基于能值理论方法的农田灌溉气候调节效益估算

Estimation of climate regulation benefits of farmland irrigation based on energy theory

传统的农田灌溉效益估算只考虑经济效益,不利于处理好农田灌溉与生态环境、经济发展的相互关系,构建现代化农田灌溉体系应充分考虑农田灌溉生态效益。采用水量平衡相关理论和能值理论方法构建农田灌溉气候调节效益模型,并以陕西省为例核算出2008-2018年不同区域的气候调节效益值,对影响因素进行了分析。结果表明:关中地区气候调节效益最大,陕北地区气候调节效益最小,陕南、关中和陕北气候调节单方水效益分别约为0.0110、0.0350、0.0069元/m3;经济发展水平程度是影响气候调节效益高低的关键要素;三大典型区域的农田气候调节单方水效益随时间变化总体呈上升趋势。

The conventional estimation of farmland irrigation benefits has only taken economic benefits into consideration,which is unfavourable for dealing well with the correlation of farmland irrigation,ecological environment and economic development. To establish modernized farmland irrigation system,its ecological benefits should be substantially considered. We established a benefit model of climate regulation for farmland irrigation using relevant theories of water balance and energy theory,and then took Shaanxi Province as an example to calculate the climate regulation benefits in different regions from 2008 to 2018 and analyzed the influencing factors. The result show that the climate regulation benefits were greatest in Guanzhong region,but lowest in northern Shaanxi,and the climate regulation benefits per square meter in southern Shaanxi,Guanzhong and northern Shaanxi were 0. 011 0 yuan/m^3,0. 035 0 yuan/m^3 and0. 006 9 yuan/m^3,respectively. It is found that the extent of economic development is the key factor influencing the climate regulation benefits,and the farmland climate regulation benefits per square meter in the three typical regions rise with time in general.