摘要
古洪水水文学研究是全球变化研究领域的前沿科学。通过对近年来古洪水成果的整理发现,汉江上游郧县段4个沉积剖面--晏家棚(YJP)、尚家河(SJH)、归仙河口(GXHK)和弥陀寺(MTS)均记录有北宋时期(960~1 127 CE)的古洪水事件。通过对4个沉积剖面所在河段的研究,根据实测的河槽断面数据、水文参数以及设计推求的古洪水流量过程,采用HEC-RAS模型模拟了北宋古洪水的演进过程及古洪水水面线。此外,采用2010年"7·18"洪水进行了模型的可靠性验证。结果表明:与调查的古洪水水位相比,4个沉积剖面处的模拟水位误差介于-0.31%~0.34%之间,说明这4个沉积剖面极有可能记录一次古洪水事件;洪峰在研究河段内演进历时约1.15 h且削减不足1%,这符合研究河段的洪水传播特性。该研究对于认识汉江上游特大洪水的演进规律具有重要的科学意义,为流域的洪水设计、洪水预测及防洪减灾提供一定的基础数据与科学支撑。
Paleoflood research is a frontier science in the field of global change research.Currently,paleoflood hydrology research focuses on the reconstruction of water level and discharge based on a single sediment profile.However,few simulation studies of paleoflood events were conducted based on multiple sedimentary profiles of long-reach areas.In this study,a paleoflood event that took place during the Northern Song Dynasty was studied based on four sedimentary profiles of the Yunxian reach of Hanjiang River,Hubei Province,China,i.e.,Yanjiapeng(YJP),Shangjiahe(SJH),Guixianhekou(GXHK),and Mituosi(MTS)profiles.In addition,a paleoflood hydrology investigation on the river sections,where the four sedimentary profiles are located,was conducted based on the measured terrain data and hydrological parameters.The water surface profile and peak discharge(Q=57500 m3•s-1)of the paleoflood event that occurred during the Northern Song Dynasty were reconstructed.The simulated water-level errors within the four sedimentary profiles were between-0.31%and 0.34%,which confirms the water surface simulated with the HEC-RAS model.Furthermore,a paleoflood flow process was designed based on the typical flood process measured in the hydrological station.Subsequently,the paleoflood routing in the Northern Song Dynasty was simulated based on the unsteady flow modeling using the HEC-RAS model.The results indicated that the paleoflood peak from the YJP to the MTS profiles lasted about 1.15 h,and the loss in the flood-peak discharge was less than 1%.The water depth measured upstream was found to be greater than that measured downstream,whereas the flow velocity showed opposite results.Based on the inundation area,it can be concluded that the high-risk areas for flooding in the study reach are mainly located near the banks of the Hanjiang River,which is mainly affected by the bedrock canyon.This study has a considerable scientific significance because it help understand the catastrophic flood movements within the upper reaches of the Hanjiang River,as it provides essential data for flood design,forecasting,and prevention as well as disaster mitigation within the basin.
作者
王光朋
查小春
黄春长
庞奖励
张国芳
WANG Guang-peng;ZHA Xiao-chun;HUANG Chun-chang;PANG Jiang-li;ZHANG Guo-fang(School of Geography and Tourism,Shaanxi Normal University,Xi,an 710119,Shaanxi,China)
出处
《干旱区地理》
CSCD
北大核心
2020年第4期967-976,共10页
Arid Land Geography
基金
自然科学基金重点项目(41030637)
国家社会科学基金项目(14BZS070)
国家自然科学基金重点项目(41271108)资助。
关键词
古洪水研究
北宋时期
HEC-RAS模型
防洪减灾
汉江上游
palaeoflood research
Northern Song Dynasty
HEC-RAS model
flood prevention and mitigation
upper reaches of Hanjiang River
