滴水尽其用

Make Wise Use of Every Drop

将水资源短缺归因于水资源在时间和空间上的不均匀分布,以及供给和需求的不平衡。对于前者,采用跨流域调水和蓄水来解决;对于后者,采用增加供给与控制需求的方法。首先使用灰色模型预测2025年全国各省市水资源需求与供给的缺口;然后建立4个模型,分别从调水、蓄水、海水淡化、节水4个方面讨论了改善水资源的状况。使用运输模型求得跨流域调水的最优解,使用库存论中的报童模型求取满足下游需求的最优蓄水量,使用净现值分析方法比较得出海水淡化点的布局,使用拉姆齐定价确定水价策略以达到节水目的;最后,根据模型给政府提供了决策参考,并且对4个代表性的区域提出详细方案。

We attributed water scarcity to uneven distribution in space and time and imbalance between supply and demand.We solved the former by transferring water across regions and storing water for future use,and for the latter we considered supplyaugmentation and demand constraint methods.We first used a grey model to predict gap between demand and supply in 2015.Results are that there will be 15 provinces in short of water.Jiangsu province,the most severe case,will be faced with 58.32 billion of water shortage.Next we developed four models to address water transfer,water storage,desalinization and water conservation.A transportation model was applied to determine an optimal transfer strategy.Results suggested that we transport12.32 billion of water from the Songliao Region to the Haihe Region,and 5.2billion of water from the Long River to the Yellow River.We applied a news-vendor model to determine optimal amount of water needed.A case study of Three Gorges Reservoir revealed that 84.1billion of water should be stored now to satisfy water demand in 2025.A NPV analysis of desalinization projects indicated that 4desalinization plants should be built in Shanghai,and several more in other provinces in need of water.A Ramsey pricing model was used to determine an optimal pricing strategy.A case study of Shaanxi province revealed that increasing block tariffs achieves a demand reduction of 17.8per person per year.Finally,we provided a guide for government to make decisions and propose specific measures for four representative regions.Our models are conceptual ones and solutions are based on mathematical optimization.So with more precise data we are able to modify our results without much burdensome repetitions.