机构地区:[1]黄河水利科学研究院水利部黄河下游河道与河口治理重点实验室,郑州450003 [2]河海大学水文水资源与水利工程科学国家重点实验室,南京210098 [3]郑州黄河河务局惠金黄河河务局,郑州450045
出 处:《长江科学院院报》2024年第5期8-17,25,共11页Journal of Changjiang River Scientific Research Institute
基 金:黄河水利科学研究院发展基金项目(黄科发-202006);黄河水科学研究联合基金项目(U2243220);水利部泥沙科学与北方河流治理重点实验室开放基金项目(IWHR-SEDI-2022-07)。
摘 要:黄河下游游荡性河段素以调整速度快与幅度大著称,河道心滩复杂多变,探究心滩形态特征与水沙过程之间的响应关系对于解析下游游荡性河段的河床演变机制具有重要的意义。围绕黄河下游铁谢至高村游荡性河段的心滩面积与数量等形态特征指标,结合下游水沙及冲淤特性,采用遥感影像和数值模拟相结合的研究方法厘清游荡性河段水沙过程与心滩面积及数量之间的响应关系,揭示水沙变化对心滩形态特征的影响机制。结果表明:自小浪底水库运用以来,下游河道发生剧烈冲刷,游荡性河段累计冲刷量15.37亿m^(3),占下游累计冲刷量的68%;在小浪底水库运用以前,游荡性河段的心滩面积与数量年际变化剧烈,存在着明显的增长与降低变化过程,而小浪底水库运用以后,该河段的心滩面积与数量呈现先减小后增大再减小的变化趋势;随着4 a滑动汛期平均流量和4 a滑动汛期平均来沙系数的增加,游荡性河段的心滩面积及数量分别呈现出减小和增大的变化趋势。数值模拟方法不仅可以较好地再现心滩发育及演变过程,还可以定性地表征特定水动力学因素对心滩形态特征塑造的影响,为阐明游荡性河段的心滩演变理论提供了一种新的研究方法。研究成果不仅有助于阐明河流平面形态的调整过程,还可为今后河道整治工程的布局提供理论支撑。The wandering reach of the lower Yellow River are characterized by rapid adjustments and significant morphological changes,particularly evident in the complexity and variability of mid-channel bars.Understanding the response relationship between morphological characteristics of these mid-channel bars and the water-sediment processes is crucial for analyzing the evolution mechanisms in the wandering reach of the lower Yellow River.In this study we examined the morphological features(area and quantity)of mid-channel bars along the wandering reach from Tiexie to Gaocun.Based on water-sediment and scouring-deposition characteristics,we elucidated the relationship between the area and quantity of mid-channel bars and the water-sediment processes to unveil the mechanisms underlying the impact of hydrological changes on mid-channel bar morphology via remote sensing and numerical simulation.Our findings reveal that since the operation of Xiaolangdi Reservoir,the downstream channel has experienced significant erosion,with the wandering reach contributing 68%of the cumulative scouring in the downstream,reaching 1.537 billion m^(3).Before the operation of Xiaolangdi Reservoir,mid-channel bars in the wandering reach exhibited notable interannual fluctuations in area and quantity,characterized by periods of growth and decline.However,after the operation,the area and quantity of mid-channel bars initially decreased,followed by an increase,and then subsequent decline.Moreover,along with the increase of four-year sliding average flow rate and incoming-sediment coefficient during flood seasons,the area and quantity of mid-channel bars displayed downward and upward trends,respectively.Numerical simulations not only accurately replicate the development and evolution of mid-channel bars but also elucidate the qualitative impact of specific hydrodynamic factors on their morphology.This comprehensive analysis not only advances our understanding of river plane morphology adjustments but also provides theoretical insights for future riv
关 键 词:心滩演变 水动力学模型 水沙过程 游荡性河段 形态特征
分 类 号:TV143[水利工程—水力学及河流动力学]
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