Comparative analysis of greywater recycling and rainwater harvesting as supplementary water sources for conventional urban and tourist resort water supplies

Abstract

Freshwater scarcity combined with high water demand from rapid urbanization, population growth, and changing consumption has resulted in increasing stress on urban water supply systems. Seasonal fluctuations in the population of tourist destinations are especially evident in tourist resorts. Greywater recycling and rainwater harvesting have been proposed as the most widely used valuable strategies to address water scarcity. By taking the conventional water supply system and the water supply of tourist resorts as examples, this study systematically compares and analyzes the advantages and limitations of greywater recycling and rainwater harvesting by enumerating the stress of water supply in different systems, discussing the benefits of both strategies and comparing the differences when using them for tourist destinations. The results showed that pumping systems or elevated tanks used to meet the water supply needs of high-rise buildings pose energy challenges. The water use characteristics of tourist resorts cause it to be closely related to the seasonal influx of tourists. Greywater recycling is more effective than rainwater harvesting in mitigating tourist resorts' water shortage problem. Suggestions for ways to implement these strategies for different regions are also given to make informed decisions about water distribution efforts. This study provides a reference for sustainable urban water resource management.