Cost-effectiveness analysis of water-saving irrigation technologies based on climate change response: A case study of China

This study provides a cost-effectiveness analysis of four water-saving irrigation techniques that are widely implemented in China to address the impacts of climate change: sprinkler irrigation, micro-irrigation, low-pressure pipe irrigation and channel lining. The aim is to thoroughly understand the economic feasibility of water-saving irrigation as an approach to coping with climate change. Based on the cost-effectiveness analysis, this study finds that water-saving irrigation is cost-effective in coping with climate change, and has benefits for climate change mitigation and adaptation, and for sustainable economic development. For the cost-effectiveness ratio of mitigation and adaptation, only that of channel lining is negative (for mitigation is -43.02 to -73.41US$/t, for grain yield increase -34.35 to -20.13US$/t, and for water saving -0.020 to -0.012US$/m³). Sprinkler irrigation has the highest incremental cost for mitigation (476.03-691.64US$/t), because when sprinkler irrigation is used, there may be additional energy needs to meet water pressure requirements, which may increase greenhouse gas emissions compared to traditional irrigation. For mitigation, in districts where the pumping head for pressure is lower than the critical energy saving head, sprinkler irrigation should be avoided. Micro-irrigation has the highest incremental cost for adaptation followed by sprinkler irrigation and low-pressure pipe irrigation, but when considering the revenues from improved adaptation, all of the measures assessed are economically feasible. The results suggest that for mitigation and adaptation objectives, micro-irrigation performs best. From an economic perspective, channel lining is recommended. Therefore, a balanced development of channel lining and micro-irrigation according to different geographical conditions is recommended.