Dhemaji, Dibrugarh, Lakhimpur and Sibsagar Districis of As$M. The
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See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/263471229 Extent of flood inundation and study of morphological changes in upper reaches of Brahmaputra river in the vicinity of proposed road and rail bridge site near Bogibilgaon Dibrugarh... Data · March 2000 CITATIONS READS 0 25 2 authors, including: Aniruddha Uniyal Remote Sensing Applications Centre, U.P. (RSAC-U.P.), Lucknow 75 PUBLICATIONS 121 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Space Based Information Support for Decentralised Planning-Update View project LiDAR Mapping Project View project All content following this page was uploaded by Aniruddha Uniyal on 30 June 2014. The user has requested enhancement of the downloaded file. EXTENTOF FLOODINUNDATION AND STUDY OF MORPHOLOGICALCHANGES IN UPPERREACHES OF BRAHMAPUTRARIVER IN THE VICINITYOF PROPPOSEDROAD AND RAIL BRIDGESITE NEARBOGIBILGAON. DIBRUGARH DISTRICT,ASSSAM USINGIRS DATA OF 1998 ANIRUDDHAUNryAL and PN. SHAH Renote SensingApplications Cenlre, LJ arPradesh,Luckitot' -2206 02l Bralmaputra river while descendingdown from ArunancchalHills to tie flat terrain of Assamexperiences sudden changes in gradientand acconrmodatesitself by formingan jnterlacingnetwork of anabranchesand braid bars. The typiccal braided natureof Bralmaputrariver is attributedto thechange in sedimentload{ischarge relationship due to tie suddenchanges in gradient.The high sediment load is deposiledwithin lhe rivercfiaffrel in the form ofbraid bars and on the banksbars in responseto the low carrying capacityof the river Additionally,Brahmaputra river'witnesses exceptionally heaty floodsduring monsoondue to healy rainsin its catchment.Satellite data provides synoptic arld monoscopic view of the terrain duringdifferent seasons/years and is an excellenttool for €mporal monitoringofchannel migration and bank erosion. The dlnamics ofbraidba.rs ard ex:tentsof flood inundationare also monitored,as theseare very importantconsiderations for any i developmentalproject in thisarea. Blahamputra river stretch in tie vicility ofBogibilgaon, Dibrugarhdistrict, Assam has been studied for assessingbank erosion and extent offlood inundation.This hasbeen undertalen principally to verify the feasibilityof proposedRail cum Road Bddge acrossBrahmaputra river at Bogibilgaoncornecting Dibrugarh and Dhemajidistricts of upperAssam. Satellitedata including IRS IC, LISSIII dataof 6thAuellst, 1998 and IRS ID, LISSIII daiao f 2nd No\ ember. I 99 8 havebeen visually inle ryrered and river configurarion maps thusgenerated hJve been analysed in orderto assessthe feasibility of Bogibilgaon-RajaPur bridgesite. Examinationof flood inundationmap of 6th August, 1998 illustrat€sttal Bralamputrariver andits tributaries viz. Sisi, Tangani, Sesa and Burhi Dihingwere srvollen.'_: dudngthe hea\y rainfallin August,1998 ard rvereinterlacing across the terrainin pansof..# Dhemaji,Dibrugarh, Lakhimpur and Sibsagar districis of As$m.The breachine of riffi ofthe river may culJninateinto a catastrophicflood, to aivert t}le riglt br.rk anabrancchesof Bralmaputrato an entirelynew course.The future flood scenarioof this kind across Bogibiigaon- Rajapur section sounds an alarmnot only to tle stabilityoftle northembark piersaid abutrnentsof tle proposedbridge but alsoto surroundingvillages viz. Sisi DigBalagaon,Barmuriagaon, Deurighat, Bargiuli ald Kulajangaon.It calls for the pro'per protectionof baik n€r Rajapurvillage to avoid ftequent breachinga:rd subsequen! back- I flow of water during future floods. In addition to the ballk €rosionand channelchanges ;, durirg floods, Ale stabilty ofbraid bars etc. are importantconsideration for the engineering ! projectofthis kind Owing to their high susc€ptibiliiyto erosionand frequentdisappearaice : and emergence,the braid bars are oneoi the mostdlramic landfom$associated with I Br&hanputrariver system_The d''namic nature ofbriad barsrenders them unsuitable to be usedas a soundfoundation for placingpiers and abutrnents_ The ext€nt ' offlood inundation ardB.ahamputla ver confguration changesin tle vicinity ofproposedbridge site aJrdtwo , .altEmativesites have also be€n studied using 1998 data The braidbars in tle vicinityof -. altemativesite-I i.e upstreamof Bogibiigaonare not stablebut the river in this areabas nor *ihessedback flow duringfloods, rvhereas mos! ofbraid ' barsare dlnamic in naturein the vicinitvof altemativesite - II i.e downstreamofBogibilgaon, but somebraid barshave vegetationciier alld are stabilisedin nature.Moreover, the rivei has witnessedvery little backflorv during the iloods of I 998 in this area.The studyreveals tliat alternarivesite-I & II areb€ner sites as comparcdto . thebridge site pryosed by fuTES. oao View publication stats.