Reckoning flood frequency and susceptibility area in the lower Brahmaputra floodplain using geospatial and hydrological approach  

作　　者：Pranab Dutta Sujit Deka 

机构地区：[1]1Department of Geography,Gauhati University,Jalukbari,Assam,India [2]Department of Geography,Bodoland University,Rangalikhata,Kokrajhar,BTR,Assam,India

出　　处：《River》2023年第3期384-401,共18页江河(英文)

摘　　要：Climate change has remarkably intensified the occurrence offloods around the globe.Flooding causes loss of life and property.Flood frequency analysis(FFA)is an important investigation and plays a key role inflood-related studies.Geographically,the study area is confined in the lower Brahmaputrafloodplains,flat slope,and rivers are braided in nature.Because of Heavy rainfall,major rivers in the area carry huge influxes of surged water during the summer period.Hence,disastrousflooding can be seen every year in the study region.The present study aims to modelflood frequency using the hydrological data to understand the effects within the area.FFA approaches like Gumbel,Log Pearson type 3(LP-3),and Log-Normal(LN)were used,and comparative analyses were done using water level data for the Manas,Aie,and Brahmaputra Rivers.Moreover,remote sensing and the geographic information system(GIS)environment were used to generate FFA-basedflood predictive inundation map at 5,10,50,100,and 200 years of return periods.Here,Gumbel's distribution has found the bestfit for all the rivers among the three.The distribution reveals that at a 200-year return period,the highest water level would be increased by 1.45,2.41,and 4 m for the Manas,Aie,and Brahmaputra Rivers,respectively.The study shows that almost 493.54 and 673.72 km^(2) of areas are expected to be submerged at 5 and 200-year return periods according to Gumbel's distribution;LP-3 distribution predicted 493.01 and 555.66 km^(2),and the log-normal distribution method predicted 432.51 and 555.74 km^(2) offlood-sensitive areas at 5 and 200-year return periods,respectively.The FFA highlighted spatio-temporal effects on the expansion of submerged areas.We hope that thefindings of the present study will aid in the differentflood hazard management strategies for future endeavors.

关 键 词：brahmaputrafloodplain flood frequency analysis gumbel LN LP-3 predicted inundation area susceptibility map 

分 类 号：TV1[水利工程]