Urban water-energy nexus is regarded to be highly important for the sustainable development of cities and the effective management of resources. Research methods on urban water-energy nexus are emerging, and a summary of these methods can help to determine the appropriate tool to manage urban water and energy. The accounting of energy and water in existing nexus research is not consistent, so the results and evaluation are also different. From supply to end-use, account the water and energy consumed in each stage, and the factors that affect the consumption of both in each process are analyzed. Review the latest development of research methods and models in urban water-energy nexus, and propose their advantages and limitations. For systematic models, the determination of parameters and the upgradation are still a huge challenge. In the future, more attention should be paid to the coupling and combination of various methods to understand urban water-energy nexus from a multi-scale perspective. In addition, future research directions should also pay more attention to the internal mechanisms and driving factors of urban water- energy nexus, and how to deal with the nexus under climate change, the interaction with other resources such as food, and the change of urban water and energy under policy control.
Keywords urban water and energy, nexus, accounting, methods and models