Evolution characteristics and influencing factors of the measured runoff in the main stream of the Yellow River
[Objective]This study aims to comprehensively elucidate the mechanism of runoff evolution in the Yellow River Basin,and to provide a scientific basis for further exploration of water resource management and sustainable development in the basin.[Methods]From the perspective of functional data,the properties of trend,mutation,periodicity and seasonal variation of the measured runoff volume on the main stream of the Yellow River from 2002 to 2022 were investigated by techniques including phase plane analysis,principal differential analysis and basis function fitting.Additionally,the differences in runoff volumes among major hydrological stations were analyzed by functional clustering.Furthermore,cumulative slope change analysis was employed to quantify the contribution rates of climate change and human activities on runoff changes,and a multivariate functional linear regression model was established to estimate the relationship between climate change/human activities and runoff.[Results]The measured runoff volume displayed an increasing trend with significant periodicity,experiencing abrupt changes in 2004,2008,2013,2017 and 2021 with distinct seasonal characteristics.Based on the spatial distribution patterns of annual runoff,the twelve main hydrological stations along the Yellow River could be classified into three categories.Climate factors(precipitation,temperature and water consumption)and human activities had been proved to notably influence the measured runoff.[Conclusion]Over the past 20 years,the measured runoff from the main stream of the Yellow River had exhibited an increasing trend with distinct spatial distribution characteristics among hydrological stations,indicating that the measured runoff volume was significantly impacted by climate change and human activities.
functional data analysisYellow River Basinmeasured runoff