中国节水灌溉工程对经济和环境的影响

ECONOMIC AND ENVIRONMENTAL IMPACTS OF WATER-SAVING IRRIGATION PROJECTS IN CHINA

关键词:  节水灌溉  投资效果  成本收益分析  农业产业  CGE模型

Key words:  water-saving irrigation  effect of investment  cost-benefit analysis  agricultural industry  CGE model

摘要:

目的 为缓解水资源短缺对农业的不利影响，我国制定“十四五”全国农业绿色发展规划，2021—2025年计划新增400万hm²高效节水灌溉工程。文章旨在评估节水灌溉工程的经济和环境效益，以支持更有效的投资决策。方法 依据节水灌溉工程成本收益数据，分析了管灌、喷灌、微灌的微观经济效益。考虑到这些投资的外部性，进一步使用中国动态CGE模型评估了投资对农业用水消耗和GDP的综合影响。该模型可以综合评估政策对经济和环境的影响，较好量化投资综合收益。结果 节水灌溉工程直接收益微薄甚至亏损，但通过产业链的相互关联，投资的间接经济收益高于直接收益。节水灌溉工程节水量为0.22~0.32 m3/元，节水的环境收益为0.86~1.26元/元，经济收益与环境收益相加后的投资回报率为0.60~5.55元/元。不同作物的投资回报率存在差异，蔬菜微灌投资收益显著高于粮食节水灌溉工程投资。不同工程的投资回报率亦有差别，对粮食而言，喷灌工程综合投资回报率最高。结论 节水灌溉工程投资的经济和环境综合收益巨大，且不同作物、不同设施之间存在差异，应优化节水灌溉工程投资结构，鼓励投资侧重于粮食喷灌工程与蔬菜微灌工程。

Abstract:

To mitigate the negative impact of water scarcity on the economy, it is necessary to increase the efficiency of water resource utilization. China has formulated the "14th Five-Year Plan" for the construction of a water-saving society, and plans to add 4 million hm² of high-efficiency water-saving irrigation projects from 2021 to 2025. It is necessary to analyze the economic and environmental benefits of water-saving irrigation project investment, to support more effective investment decision-making. Based on the cost-benefit data of water-saving irrigation projects, this paper evaluates the economic benefits of pipe irrigation, sprinkler irrigation and micro-irrigation for grain and vegetables. Considering the externalities of these investments, the study further employs the China Dynamic CGE model to assess the comprehensive impact of investments on agricultural water consumption and GDP. This model can comprehensively evaluate the impact of policies on economy and environment, and can quantify the comprehensive benefit of investment. The results show that the direct benefit of water-saving irrigation project is low or even loss, but through the correlation of industrial chain, the indirect economic benefit of investment is higher than the direct benefits. Simultaneously, investment in water-saving irrigation projects can produce significant water-saving benefits. For each yuan invested, the water saving amount is 0.14m3~0.37m3, the environmental benefit of water saving is 0.86 yuan ~ 1.26 yuan, and the return on investment (ROI) after adding economic and environmental benefits is 0.60 yuan ~5.55 yuan. The ROI of different crops is different. with water-saving irrigation projects for vegetables showing significantly higher returns compared to water-saving irrigation projects for grain. The ROI of different facilities is also different. For grain, the comprehensive ROI of sprinkler irrigation is the highest. In conclusion, the comprehensive economic and environmental benefits of water-saving irrigation projects investment are huge, and there are differences between different crops and different facilities, so the investment structure of water-saving irrigation projects should be optimized, and investment focusing on grain sprinkler irrigation projects and vegetable micro-irrigation projects should be encouraged.