张掖市水价改革的定量研究——基于引入水土账户的CGE模型

The impact of Zhangye's water price reform on the economy and water saving using Water-Land CGE model

近几年黑河流域的水资源供需问题已经得到政府的关注,其中农业用水价格的调整是改革的重点。张掖市是黑河流域水资源的主要消耗区,本文以张掖市为例,采用引入水土账户的CGE模型模拟分析水价改革的经济影响和节水效益。结果表明:(1)水价改革对经济仅有微弱影响,仅带来0.091%的GDP损失;(2)但在节约用水方面的效益却很大,将节约9.568%的水资源使用、万元GDP耗水量下降9.384%;(3)节约的水资源类型主要是地下水,且全部来自用水强度高的农业;(4)水土资源在需求总量上减少了,并表现出从农业部门向非农业部门转移的趋势;(5)在行业产出上,仅玉米、果蔬等几个对水资源依赖程度高的农业部门受到打击,产出平均下降4.1%。综上,通过价格杠杆可以实现较好的节水效益,但要关注改革过程中对特色优势农业的冲击以及不同类型水资源之间的消费替代转移。

Increasing the water resource use price of agriculture sectors has been an important policy instrument in improving the sustainable use of water resources of the Heihe River basin.Zhangye city is the main consumer of Heihe River basin＇s water resources. Taking Zhangye as an example,we explored the impact of agricultural water price reform on Zhangye＇s economy and water- savings using a water- land integrated computable general equilibrium model（CGE）. The model adopted a highly disaggregated agricultural sector profile and highlights three types of water resources in the production structure. These two features allowed us to better characterize the output change in different agricultural crops in the face of a water price shock,and to explore in detail how an agriculture planting structure adjustment and different types of water resource price adjustment can be conducted to generate minor negative economic impacts but obvious watersavings. Simulation results show that the reform only has minor negative impacts on the economy,with 0.091% loss for Zhangye＇s GDP;the benefit from water- saving is obvious with a 9.568%decrease for total water use and 9.384% decrease for water consumption per million GDP.Agriculture sectors were found to be the only contributor to water-savings,with underground water being the main conservation water resource type. Water and land resources are expected to move from agriculture sectors to non-agriculture sectors. Only agriculture sectors experienced a negative shock,with outputs decreasing 4.1% on average. The negative performance of agriculture sectors is due to high water consumption coefficient and increasing water use cost. Our analysis enriches our understanding of the impact of price leverages on water conservation and emphasizes that government should pay attention to the initial negative impact on agriculture and price substitution effect among different water resources.