2023 and to be officially launched at 2023 IUGG General Assembly in Berlin. Panta Rhei cornerstone emphasis is to support policies and decision making through better understanding of phenomena that emerge from social and hydrological processes of human water relations and anticipate their future evolution. Different disciplines have different societal objectives or similar objectives with different lens within the domain of Panta Rhei. As a result different are methods used, with their respective challenges. Taking stock of extensive research conducted in the past decade in context Panta Rhei, this chapter identifies a spectrum of methods that have been used to understand and interpret human water relations, with qualitative methods at one end and quantitative methods at the other end of the spectrum. The chapter then synthesizes the methods by proposing that a phenomenon has more than one color in the qualitative-quantitative spectrum when viewed through the prism of interpretation. Taking a couple of examples of phenomena, such as Jevon's paradox, the chapter demonstrates how various methodological colors in the spectrum (qualitative methods such as focus group discussions, surveys and quantitative methods such as agent based models) are needed to interpret its emergence, e.g. as a result of a lack of disincentives in case of Jevons paradox. It is concluded that for the first time diverse disciplines are converging in their pursuit of understanding and predicting human water systems for social good and Panta Rhei has accelerated this convergence. This chapter ends with a call to action on what further methodological developments appear promising and what methods should be more widely adopted, i.e. a celebration of what has been accomplished so far.