Application of Entropy Method to Quantify Future Ecological Flow in the Yellow River Basin

Area of Science:

• Hydrology
• Climate Science
• Environmental Science

Background:

• Yellow River basin faces decreased precipitation and runoff due to anthropogenic and climate change impacts.
• Sustaining human and ecosystem needs is increasingly pressured by water scarcity.

Purpose of the Study:

• To evaluate future flow conditions in the Yellow River basin and assess their adequacy for ecological flow requirements.
• To analyze the impact of climate change on the Yellow River's ecological flow using hydrological modeling.

Main Methods:

• Applied an entropy-based method to calculate flow duration curves (FDCs) from observed and simulated data.
• Utilized H08 and DBH hydrological models for climate change impact assessment.
• Analyzed decadal FDCs under RCP 2.6 and RCP 8.5 climate change scenarios.

Main Results:

• Simulated FDCs showed good agreement with observed data and each other.
• Future decadal FDCs are predicted to be higher, indicating increased water availability under both RCP scenarios.
• High flows are projected to increase faster than low flows, with Q95 and Q90 values generally exceeding ecological thresholds at most stations.

Conclusions:

• Most Yellow River stations are projected to meet future ecological flow requirements, with minimal threat at Lanzhou, Wubao, Longmen, and Huayuankou.
• Toudaoguai, Sanmanxia, and Tangnaihai stations may still face challenges in satisfying ecological flow demands, indicating localized water stress.