一、序言 灌溉工程的经济效益是指灌溉和未灌溉相比较,所增加的农、林、牧业产品(包括主、副产品,以下简称农业产品)的产量或产值,灌溉前、后的农业产品的产量都可以根据设计灌区附近地区的调查统计资料分析得出。如果设想灌溉前、后的农业技术措施(包括肥料、种籽、植物保护、耕作条件及田间管理等)基本相同,那么灌溉后比灌溉 I. Introduction The economic benefits of irrigation projects refer to the output or output value of the increased agricultural, forestry and animal husbandry products (including primary and side products, hereinafter referred to as agricultural products), the agricultural products before and after irrigation Yield can be based on the statistical analysis of the surveyed areas in the vicinity of the design irrigation areas. If it is assumed that agricultural techniques (including fertilizers, seeds, plant protection, farming conditions and field management, etc.) before and after irrigation are basically the same,