一种基于县城中心的汇流时间计算方法  

A method of calculating travel time based on county center

作　　者：胡畔 陈波[1,2,3] 史培军[1,2,3] 陈学泓 HU Pan;CHEN Bo;SHI Peijun;CHEN Xuehong(Key Laboratory of Environmental Change and Natural Disaster of Ministry of Education,100875,Beijing,China;Academy of Disaster Reduction and Emergency Management,Ministry of Civil Affairs & Ministry of Education,100875,Beijing,China;Faculty of Geographical Science,Beijing Normal University,100875,Beijing,China)

机构地区：[1]北京师范大学环境演变与自然灾害教育部重点实验室,北京100875 [2]北京师范大学民政部/教育部减灾与应急管理研究院,北京100875 [3]北京师范大学地理科学学部,北京100875

出　　处：《北京师范大学学报（自然科学版）》2018年第6期781-789,共9页Journal of Beijing Normal University(Natural Science)

基　　金：国家自然科学基金资助项目(41501020;41621061)

摘　　要：预测洪水传播时间是洪水预警工作的一项重要内容.本文以湘江流域地区的51个县城建成区的中心点为子汇水区出口,划分各个县城的集水面积,并计算瞬时单位线,分析坡面流速、河道流速、河网提取阈值等因素对瞬时单位线的影响.结果表明:河道流速比坡面流速对涨洪历时的长短影响更显著;坡面流速比河道流速对于洪水总历时的影响更大;当河网提取阈值增加时,单位线峰值减小而退水段历时增加.在此基础上,依据敏感性分析,确定了较合理的河网提取阈值、河道流速和坡面流速,计算了每个子汇水区的洪水传播时间,制作了湘江流域县城子汇水区的洪水传播时间分布图.最后,将本文计算结果与湘江干流实测水位资料进行了对比分析,发现模拟结果与实测结果接近.本研究为洪水预警工作提供一种参考思路.Predicting travel time is an important part of flood warning.The central point of 51 county-level cities' build-up area in Xiangjiang River Basin was considered the outlet of subbasin county's catchment area was divided,instantaneous unit hydrograph was calculated,influence of hillslope velocity,channel velocity and of threshold area to extract river network on unit hydrograph was analyzed.Channel velocity was found to have a greater impact than hillslope velocity on the rising limb of flood.Hillslope velocity was found to have more obvious influence on duration time of flood than channel velocity.With increasing threshold area,the peak flow decreased and the time of recession limb became longer.The travel time of flood in every sub-catchment area was calculated,travel time distribution map of county's catchment area was made according to sensitivity analyses and literature.Comparison was made between calculation in this article and measured water level data in the main stream of Xiangjiang.Differences between the two were found to be within reasonable range.This work could provide some references for flood warning of watersheds.

关 键 词：流域提取 洪水传播时间 瞬时单位线 洪水预警 湘江流域 

分 类 号：P333[天文地球—水文科学]