Practice and experience of water resources dispatching in the Pi-Shi-Hang Irrigation District

As a mega-scale irrigation district in China, the Pi-Shi-Hang Irrigation District spans the Huai River and Yangtze River basins, covering Anhui and Henan provinces with an effective irrigated area of 0.706 7 million hectares. Characterized by high precipitation variability, diverse water sources, and a complex water supply system, its water resources allocation plays a vital role in ensuring food security, urban-rural water supply, and ecological safety in the Jianghuai region. The district primarily relies on six major reservoirs in the Dabie Mountains as its main water source, supported by a "long vine with melons" water supply system that integrates storage, diversion, pumping, and transfer to meet water demands. During drought years, the Dabie Mountains reservoir group achieves a water utilization rate exceeding 70%, effectively addressing uneven water availability and enabling efficient water resource management. This paper systematically reviews the water resources allocation practices in the Pi-Shi-Hang Irrigation District from 2011 to 2024, analyzing precipitation patterns, drought-flood cycles, and irrigation benefits. Based on practical experience, key strategies are su mmarized including: scientific operation of Dabie Mountain reservoir groups, coordinated multi-source water allocation ("storage-diversion-pumping-transfer"), dynamic crop structure adjustment according to water availability, full utilization of digital twin dispatch systems, and strengthened water resources management and conservation measures. These practices provide valuable references for water resources management in the PiShi-Hang and other irrigation districts.