北京市城市绿化用水的供需风险评估

北京市水资源短缺的问题已成为制约社会经济发展和影响社会稳定的重要因素之一,因此,如何协调北京市城市绿化与水资源的合理有效利用问题亟需得到解决。基于北京市城市绿化现状及水资源利用现状,采用尺度扩展法,计算了2012年北京市城市绿化的生态需水量,并结合北京市有效降雨利用量和实地调查数据,求得2012年北京市城市绿化的理论供水量和实际供水量。在此基础上,利用灰色马尔科夫链模型与熵值法对北京市城市绿化供水的3种来源(地表水、地下水、再生水)做出评估,得出2014年实际供水量预测值区间。2012年北京市理论供水量为5.07×10⁸ m³,实际供水量为6.86×10⁸ m³。2014年预测实际供水量区间为7.29×10⁸~7.93×10⁸ m³。评估结果表明,北京市仍存在城市绿化用水供需风险问题,并据此提出相关节水措施和建议,为保障北京城市供水安全与水资源可持续利用相关研究提供参考和借鉴。

Risk Assessment of Water Supply and Demand for Urban Greening in Beijing City

Water resources shortage has become one of the important factors restricting the economic development and the social stability of Beijing City, so it is a fatal time to coordinate urban greening and water resource. Based on the current situation of urban greening and water utilization in Beijing City, the authors calculated the ecological water demand of urban greening by scale extending computing methods, and by effective utilization of rainfall combined with survey data to calculate the theoretical and actual water supply of Beijng's urban greening in 2012. On this basis, the three sources of Beijing's water supply for urban greening, which including surface water, ground water and reclaimed water, were evaluated by the gray Markov chain model and entropy evaluation method, thus obtained the predicted value of water actual supply in 2014. The results indicated that the theoretical water supply was 5.07×10⁸ m³ and the actual amount of water was 6.86×10⁸ m³ in 2012, possible range for the actual amount of water is between 7.29×10⁸ m³ and 7.93×10⁸ m³ in 2014. Accordingly, there have risks of Beijing's greening water supply and demand, so the authors provides some advice about water-saving measures and related research references to ensure Beijing's urban water supply security and sustainable utilization of water resource.