汉江上游安康段不同重现期下洪水灾害风险评价

Risk assessment of flood disasters in different return periods along the Ankang reach of the Hanjiang River

依据汉江上游安康段古洪水研究成果,获得实测洪水、历史洪水和古洪水序列下4种重现期的洪峰数据,应用GIS技术、HEC-RAS水文模型,从洪水灾害的危险性和易损性对安康段不同重现期情景下洪水灾害进行风险评估.结果表明,高风险区分布在研究河段干流上游南岸的安康盆地,支流黄洋河两岸为较高风险区,研究河段干流中下游两岸为较低和低风险区;随着重现期增加,高风险区范围不断扩大,低风险区范围逐渐缩小;整体呈研究河段上游南部遇水成灾,北部和中下游地区相对安全的空间分布格局.

Based on research into paleoflood to obtain the flood peak data of different return periods in view of measured flood,historical flood data and paleoflood series,by geo-information system technology and hydrologic engineering center-river analysis system model,the risk of flood disasters in different return periods along the Ankang reach of the Hanjiang River was assessed from the two flowing perspectives:flood disaster and vulnerability.The study results showed that the highest-risk areas for flood disaster were located in the Ankang basin of the study reach;both sides of the Huangyang River were higerrisk areas;the middle and lower reaches of the study reach were lower-risk areas.At the same time,with the return period from 10 to 1000 a,the proportion of high-risk areas was expanding and the proportion of low-risk areas was gradually shrinking.In general,the south areas of the upper reaches of study reach were vulnerable to flood while the middle and lower reaches relatively safe.