黑河中游正义峡径流变化趋势及归因分析 postprint

Abstract: This study utilized measured runoff data from the Zhengyi Gorge hydrological station in the middlereaches of the Heihe River to analyze the trend and mutation years of the runoff sequence from 1970 to 2020.Various methods, including linear regression, the Mann- Kendall mutation test, the sliding T mutation test, thePettitt test, and cumulative offset verification, were employed for the analysis. Additionally, an attributionanalysis of the runoff changes at the Zhengyi Gorge hydrological station was conducted using the Budyko waterenergycoupled balance equation. The results indicate the following: (1) Over the study period, the runoff atZhengyi Gorge showed fluctuations, alternating between periods of abundance and contraction but showed anoverall increasing trend. The runoff experienced a mutation in 2004, resulting in a 3.08 × 108 m³ increase inaverage annual runoff volume, representing a growth rate of 32.7%. (2) In the period after the mutation (2005-2020), the elastic coefficients of runoff in response to precipitation, potential evaporation, and underlying surfaceparameters were 1.40, -0.40, and -1.57, respectively. The contribution rates of each factor to runoff were 42.73%,−12.52%, and 69.79%, respectively, indicating that runoff is most sensitive to underlying surface changes andthat precipitation has a more significant impact on runoff than potential evaporation among climate factors. (3)Under certain regional climatic conditions, the changes in the underlying surface of the middle reaches caused byhuman activities, such as vegetation cover, land use, and watershed water transfer, are the main reasons for thechanges in runoff at Zhengyi Gorge. The research findings can provide a scientific basis for river basinmanagement departments to formulate water resource allocation and utilization plans.