摘要
阶梯式水价在节约用水,提高水资源利用和分配效率上具有重要的意义,在很多城市的自来水供应中都计划采用阶梯式水价,现有的水价模型基本上都没有考虑阶梯式水价,因此推行阶梯式水价在理论上也就有一定的盲目性。根据经济学的观点,将自来水按照用水量的多少分为不同的阶梯,在名义上视为不同的商品,在效用函数的基础上,根据线形支出系统理论,建立模拟阶梯式水价和用水量之间关系的模型,为实施阶梯式水价提供理论依据。并以北京市为例,利用本文所建立的阶梯式水价模型,模拟了阶梯式水价的实施所产生的节水效果。假设实行3个阶梯上的水价,年消费量在30m3以下水价为2.5元/m3,年消费量在30m3到50m3水价为5元/m3,年消费量在50m3以上水价为25元/m3,如果该水价执行后2000年的人均年用水量可以从46m3减少到36.4m3,人均用水减少量22%,同时还保证了居民的基本生活用水。
Increasing water demand is inconsistent with dwindling water supply in many cities of China and other countries. There are 400 cities that run short of water and 110 cities that are seriously lack of water. Therefore, it is essential to protect water environment by preventing water from pollution and saving water from lavish water demand.
Water price plays an important role in urban water demand. There are two kinds of water price, unitary water price and scalar water price. Unitary water price is deficient in restraining lavish water demand. On the contrary, scalar water price can ensure fundamental water demand and restrain lavish water demand. At present there is no water pricing model that can simulate water demand and scalar water price yet.
Unitary price of urban water cannot promote efficient water allocation. In some cities scalar water price will be put into practice, but the outcome of such policy is unpredictable for lack of theoretical support. In this study, urban water was classified by the volume of water usage based on the linear expenditure system （LES）, which is widely used to represent household demand systems in lots of countries, and scalar water was considered as different kinds of goods. Cheap water is still water, but expensive water is considered as other goods, analogous to oil when water is very expensive. A pricing model was made to simulate the relationship between scalar water price and water usage, which can support decision makers.
This model was then used to simulate the effect of scalar water price in Beijing, which is the capital of China and is a water shortage area. Three kinds of water price are supposed for in the year 2000, which are 2.5 yuan/m^3 when water demand is less than 30 m^3, 5 yuan/m^3 when water demand is between 30 m^3 and 50 m^3, and 25 yuan/m^3 when water demand is higher than 50 m^3. If this water pricing policy is put into practice, one person will consume 36.4 m^3 in one year from 46 m^3 , which is actually consumed in the year 2000. Therefore in Beijing this policy can save 22% lavished water, at the same time the fundamental water demand can still be fulfilled.
出处
《资源科学》
CSSCI
CSCD
北大核心
2006年第1期109-112,共4页
Resources Science
基金
国家自然科学基金重点项目:流域生态需水规律及时空配置研究(编号:50239020)
关键词
自来水
水价模型
效用函数
阶梯式
Urban water
Water pricing model
Utility function
Scalar water pricing.
