论文部分内容阅读
总结近年来在汉江上游古洪水研究成果的基础之上,采用文献资料分析和洪水模拟计算方法,对汉江上游6个沉积剖面纪录的东汉时期古洪水事件进行了年代考证和洪水模拟计算。结果表明,通过分析文献记载的汉江上游东汉时期洪水影响范围、强度和程度,以及结合洪痕沉积规律,在时间上考证认为这6个沉积剖面记录的东汉时期古洪水事件可能是东汉建安二年(197年)九月的一次特大洪水事件。选取合适的河槽横断面和糙率系数,采用HEC-RAS模型对距离较近的4个沉积面记录的东汉时期古洪水事件进行洪水模拟计算,模拟洪水位与各剖面依据古洪水SWD恢复的洪水位误差在-0.18%~0.25%,而且模拟的1983年洪水位与剖面及其附近发现的1983年洪痕水位误差小于0.25%,说明洪水模拟计算选取的河槽横断面和水文参数准确、可靠,从洪水模拟计算的角度也说明了汉江上游沉积记录的东汉时期古洪水事件可能为一次特大洪水事件。该研究结果不仅延长了汉江上游洪水序列,而且也为汉江上游水利工程建设、水资源管理和防洪减灾等提供重要的水文资料。
Based on the research results of the ancient floods in the upper reaches of the Hanjiang River in recent years, the paper uses the literature data analysis and flood simulation methods to study the paleo-flood events in the Eastern Han Dynasty recorded by six sedimentary sections in the upper Hanjiang River. The results show that the ancient flood events in the Eastern Han Dynasty recorded by the six sedimentary sections may be the two years of Jian’an in the Eastern Han Dynasty by analyzing the range, intensity and extent of floods recorded in the Han Dynasty in the upper reaches of the Han River as well as the sedimentation rules of flood marks. (197 years) in September a major flood event. The HEC-RAS model was used to simulate the flood events of ancient flood events recorded during the Eastern Han Dynasty from the four sedimentary surfaces close to each other, and the simulated flood level and floods recovered from each section based on SWD Bit error is between -0.18% and 0.25%, and the simulated 1983 flood level and its vicinity are less than 0.25% of the flood level in 1983, indicating that the cross section and hydrologic parameters of the fluvial channel selected by the flood simulation are accurate and reliable, From the point of view of flood simulation calculation, it is also shown that the flood events in the Eastern Han Dynasty recorded by sedimentary records in the upper reaches of the Hanjiang River may be an extraordinary flood event. The results of this study not only prolong the flood sequences in the upper reaches of the Han River, but also provide important hydrological data for water conservancy project construction, water resources management and flood control and disaster mitigation in the upper reaches of the Han River.