This paper analyzes the changing trends of the Lower Yellow River(LYR) transverse profile parameters and their aberrance points by the time series analysis method.Research results show that there has been a trend of c...This paper analyzes the changing trends of the Lower Yellow River(LYR) transverse profile parameters and their aberrance points by the time series analysis method.Research results show that there has been a trend of changes in the LYR channel transverse profile parameters since the 1950s.The main river channel has a tendency of shrinkage year by year and the trend will be continued in the future.The main features of the LYR channel shrinkage are remarkable reductions of bankfull dis-charges and bankfull areas,corresponding decreases of bankfull widths,average bankfull water depths and maximal bankfull water depths,as well as increases of bankfull water levels and width-depth ratios accompanied.The discriminant parameters for threshold of the LYR main channel shrinkage were put forward.It indicates that the LYR main channel began to shrink in the 1970s and has entered into a serious phase of channel shrinkage since the 1990s.The incompatible index of discharged water-sediment processes of the Sanmenxia Reservoir was introduced,which revealed that there was a trend of increasing in the incompatibility between water flow and sediment load.Response relations between the LYR main channel shrinkage parameters and discharged water-sediment processes of the Sanmenxia Reservoir were founded,which indicate that the LYR main channel shrinkage can be mitigated and improved through the regulation of discharged water-sediment processes of the reservoir,especially through the regulation of water-sediment incompatible index.The LYR channel for water and sediment transportation can be restored and maintained.展开更多
由于受人类活动及气候变化影响,黄河上游干流水沙特征发生显著变化。为探究黄河上游水沙变化情况,基于黄河上游5个水文站19642019年水沙、遥感影像等数据,利用Mann-Kendall检验法、滑动t检验法、累积距平曲线和双累积曲线等突变检验方...由于受人类活动及气候变化影响,黄河上游干流水沙特征发生显著变化。为探究黄河上游水沙变化情况,基于黄河上游5个水文站19642019年水沙、遥感影像等数据,利用Mann-Kendall检验法、滑动t检验法、累积距平曲线和双累积曲线等突变检验方法和小波分析法,对黄河上游水沙变化特征进行研究。利用水沙关系曲线及线性回归法等方法估算人类活动和气候对水沙变化的贡献率,并着重讨论梯级水库建设及土地利用变化对水沙的影响。结果表明:1)黄河上游玛曲-小川段流域内降雨量和径流量变化幅度不明显,贵德站、循化站、小川站19862019年年均输沙量分别减至19641985年的9.8%、24.6%、38.8%,输沙量大大减少。黄河上游玛曲-小川段径流量突变多在1986年,输沙量突变多在1969、1986、2004年,径流量存在8、16、22 a周期,输沙量存在4~8、18~21、27 a周期。2)1969年后,河流输沙能力增强,水沙关系显著改变。在不同时段内,人类活动对径流量变化在19872019年贡献率为66.3%,对输沙量变化在19701986、19872004、20052019年的贡献率为72.96%、70.73%、69.7%。人类活动对黄河上游干流水沙影响占据主导因素。3)刘家峡水库淤积最为严重,单库运行期水库淤积量为2.39亿t,排沙比变化范围为1.39%~10.7%。梯级水库联调使得径流量在19642004年间减少47.8%,19642019年间梯级水库减沙94.8%,梯级水库对输沙量影响远大于对径流量的影响。4)19802020年间,草地面积增加了1880.03 km 2,增幅3.1%,有利于减少输沙量,草地拦沙效益大于截流效益。展开更多
文摘This paper analyzes the changing trends of the Lower Yellow River(LYR) transverse profile parameters and their aberrance points by the time series analysis method.Research results show that there has been a trend of changes in the LYR channel transverse profile parameters since the 1950s.The main river channel has a tendency of shrinkage year by year and the trend will be continued in the future.The main features of the LYR channel shrinkage are remarkable reductions of bankfull dis-charges and bankfull areas,corresponding decreases of bankfull widths,average bankfull water depths and maximal bankfull water depths,as well as increases of bankfull water levels and width-depth ratios accompanied.The discriminant parameters for threshold of the LYR main channel shrinkage were put forward.It indicates that the LYR main channel began to shrink in the 1970s and has entered into a serious phase of channel shrinkage since the 1990s.The incompatible index of discharged water-sediment processes of the Sanmenxia Reservoir was introduced,which revealed that there was a trend of increasing in the incompatibility between water flow and sediment load.Response relations between the LYR main channel shrinkage parameters and discharged water-sediment processes of the Sanmenxia Reservoir were founded,which indicate that the LYR main channel shrinkage can be mitigated and improved through the regulation of discharged water-sediment processes of the reservoir,especially through the regulation of water-sediment incompatible index.The LYR channel for water and sediment transportation can be restored and maintained.
文摘由于受人类活动及气候变化影响,黄河上游干流水沙特征发生显著变化。为探究黄河上游水沙变化情况,基于黄河上游5个水文站19642019年水沙、遥感影像等数据,利用Mann-Kendall检验法、滑动t检验法、累积距平曲线和双累积曲线等突变检验方法和小波分析法,对黄河上游水沙变化特征进行研究。利用水沙关系曲线及线性回归法等方法估算人类活动和气候对水沙变化的贡献率,并着重讨论梯级水库建设及土地利用变化对水沙的影响。结果表明:1)黄河上游玛曲-小川段流域内降雨量和径流量变化幅度不明显,贵德站、循化站、小川站19862019年年均输沙量分别减至19641985年的9.8%、24.6%、38.8%,输沙量大大减少。黄河上游玛曲-小川段径流量突变多在1986年,输沙量突变多在1969、1986、2004年,径流量存在8、16、22 a周期,输沙量存在4~8、18~21、27 a周期。2)1969年后,河流输沙能力增强,水沙关系显著改变。在不同时段内,人类活动对径流量变化在19872019年贡献率为66.3%,对输沙量变化在19701986、19872004、20052019年的贡献率为72.96%、70.73%、69.7%。人类活动对黄河上游干流水沙影响占据主导因素。3)刘家峡水库淤积最为严重,单库运行期水库淤积量为2.39亿t,排沙比变化范围为1.39%~10.7%。梯级水库联调使得径流量在19642004年间减少47.8%,19642019年间梯级水库减沙94.8%,梯级水库对输沙量影响远大于对径流量的影响。4)19802020年间,草地面积增加了1880.03 km 2,增幅3.1%,有利于减少输沙量,草地拦沙效益大于截流效益。
