描述网络结构的网络效率与弹性力之间的平衡是维持生态系统可持续发展的主要因素。根据生态系统可持续性度量的研究方法，本报告将将生态网络分析中的网络结构分析应用于用水系统的研究中，探讨了网络结构指标网络效率与弹性之间的平衡在用水系统可持续发展中的涵义，提出了适用于用水系统可持续性度量的研究方法，选取了水资源短缺的海河流域、北京和白洋淀流域为案例，从系统整体角度出发研究了这些地区的水资源可持续利用水平以及水生态的承载力。为水资源的规划与管理提供了一种新的研究思路与方法。

Network efficiency and resilience are two equally essential but complementary network structure attributes and a crucial balance between these two factors is critical for ecosystem’s long term sustainability. According to the quantitative measure of sustainability that has been proposed in ecological network theory, the current research introduces and develops this method and its related concepts into water use systems to provide a new angle for studies of sustainable water use. Regarding the difference between ecosystems and water use systems, the meanings of network efficiency and resilience for sustainable development of water use systems are investigated and explained, from which the sustainability of water use systems is defined as the optimal balance of network efficiency and resilience. With three detailed cases studies including Haihe River Basin, Beijing and Baiyang Lake Basin, sustainability of whole water use systems, sustainability of environmental flow and water ecological carrying capacity are researched. Below are the major conclusions and suggestions: 1. To study the sustainability of the water use systems, the method of ecosystems sustainability quantification in ENA is employed as a potential method. A presumed network approach is articulated and then applied in the quantification of water use sustainability in view of network structure. By examining the balance between network efficiency and resilience and its implications for the development of water use networks, the sustainability of such systems from the perspective of an optimal balanced network structure is quantified.2. While water uses of environment and socioeconomic development are linked to water use sustainability closely, they are by no means analyzed separately in terms of sustainable water use. In this study, sustainability of the water use system is highlighted from both socioeconomic and environmental perspectives. Based on network structure analysis, the competing relationship between environmental flow and socioeconomic water uses is explored, from which the sustainable network structure for environmental flow is defined.3. For sustainable water use, water ecological carrying capacity (WECC) is an important issue. Based on researches of network structure analysis in sustainability quantification, with the application of presumed water use network model and a new index, WECC is measured with a value of overload amount from integrated perspective. 4. The results of the application of the network structure analysis in water use systems suggest that it is a promising approach for study of water use systems towards sustainable development. It is expected that with further studies in the future, this method would be developed and be improved as a hopeful tool for water resources regulation and management.