北京市水资源政策对水资源承载力的影响研究

The Effects of Water Resources Policies on Water Resources Carrying Capacity in Beijing City

在对北京市水资源承载力特征及其影响政策分析的基础上,提出用系统动力学(SD)来定量研究不同政策对水资源承载力的影响。在水资源合理配置的前提下,以北京市社会经济环境系统为研究对象,建立北京市水资源系统动力学模型,并将水资源承载力指标融合在模型中进行计算。通过动态仿真模拟,预测北京市5项水资源政策———实施应急供水工程、推进再生水回用、调整工业产业结构、发展农业节水灌溉和提高用水价格对水资源承载力的长期影响,为确保北京市用水的长期安全和社会经济的持续发展提供科学的决策依据。研究表明,应急供水工程政策对北京市水资源承载力的影响最大,而若同时实施这5项政策,到2010年,可承载的工业总产值、农业总产值和非农业人口将分别达到9663×108元、417×108元和1527×104人。

Water is one of the most essential natural resources, especially for urban cities. Water shortage is a common problem confronted by many cities, including Beijing. A number of policies have been presented to solve the challenge. Accurate evaluation on the effects of water resources polices can be an efficient tool for water resources management. In the areas suffering from water shortage, water resources carrying capacity （WRCC） can be taken as a principle indicator of water resources security. And the effect of water resources polices on WRCC in Beijing City is evaluated in this paper. Based on the research of characteristics and influencing polices about WRCC, the industrial production value, the agricultural production value and the urban population were chosen as indexes of WRCC. Since WRCC of Beijing City has been influenced by an intricate system consisted with population, economics and governance subsystems, a new method is necessary to cover the complexities. And System Dynamics （SD）,founded by J.W. Forrester in the 1950s, has been testified to be an effective way to the analysis of strategies and decision-making. So it is applied to quantitatively reflect the effects of water resources policies on WRCC in this paper. In order to achieve both conservation and effective utilization of water resources, a SD model for water resources of Beijing City is developed. It consists of modules about water resources exploitations, population,industry, agriculture and environment,which are integrated with a group of dynamic equation, while WRCC indexes are also incorporated in the model. The software VENSIM is applied for quantitatively analysis of the model. After inputting original data and various velocities of variables, the effects of five polices on WRCC of Beijing City are simulated, including the urgent supply of water resources projects, the utilization of the gray water, the adjustment of industrial structure, the water conservation agriculture and the huff of water prices. According to the results of dynamical simulation, the effects and influences of the long-run impact of each policy on WRCC are fully clarified. The final result indicates that： 1 ） the urgent supply of water resources projects has the most significant effect on WRCC, which can improve the industrial production value of WRCC to a higher level of 675.9 billion Yuan in 2010; 2）if the five policies are all put in practice since 2003, the industrial production value of WRCC, the agricultural production value of WRCC and the urban population of WRCC of Beijing City in 2010 will reach 996.3 billion Yuan,41.7 billion Yuan and 15.27 million respectively. The results in this paper can be a scientific foundation for water resources usage and conservation in Beijing.