ارزیابی جامع برای ظرفیت حمل و نقل منابع آب در شهر شیان چین
Abstract
1- Introduction
2- Study area
3- Data sources and methods
4- Establishing the evaluation index system and SD model for the WRCC in Xi'an
5- Results and discussion
6- Conclusions
References
Abstract
The quantity and quality of water resources are of great importance in maintaining urban socio-economic development. Accordingly, substantial research has been conducted on the concept of the water resources carrying capacity (WRCC). In this study, analytic hierarchy process (AHP) and system dynamics (SD) models were combined to construct a multi-criteria evaluation system of the WRCC and a socio-economic/water resources SD model for Xi'an. The developmental trends of the society, economy, water supply/demand, and wastewater discharge were obtained from 2015 to 2020 using five scenarios designed for distinct purposes; these scenarios and trends were comprehensively evaluated using a combination of qualitative and quantitative analyses. The results indicated that the WRCC (0.32 in 2020) in Xi'an will shift from a normal to a poor state if the current social development pattern is maintained; therefore, we conclude that the socio-economic development of Xi'an is unsustainable. However, under a comprehensive scheme, the WRCC index (0.64 in 2020) will increase by 48% compared with the WRCC index under a business-as-usual scenario. Further, some practical suggestions, including the promotion of industrial reforms and the improvement of water-use efficiency and recycling policies, were provided for improving the regional WRCC.
Introduction
Water resources, which constitute an irreplaceable foundation of social development, are one of the most important natural resources for the survival of organisms (Walter et al., 2012). Coincident with the rapid development of contemporary society, the discrepancies between acute water shortages and increasing demands for water resources have become more prominent (Cai et al., 2011a,b; Safavi et al., 2016). In recent years, human activities have led to an enormous demand for water resources accompanied by water resource shortages and water quality degradation; these demands have led to water crises in many regions, particularly in urban areas (Tan et al., 2013; Wu et al., 2014). Nearly two-thirds of cities in China face different degrees of water shortages, and the groundwater in some areas is overexploited (Shang et al., 2016). Moreover, rapid urbanization has introduced many new pollution-related challenges, such as the need to collect and treat increasing volumes of city sewage (Chen, 2007). Over the last two decades, it has been estimated that more than 11,000 water qualityrelated emergencies have occurred. A recent example is the discovery of severe water contamination in the Jialing River caused by the discharge of wastewater from chemical plants containing high amounts of thallium (Han et al., 2016). Though cities represent a concentration of water resource demands, urban development has caused serious threats that have focused the public's attention on the importance of protecting existing water resources (Bakker, 2010). In 2014, Chinese Premier Li Keqiang publicly declared war on pollution in an economic overhaul, and the Chinese Central Government has since issued a series of policies in the field of pollution control and remediation (Han et al., 2016). Thus, quantitative and qualitative evaluations of whether available water resources can support socio-economic development are important for ensuring that the accessible water environment is not destroyed.