Abstract Wastewater reuse in agriculture can be a viable option to solve future freshwater shortages but may need an additional treatment process (Stage-II) to become a safe option. As wastewater reuse interacts with many facets of coupled human and water systems, the introduction of Stage-II treatment systems in wastewater reuse in agriculture must be understood in terms of socio-hydrology. This paper builds on a place-based socio-hydrological model of a wastewater-reused watershed in South Korea and uses it to: (1) identify key parameters in human and water systems that have a significant impact on wastewater reuse in agriculture; (2) explore the impacts of changing agricultural environments by altering the key parameters; and (3) develop the possibility space of future changes from current decision-making. Key parameters concern the characteristics of urbanization, domestic water use, and greenhouse cultivation. Urbanization can reduce the demand for Stage-II irrigation within an urbanizing watershed by reducing irrigation areas and increasing water availability. Domestic water use has a large impact on the economics of indirect wastewater reuse. Greenhouse cultivation influences the demand for Stage-II irrigation, mainly by reducing water availability. Moreover, it could further affect the demand if the communities evolved to have a greater concern for the use of groundwater resources. The possibility space shows that wastewater reuse has a strong influence on groundwater and could relieve agricultural water deficits through the diversification of irrigation sources, and could be a more economical irrigation practice than groundwater irrigation under changing agricultural environments.

中文翻译：

---

从社会水文模型中获得的见解，以设计流域规模农业的可持续废水再利用策略

摘要 农业中的废水回用可能是解决未来淡水短缺的可行选择，但可能需要额外的处理过程（第二阶段）才能成为安全的选择。由于废水回用与耦合的人类和水系统的许多方面相互作用，因此必须从社会水文学的角度来理解在农业废水回用中引入 Stage-II 处理系统。本文以韩国废水回用流域的基于地点的社会水文模型为基础，并将其用于：(1) 确定人类和水系统中对农业废水回用有重大影响的关键参数；(2) 通过改变关键参数来探索改变农业环境的影响；（3）从当前的决策中发展未来变化的可能性空间。关键参数涉及城市化、生活用水和温室栽培的特征。城市化可以通过减少灌溉面积和增加可用水量来减少城市化流域内对第二阶段灌溉的需求。生活用水对间接废水回用的经济性有很大影响。温室栽培主要通过减少可用水量来影响第二阶段灌溉的需求。此外，如果社区演变为更加关注地下水资源的使用，它可能会进一步影响需求。可能性空间表明废水回用对地下水有很强的影响，可以通过灌溉源的多样化来缓解农业缺水，