Specific Types and Adaptability Evaluation of Managed Aquifer Recharge for Irrigation in the North China Plain

The North China Plain is the main grain production district in China, with a large area of well irrigation resulting in a large groundwater depression cone. In the 1970s and 1980s, small-scale managed aquifer recharge (MAR) projects were developed to recharge shallow groundwater, which played an important role in ensuring stable and high crop yields. MAR projects are divided into 10 types based on local water conservancy characteristics. The combined use of well canal irrigation has been widespread in the Yellow River Irrigation District of Shandong Province for nearly 40 years, where canals play multiple roles of transporting and storing Yellow River water or local surface water, recharging groundwater and providing canal irrigation. Moreover, the newly developed open channel underground perforated pipe shaft water saving irrigation system can further expand the scope and amount of groundwater recharge and prevent system clogging through three measures. Finally, an adaptability zoning evaluation system of water spreading has been established in Liaocheng City of Shandong Province based on the following five factors: groundwater depth, thickness of fine sand, specific yield, irrigation return flow, and groundwater extraction intensity. The results show that MAR is more adaptable to the western region than to the eastern and central regions.