Energy consumption due to groundwater pumping for irrigation in the North China Plain

Irrigated agriculture consumes a large amount of groundwater resources with a huge energy requirement, and this has seriously restricted the development of green and efficient agriculture in China. However, recent studies on energy consumption for irrigation focus mainly on individual irrigation systems or single wells, and few spatial-temporal energy assessments have been carried out at regional scale. This is needed for effective management of regional energy consumption for groundwater utilization. Based on single-well pumping method, a distributed energy consumption model for groundwater irrigation (DPE_GI) was proposed in this study. The North China Plain (NCP) was selected as the research area, which is a typical groundwater irrigated area and has severe issues with aquifer depletion. The results showed that the average annual energy consumption for groundwater pumping was 13.67 billion kW h, and the energy consumption per area was 1122.4 kW h hm^-2 under the winter wheat - summer maize rotation system in NCP. Current groundwater pumping energy consumption in the NCP is 2.9 times of the initial value in 1986, and the NCP has already become the world's largest energy consumer for groundwater irrigation. Due to the uncertainty of precipitation, energy consumption for irrigation fluctuates per growing season. Groundwater level also impacts energy consumption. Popularizing water-saving irrigation technology such as drip or sprinkler irrigation, changing cropping systems and habits can effectively reduce energy consumption for irrigation.