滇中引水工程水源区与受水区径流丰枯遭遇及水文干旱研究

Study on Encounter of Runoff Abundance and Scarcity Between Source Area and Receiving Area of the Central Yunnan Irrigation Project and the Hydrological Drought

滇中引水工程水源区为金沙江虎跳峡河段,受水区为云南滇中高原区,研究两者径流丰枯遭遇及水文干旱变化趋势,可为滇中引水工程的水资源调度和区域水旱灾害防御提供理论指导。通过多元Copula函数描述径流系列的独立结构,运用游程理论基于标准化径流指数分析水源区和受水区的水文干旱历时、烈度和重现期,用于定量评估滇中引水工程水源区和受水区径流丰枯遭遇情况及其对水文干旱的影响。结果表明,滇中引水工程供水后,水源区标准化径流指数变幅较小,其识别的水文干旱事件历时、烈度和重现期也相对平稳;受水区标准化径流指数变幅较大,其识别的水文干旱事件历时变短、烈度减弱、重现期增大,特别是严重干旱、多年干旱事件。这说明实施滇中引水工程可有效增加受水区水资源量,显著提高受水区水旱灾害防御能力。

The water source area of the Central Yunnan Irrigation Project is the Hutiaoxia section of the Jinshajiang River,and the receiving area is the Central Yunnan Plateau.Studying the flow richness and drought encounter and logical hydro-drought trends between the two can provide theoretical guidance for the water resources dispatch of the Central Yunnan Irrigation Project and the regional water and drought disaster defense.By describing the independence structure of the runoff series with multivariate Copula functions,the theory of run-length is used to analyze the hydrological drought duration,intensity,and recurrence based on the standardized runoff index in the water source area and the ing receiv-area.The flow richness and drought encounter and its impact on hydrological drought in the water source area and the receiving area of the Central Yunnan Irrigation Project is evaluated quantitatively.The results show that the standardized runoff index in the water source area changed little after the project,and the hydrological drought events recognized were relatively stable in duration,intensity,and recurrence;The standardized runoff index in the receiving area changed ly,great-and the recognized hydrological drought events were shorter in duration,weaker in intensity,and longer in rence,recur-especially severe droughts and multi-year droughts.This shows that the implementation of the Central Yunnan rigation Ir-Project can effectively increase the water resources in the receiving area and significantly improve the water and drought disaster defense in the receiving area.