Analysis of autumn flood characteristics and reservoir scheduling in the upper reaches of the Hanjiang River in 2025

In 2025, a rare "drought and flood emergency" event occurred in the upper reaches of the Hanjiang River. Against the backdrop of 50%～60% drought in the upper reaches of the Hanjiang River from January to mid August, there were 10 consecutive heavy rainfall events from August 25th to October 20th, resulting in 7 numbered floods（No.1 to No.7） in the Hanjiang River Basin. Among them, the No.2 to No.5 floods occurred in a concentrated manner within 15 days, setting a record for the most intensive autumn flood in recorded history. The significant characteristics of this autumn flood were large total rainfall, long duration, extremely dense floods, and huge flood volume. By analyzing its rain and flood characteristics systematically and adopting a scheduling strategy of "advance pre release and release of reservoirs, cascade coordination and peak shaving, dynamic control", the goal is to achieve "zero casualties" in autumn flood defense and double victory in the task of storing 5.884 billion m³ of water for large and medium-sized reservoirs at the end of the flood season to ensure supply.