摘要
空间单元糙率系数是二维GIS水动力演进模型FloodArea中的重要参数,对模拟过程中流速有显著影响.模型算法与模型糙率系数定义都没有区分河道与坡面的概念,将栅格单元皆视为坡面,坡面漫流与河道汇流规则统一利用曼宁公式定义,糙率系数通常根据土地覆盖类型静态设置.但在模拟过程中,汇流或洪水的演进过程往往会导致下垫面糙率降低,使模拟糙率较实际偏高,模拟流速较实际普遍偏低.针对上述问题,根据土地覆盖类型与DEM,提出了河道区域与坡面区域区分化处理的糙率设置方法.以福建木兰溪中下游仙游水文站到赖溪水文站河段为研究区,使用改进后的糙率系数结合FloodArea模型完成了基于实测数据的洪水模拟实验.结果表明,改进的方法简化了率定过程,提高了模拟精度.同时,改进的方法不需要额外增加数据资料,较适用于贫资料区的洪水演进过程模拟与灾害预警.
The space roughness coefficient is an important parameter in FloodArea,which is a two-dimensional GIS hydro-dynamic evolution model.The coefficient has a significant influence on the flow velocity in the simulation process.The al-gorithm of FloodArea and definition of roughness coefficient in the model,both regarding grids as the slope,do not distin-guish the river area and the slope area.Besides,rules of overland flow and channel flow are both defined by Manning for-mula.In addition,based on land cover type,roughness coefficient is usually staticly set.However,in the simulation,the process of confluence or flood often leads to lower roughness of the underlying surface,which makes the roughness of the simulation higher than the reality,and causes the lower flow rate in result.Aiming at the problems mentioned above,the method of setting up the roughness by differential treatment of the river area and the slope area is put forward based on the type of land cover and DEM.Taking the river between Xianyou hydrologic station and Lanxi hydrologic stations as study ar-ea,which is in the middle and lower reaches of Mulanxi river in Fujian province,this paper used the improved roughness coefficient and completed the flood simulation experiment by FloodArea based on the actually measured data.The results show that the calibration process is simplified and the accuracy of the simulation is improved.In addition,the method does not require additional data and is comparatively suitable to the flood hydrological process simulation and flood disaster warn-ing in the area with lack of data.
作者
罗尊骅
林广发
张容焱
张文富
LUO Zunhua;LIN Guangfa;ZHANG Rongyan;ZHANG Wenfu(Institute of Geography,Fujian Normal University,Fuzhou 350007,China;Fujian Provincial Engineering Research Center for Monitoring and Assessing Terrestrial Disasters,Fuzhou 350007,China;Research Center for National Geographical Condition Monitoring and Emergency Support in the Economic Zone on the West Side of the Taiwan Strait,Fuzhou 350007,China;Fujian Climate Center,Fuzhou 350001,China;Xiamen Great Power Geo Corporation,State Grid Information and Telecommunication Group,Xiamen 361008,China)
出处
《海南师范大学学报（自然科学版）》
CAS
2018年第1期98-104,共7页
Journal of Hainan Normal University（Natural Science）
基金
国家重点研发计划重点专项(2016YFC0502905)
福建省公益类科研院所专项(2015R1034-1)
福建省测绘地理信息局科技基金(2017JX03)
