Research on the evolution law of hydrological situation in the water source area of the Hanjiang-to-Weihe River Valley Water Diversion Project under future climate scenarios

Abstract

[Objective] To explore the water resource situation in the water source area of the Hanjiang-to-Weihe River Valley Water Diversion Project under climate change conditions, and to ensure the efficient and sustainable operation of major cross basin water transfer projects.[Methods] Three scenarios(SSP1-2.6, SSP3-7.0, SSP5-8.5) under the CMCC-ESM2 climate model in the 6th International Coupled Model Intercomparison Program(CMIP6) were used to drive the SWAT model of the water source area of the Hanjiang-to-Weihe River Valley Water Diversion Project, and to analyze the evolution trend of hydrological conditions in the water source area of the Hanjiang-to-Weihe River Valley Water Diversion Project under future climate scenarios.[Results] The result showed that from 2025 to 2100, under the SSP1-2.6 scenario, the precipitation and runoff in the water source area showed a decreasing trend, while the highest and lowest temperatures showed an increasing trend. However, the precipitation and runoff in the near future(2025—2050), medium term(2051—2075), and long term(2076—2100) were higher than those in the reference period(1980—2020); Under the SSP3-7.0 scenario, precipitation, runoff, and highest and lowest air temperatures all show an increasing trend. However, under the SSP3-7.0 scenario, the precipitation in the near, medium, and long term is lower than the baseline period, and the recent runoff is also lower than the baseline period; Under the SSP5-8.5 scenario, precipitation, runoff, and maximum and minimum temperatures also show an increasing trend, with recent, medium-term, and long-term precipitation and runoff all higher than the baseline period.[Conclusion] In the future, with the increase of radiation forcing, there will be a trend of warming and wetting in the water source area of Hanjiang-to-Weihe River Valley Water Diversion Project. By simulating future climate change and analyzing the evolution trend of hydrological conditions in the water source area of the Hanjiang-to-Weihe River Valley Water Diversion Project, scientific basis and theoretical support can be provided for the allocation and management of water resources in the project and the utilization of regional water resources.

Keywords

climate change / Hanjiang-to-Weihe River Valley Water Diversion Project / SWAT / CMIP6 / runoff simulation / precipitation / global warming / hydrological situation