Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. hneta ileaebt h iuto yicesn h iko odn n ae ogn.Ti will This logging. water and flooding of Staveren (van risk climate polders of the in consequences increasing the living the during of by people polders one of situation low-lying is millions the the (SLR) capacity affect rise of exacerbate conveyance directly level drainage water will Sea Also, load, that their problematic. levels. sediment increasingly change water decreasing the become within-channel flood channels, has carry massive higher from river season in to to rainy flow the resulted leading capacity transported water This and of lost is fresh monsoon reduced. year silting-up have of during dramatically per Bangladesh causing supply plain sediments SW delta decreasing deposition, of the of With sediment tons on rivers billion deposition 1999). the 1 sediment Ogawa, This about season, the while & total plain. dry in Yamaguchi, delta in during Begum, constructed the large: upstream (Islam, of were is aggradation sea polders natural delta the and 139 GBM Khan to mean floodplains the about & the above in embankments in tide, Warner, meters flow earthen flow high rising sediment sediment 1 Staveren, By the during than (van hampered 2016). less flooding 1970s but (CCC, initially, elevation AMSL from and an meters lowlands 1960s (SW) having 5 tidal below southwestern area late area the the of the protect of delta of 78% 21% to (GBM) and estimated Ganges-Brahmaputra-Meghna (AMSL) an level the with sea of flat zone is coastal Bangladesh elevation low The RSLR. counter to Introduction world the around deltas RSLR sinking than of the rate more to promising the land applied match a the to be elevate is opportunity potentially can provides polder can deposition therefore TRM the sediment TRM like the into delta. flooding as GBM flow controlled without delta the of the the than throughout Application regulating in RSLR. deposition regions of without total flow rate lower flooding yearly tide-dominated slightly the polder and but mixed re-establishing efficiency, region the that river-dominated trapping for than show increases strategy higher deposition results times polder sediment season 28 where Our a almost monsoon region into and tide-dominated with regulation. season), flow the Dry Regulating deposition of and reaches sediment Monsoon monsoon. the (Pre-monsoon, in along during seasons regimes seasonality largest three flow is all show mixed in TRM results highest and for is Simulation potential tide-dominated The river-dominated, sediment regulations. highest. of quantify the flow to conditions having model and under and hydromorphodynamic flow (‘beel’) numerical seasons river-dominated 2D section different for calibrated polder TRM for a apply re-opened of We applicability a assessed. potential in presents be the date, deposition (TRM) to To but Management yet regions, sections. River is polder Tidal coastal regimes re-opened (RSLR). flow tide-dominated in rise mixed to sedimentation level controlled applied through sea level been relative land has to the due TRM raising by 2100 losing RSLR by of combat land danger to habitable in opportunity are their an Bangladesh of within fourth delta one (GBM) to Ganges-Brahmaputra-Meghna the up of areas coastal populated densely The Abstract 2020 5, May 1 Islam Feroz Md Bangladesh southwest of the delta in Ganges-Brahmaputra-Meghna polders of potential flooding accumulation controlled sediment through of variability seasonal and Spatial teh University Utrecht 1 asMiddelkoop Hans , 1 alSchot Paul , 1 , 1 07.Teplesicesdfo productivity food increased polders The 2017). tfnDekker Stefan , tal. et 2017). , 1 n aprGriffioen Jasper and , 1 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. e 08.Peiu tde xlrdteeet ficesn ubro neso eietdpsto inside deposition sediment on inlets of number increasing Kawai- of & Nakagawa, effects Talchabhadel, 2012; the data Pramanik, explored historical & studies both Shampa by Previous 2013; studied 2018). Akram, controlled been ke, & applying has Rasul, by TRM Khan, rise Gain as Khan, level such (Amir, 2013; sea polders by Die, survival predicted of delivered above (de for re-opening sediment land of analysis vital sufficient elevate effect is with to TRM.The height world opportunity like delta an the flooding provides relative around earning this maintain deltas rivers, for to sinking the activities sedimentation For economic controlled timescales. Brown for multi-centennial and operated. over opportunities change is providing climate TRM by when to raised even sures year be the thus only round may Tatenhove, not alternative van livelihood stakeholders Staveren, will for (van by control and TRM TRM pest agriculture of natural for of operation as year act Seasonal sediments, the rich flooded. Warner of nutrient when & bring part such also for agriculture polder but available floating land a land the farming, re-opening the raise fish make through as will sedimentation such land controlled the livelihood with raise land to the TRM flooding as seasonal of potential The land (Gain the role. compensation of dominant proper stakeholders. use a without by the plays flooding TRM restricts beels prolonged years tide 12 Such several where to al. operation. for applied 2017) TRM et polder been during a Rouillard, activities has inside & economic TRM water Datta, for allowing then, continuously Rahman, Since Staveren of (TRM). Benson, van practice management (Gain, Current 2006; raised river Bangladesh runoff tidal (Adnan, beel SW as the dike surface water termed inside in the where was tidal surface of it land polders, re-allow re-opening river, the to plain tidal the and river, Bangladesh delta through adjacent al., SW deposited the the et sediment in from of inside the sediment dynamics polders parts of with tidal In lowest the removal Re-allowing substantially in 2014). of the 2009). resulted (Chakraborty, (Awal, one are channels beel congestion drainage of the Beels drainage internal dike 2006). the and the than through (Adnan, logging accumulates higher of water beel eventually re-opening prolonged become a have to in inside Bangladesh resulting led SW subsidence polder this of yearly the 1997, beds of channel inside rate ongoing river land as of the the out indicative siltation, carried range. progressive is be wide to study with to rate Due The uncertainty needs the mm/year. with large study of 3.4 has mm/year, detailed median now of However, 43.8 till the variation delta. to presented standard calculated GBM mm/year the with (2015) -1.1 in mm/year Nicholls subsidence 2.9 from and as Brown range variation. subsidence rates of temporal subsidence and Reported low-lying spatial of studies. considerable 4.5 vulnerability have previous the to from increase emission will delta (Brown carbon subsidence a SLR global and in starvation to considers Sediment decade deltas scenario 2300. each AMP4.5 by warming scenario. preindustrial surface AMP4.5 above future for to 2050 in respond by and future SLR but m which Nicholls, in now and Brown, (Goodwin targets, warming determined policy-driven manner Haigh, fully global to self-adjusting warming not on Goodwin, future are (AMP) restrict scale. Pathway reductions to regional scenarios Mitigation emissions considered at Adjusting are of AMPs projection future. effect the the the of analyzed uncertainty (2018) the Matter to adds which (Oppenheimer (Oppenheimer 2015 2050 to al. by 2005 et range) of likely period m, the (0.23–0.40 (Oppenheimer over 8.5 mm/year RCP 3.6 under by that m risen indicated has (IPCC) (GMSL) al. Change level et Climate sea on mean Panel Intergovernmental global observations, the altimetry habitable its and of gauges km fourth tide 47,150 V one over (Ericson, to has rise up level Bangladesh loosing sea of of to danger due 2100 in by now land is delta (GBM) Ganges-Brahmaputra-Meghna The 09.GS speitdt iebten02 ne C . 01–.2m ieyrne n 0.32 and range) likely m, (0.17–0.32 2.6 RCP under m 0.24 between rise to predicted is GMSL 2019). , 07,adosre nvnsdmn eoiinwti h el a usindteacpaiiyof acceptability the questioned has beels the within deposition sediment uneven observed and 2017), , 09.Salvlrs sntgoal nfr n aisrgoal swl (Oppenheimer well as regionally varies and uniform globally not is rise level Sea 2019). , 07.A hsitreto a rmrl ple orti h riaecpct n aiaiiyof navigability and capacity drainage the retain to applied primarily was intervention this As 2017). , 08 n vi h adfreooi ciiisdrn h eann esn.Teacceptability The seasons. remaining the during activities economic for land the avail and 2018) tal. et 09.“iey eoe h ieiodo notoeo euti 610 (Oppenheimer 66-100% is result or outcome an of likelihood the denotes “likely” 2019). , tal. et 08.BonadNcol 21)smaie 0 usdnedt nGBM on data subsidence 205 summarized (2015) Nicholls and Brown 2018). , tal. et tal. et 2 raadpplto f3.2mlini h er21 CC 06.From 2016). (CCC, 2011 year the in million 38.52 of population and area 07 a Staveren van 2017; , 08.Goodwin 2018). , ¨ or sat,Dnmn ad ebc,20) h osa zone coastal The 2006). Meybeck, & Ward, Dingman, ¨ osmarty, 2 tal. et tal., et 21)poetdtesalvlrs ob 0.21 be to rise level sea the projected (2018) tal. et 07 n ahmtclmdlsimulations model mathematical and 2017) 21)sae httemtgto mea- mitigation the that stated (2018) tal. et 09 ihmdu confidence medium with 2019) , tal. et ° warming C 2019) , Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. o n ie o.Tetdlflopani dnie stergo ftd-oiae o eie h area the regime, flow tide-dominated of region the as identified tide-dominated is flow, river-dominated floodplain regimes: tidal flow own The their flow. with mixed regions high Wilson and three to and in flow due area (1985) FAO study seasonally by the flooded defined divided We become area that tide-affected tidal during The areas flooding and those monsoon. to during floodplain al. floodplain subject specially river study et river rivers being as the the creeks, of and as in and of defined season, extent level rivers (1990) dry water part tidal The Brammer in numerous southern (1990). tide. even of Rivers, Brammer the tide consist high Padma by that high in depicted to the areas were located those due and Bangladesh floodplain of flats primarily Ganges tidal areas tidal but the coastal the The well, from for delta. as water floodplain the flooding flood in in of experience flow volumes flooding FAOarea by river large wide-spread areas The receive causes affected rivers flow. which tide the water as designated monsoon fresh water were of During of and season reversal dry part sources experiencing during western areas primary tide the Wilson The the to and in south.. due River (1985) the are about (BBS, tide) from Gorai is part (BBS) (horizontal entering The direction area tides Statistics eastern area. flow by study study of the affected the the Bureau is in of Bangladesh of international Bangladesh River part southwest the population by Khan southern and The conducted the Arial south in 1). census the the located in recent (Figure are Bengal west the Polders of the to 2012). Bay in according east, the India million in and 38.52 River Bangladesh Meghna between north, the border in km River Padma 41,900 and the covers study The area Study be to considered are Methods regime like flow flooding each controlled of for southwest of locations the applicability selected in regions. the regimes respective for investigate flow the utilized mixed to of variables representative and scale input river-dominated delta by The the characterized Bangladesh. regions at different study across exploratory TRM efficiency. an trapping is and polder This conditions. deposition of located total boundary TRM regulation affect ongoing different an conditions and is these boundary which seasons, Pakhimara, these comprise sediment Beel different for that resulting (Islam model for river- flow SW-Bangladesh scenarios the hydrodynamic rivers, in from 2D developed investigating feeding model gradient we by calibrated the a a delta purpose, Using of along GBM this regimes polders For the flow of inundation. across different flooding regime for controlled flow deposition seasonal TRM-like tide-dominated strong controls of to a major applicability dominated show are the and range investigate 2019), tidal We and Griffioen, SSC & since Dekker, 2017). of regime, Schot, seasonality 2010; flow of Middelkoop, (IWM, different branches effect variability (Islam, river The these feeding deposition delta. for the sediment GBM efficiency in well the their of (SSC) as across concentrations delta, investigated regimes sediment the of flow suspended be throughout potential of associated should range land the and wider evaluate ranges the a To tidal raise sub- for flow, regime. to river first surface flow explored polders mixed land be of and to polder flooding river-dominated needs the controlled a raise of with strategies can sections TRM-like deposition river along sediment polders resulting dominated for (Gain the cases. tide- unevenly studied that a all from but indicated water for stantially polder sediment-rich increase re-allowing a increase elevation by into to land flooding was river in controlled TRM of time applications same of TRM the objective Previous at primary resulted the it Although prism, River tide-dominated. Tekka-Hari-Kobadak-Shibsa tidal the is the within which polders Bangladesh), the inside (SW canals reach of use compartmentalization, beel, the 21)oelp h otenpr ftervrflopandlnae yBamr(90 Fgr 1). (Figure (1990) Brammer by delineated floodplain river the of part southern the overlaps (2017) tal. et (2017). tal. et 09,w iuae eietdpsto o hs cnro odtriehow determine to scenarios these for deposition sediment simulated we 2019), al. et 2 otws ato B et fBnlds,buddb agsRiver Ganges by bounded Bangladesh, of delta GBM of part southwest 07.Yt otoldtmoayfloighsntbe investigated been not has flooding temporary controlled Yet, 2017). , 3 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. fdshreadSCwr vial nyfrsotproso ie ra reua ieitras h average The intervals. time irregular at or and time, of reports periods measurements as short continuous for well but only locations., available as representative were all (CEGIS), SSC for and Services available discharge were Information of data level Geographic Modelling water Water and Hourly of Environmental papers. Institute for as such Center Plan- institutes sedi- Resources research (IWM), Water suspended non-governmental collected (BWDB), and and were Board (WARPO) level, Development data Organization Water water Available Bangladesh ning discharge, 1). as river (Figure such collected of agencies were governmental series locations from time representative regimes, at flow (SSC) different concentration ment of regions the three in all For m 1.45 analysis to and monsoon from tide during collection coming by m water Data 0.3 affected flood from is the varies region to 2 flow due location 4). mixed as damped at (Figure The are used range period 1). ranges tidal were pre-monsoon (Figure Average tidal River) hydro-morphodynamic regime 2). monsoon Nabaganga The (Figure flow during 1). on upstream mixed although (Figure BWDB the seasons, regime of under all flow station during mixed modeling north measurement of the km (“Gazirhat” region for 150 the 2 about input is within Location which 5 lies reach at and River about conditions Gorai-Nabaganga-Pasur shore, and the sea of season the the section pre-monsoon during from the varies Salinity is the rises River 4). River Pasur 2016). during Nabaganga Figure Roy, Pasur the The meter) and & of the 2 Kumar, per level (Figure of (Ghosh, (deci-siemens m water flow monsoon 2 ds/m mean in about The the 20 ds/m of used 1). still, range about were (Figure tidal 2); between average reach) regime (Figure an seasonally River year flow experiencing Pasur the still tide-dominated the then around the monsoon, on tides under BWDB by modeling of dominated the is station hydro-morphodynamic The for measurement the 1). (Figure (“Mongla” meets input regime and flow 3 as system tide-dominated Location of River region Gorai-Nabaganga-Pasur at the river-dominated the in conditions of lies the Pasur section under The downstream south. modeling most in sea the the is for River input Pasur as The Development 1) Water represents (Figure Bangladesh hydro-morphodynamic reach) River of the River Gorai station regime. used Gorai During upper measurement flow we the seasons. The Bridge” on Therefore, Railway pre-monsoon 2). (BWDB) monsoon. (“Gorai and (Figure Board during 1 dry tides Location regime the of at flow during effect the conditions river-dominated the 2) over large of level nullifies discharges (Figure water region discharge but tides The the season, river 3). the dry high (Figure and bsy the 2015) the River influenced in Saadat, Pasur monsoon flow is & as water Rahman, River downstream (Moly, fresh Gorai monsoon further little entire the km very during 300 has downstream water km Gorai about of 50 The sea amounts about 1). at the River (Figure reaches Ganges branches Gorai from and other The bifurcation border, its 1). has Bangladesh-India (Figure River, study the Ganges this of the for of selected distributary was a Bangladesh is and SW June River of rainfall October). in reach these to River highest combining Gorai-Nabaganga-Pasur (June The by is monsoon average defined L´az´ar rainfall and the were by May) that area and to made study indicate 3) (March suggestions the Figure 3) pre-monsoon the for 2017; Figure Seasons with Mallik, 2017; August. data & in (IWM, discharge (Arefin regime highest branch 2015 is flow River flow to discharge river-dominated Gorai tide-dominated and 1901 of years of of region the region discharge the for the monthly within rainfall within none monthly lie and average polders regime The flow the mixed of regimes, of Most 10 flow respectively. 1). region about tide-dominated (Figure are AMSL, the (SRTM) and in m Mission flow few Topography 1.7 (Figure Radar mixed regime, and regime Shuttle flow, m flow from tide-dominated river-dominated 2.2 our collected - region of data m, for 3 as elevation location region and remaining the representative the regime, using and a flow calculated of regime selected mixed flow elevation we - mixed Average 2 region of regime, each 1). region flow Within as river-dominated 1). defined 1- (Figure analyses: is regime tide flow by river-dominated affected of but floodplain river with tal. et 4 21)it r esn(oebrt February), to (November season dry into (2015) Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. h ie-oiae n h iedmntdrgo,tewtrlvl sdfrlcto ersnigriver- between location representing level at 1 level land water location ( the in for between 3 difference difference used location mean the levels inves- The and water for to accordingly. 1 variables the shifted compensate vertically input region, To were as region tide-dominated dominated used regions. the regions. were different and different regimes for river-dominated of flow scenarios the dynamics different developed sediment representing the the SSC simulate to and tigate used level was water Pakhimara variant Beel Time for model calibrated The development data. simulated Scenario and respectively. observed 0.84, respectively the 0.0005 18.3, between and of and agreement 0.88 16.6 velocity good 9.7, 0.87, in settling were were resulted concentration and concentration model sediment N/m2 and sediment 0.08 discharge and level, of discharge water (Islam average stress for spatial level, For (%) shear water NRMSE variables. by s/m1/3, for The input calculated 0.032 R2 different were the of the (NRMSE) for coefficient error m/s, data model, square Manning’s the observed of mean the of uncertainty with root the value N/m2 understand results normalized To 0.01 modelled the from m/s. the and stress 0.001 comparing to (R2) shear m/s s/m1/3, determination 0.0001 0.01 was of from to model velocity coefficient s/m1/3 settling the 0.1 and of N/m2 from analysis 0.1 coefficient Sensitivity to Manning’s varying model. with morphodynamic out with and SSC carried hydrodynamic and discharge calibrating level, for water observed parameters the comparing (Islam by Pakhimara ones Beel simulated for ( calibrated calculation was seasonality model the and The reduce regime flow to different plain of flood about scenarios the of the ( 5 for to area and accordance used (cell in 4 was canal cells adapted 2, m2) inlet 2D were 5000 the that the to represent SSC, where up to and used area opted was was (cell size (Islam mesh mesh cell intensity Finer coarser flexible and with octagon. m2) mesh to 170 scheme a triangle Pakhimara, from QUICKEST net Beel shapes the to of had according bathymetry on step the based time represent third-order each To is the for 2012a). which updated using (DHI, is solved scheme, mesh bathymetry 2012b). ULTIMATE is 2D the (DHI, the simulation, ADE the sedimentation morphological of The For as cell (ADE). 2012b). known the equation (DHI, of scheme, advection-dispersion interface approximate difference the the an uses at finite uses three-dimensional fluxes module model of convective MT solution The the the The calculate 2012a). on sediment to based (DHI, cohesive solver calculated equations calculating Riemann are Navier-Stokes for 21FM averaged Mike used Reynolds of was incompressible processes 21FM (HD) Mike hydrodynamic The of module 63 than transport) (less (mud fine 2012a). MT transport. is (DHI, hydro- the sediment simultaneously in the simulated numerical 2010), TRM are of IWM, two-dimensional re-opened active transport size an sediment a grain a and is the into used which processes As hydrodynamic flow Pakhimara, we which Beel of TRM, in for DHI) regulation with calibrated and and beel (Islam developed seasonality Bangladesh a southwest was regimes, inside that flow model sedimentation morphodynamic different on of section effects polder the three understand for To seasons model three during hydro-morphodynamic locations SSC selected of average the Setup and at range regimes tidal flow mean different data, the rainfall calculated. these monthly for were From average regimes hydrographs 2. and flow annual River Figure Ganges The in the shown 3. from are Figure bifurcation the in at presented River are Gorai the of discharge monthly iue1 Figure tal. et ). .Teeiptvralswr rvddfrLctos1 n ihrsett hi o regime flow their to respect with 3 and 2 1, Locations for provided were variables input These ). 09.Tecluae odeso tfrtedvlpdmdlidctsta h calibrated the that indicates model developed the for fit of goodness calculated The 2019). , tal. et iue1 Figure 09.Froraayi esple h oe o elPkiaawt ae levels water with Pakhimara Beel for model the supplied we analysis our For 2019). , tal. et 09.Mnigscecet ha tesadstln eoiywr h primary the were velocity settling and stress shear coefficient, Manning’s 2019). , uigdysao a acltda .3m h ae ee flcto was 1 location of level water The m. 1.03 as calculated was season dry during ) tal. et 09.Mdlsmltoswr are u sn ie2F dvlpdby (developed 21FM Mike using out carried were simulations Model 2019). 5 μ )frtesuyae Dta&Sbaain 1997; Subramanian, & (Datta area study the for m) Figure Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. xrce rmtemdlsmlto.Tedffrnebtenteicmn n ugigsdmn odat retained. load load sediment inlets sediment outgoing the as and considered at was incoming SSC incoming period the and Total simulation between discharge entire difference water 2017). the The the Middelkoop, over It entire using inlets & simulation. the calculated the over model retained. Sloff, were deposited the sediment Perk, retained or from SSC and der load retained extracted van of beel sediment is seasonality that Deijl, and the sediment of load der inside suspended sediment effect van delivered incoming (Verschelling, the sediment the period understand of of fraction simulation quantity to and the the scenarios as simulation on the defined of was all regime days flow for 14 different calculated representative and was season. the a efficiency from over in trapping calculated days deposition The was of was sediment number scenarios seasons total of different developed the for mass the for deposition all total scaled Sediment for the models. season using hydro-morphodynamic the various estimated over the deposition of simulations sediment the of mass total The scenarios simulated the of Analysis dominated Tide Flow Mixed dominated River Regime Flow regimes, regime flow flow combining and seasonality by regulation, scenarios flow developed the the The considering that matrix hour. Scenario assumed was 1 operation 1: in in Table it gates require gate presented The Therefore, This will are gate. regulations gate other. consuming. flow same the the time and the of seasonality through through is draining closing beel operation and and the and filling leaves opening operated, instead and manually beel (Islam (Islam inlet, the are closed inlets one across and Bangladesh both through throughflow open for ensure enters alternatingly different time to are flow Two gates aims same the their the water. case inlets, at stagnant that two closed the of In flow and operation from no opened gate (Islam settle so, successive are successive doing to the and gates By sediment simultaneous both hours. the considered: operation, 12 allowing were following gate flow hours operation the regulated 12 for gate the closed for of were for rules occurs and rules beel beel beel operation the the the gate enter into inside beel, to schemes water the sediment-rich regulation into of flow flow Islam flow unregulated and from simulated to adopted seasonality tide the were addition regimes, neap that scenarios In flow assumed and varying polder. was spring the by It of within defined locations. effect were three scenarios the locations, all The three capture seasons. for all the to scenarios of in consecutive consistent representative continuously have days are available to 14 periods not and model for was season the out data for each variables carried As for input tide-dominated were generate and unavailable. to simulations river-dominated were used between model data were difference (2017) SSC level IWM measured in land presented when the curves for rating Sediment compensate to region. m 1.03 by lowered Seasons Seasons Seasons tal. et 21) n rbt ae eandoe o 2hust lo the allow to hours 12 for open remained gates both or one (2019): r r Dry Dry Monsoon Dry Dry Monsoon Pre-monsoon Monsoon Dry Monsoon Pre-monsoon Pre-monsoon Monsoon Dry Dry Pre-monsoon Monsoon Pre-monsoon Monsoon Pre-monsoon Dry Simultaneous Monsoon Pre-monsoon Pre-monsoon Dry Monsoon Pre-monsoon Open Regulations Flow al 1. Table 6 gates Regulations Flow tal. et 09.Frsimultaneous For 2019). , tal. et gates Successive Regulations Flow tal. et 09.For 2019). , 2019). , Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. ieto Fgr ) aiu rpigecece o neuae o r o:aot6 tteloca- the at 6% about low: are downstream flow a in unregulated increases for and regimes efficiencies effi- flow trapping Trapping all regime Maximum for flow highest season. is tide-dominated 4). pre-monsoon range to (Figure tidal river-dominated trapping the mean direction flow from during the river-dominated gradient pre-monsoon when lowest trapping of the pre-monsoon regime, the and along location during flow during gradually the monsoon tide-dominated increases at highest during and However, generally are flow highest ciency well. mixed regime generally as of flow season is locations tidal monsoon for efficiency the during and At more high flow trap- season. is 45% Generally, mixed dry efficiency about 7). the of during (Figure and locations variability lowest regime, the and seasonal display flow at modelling efficiencies mixed the ping the from than of calculated deposition efficiencies location more Trapping 19% the about at in (Figure regime. results gates deposition flow polder successive sediment tide-dominated re-opened higher with the in into flow results and flow polder tide-dominated regulated unregulated the re-opened monsoon, of the During location 18% into the about flow 6). for in Conversely, unregulated results regimes operation period. flow gate monsoon simulations successive mixed 28 the Model using almost during 6). that polder. deposition regime (Figure and the sediment flow season within river-dominated seasons, more deposition of monsoon all sediment location during affects the for deposition regime polder for regimes show flow sediment re-opened the flow river-dominated total into the the flow The of of mixed among Regulation regime. location of highest flow the location is the at tide-dominated regime at than of tons tide-dominated higher location 100,200 times of the about location flow, at river-dominated the tons of at 129,800 location unregulated about the with and at deposition sediment tons flow total 4,600 monsoon, deposi- regime, about During sediment river-dominated is total substantially. calculated flow increases the dry the seasons three regime, for 6). the all flow (Figure higher for tide-dominated during tion to regime times than river-dominated flow from ten higher mixed gradient the is the 50% Along for it almost higher whereas is times regime, monsoon 40 and flow almost during river-dominated tide-dominated tide- and the deposition the the for sediment For than for The 6). smaller season (Figure locations, is season all regimes. accumulation At monsoon flow sediment the 6). the in over mixed (Figure during variation regimes deposition highest flow seasonal is all sediment regime, for seasons total season dominated the estimated per over varies that accumulation polder sediment re-opened demonstrate seasons the total flow results the of over mixed beel The accumulation the sediment of efficiency. inside total season reaches the trapping for The the compared are for 5). 5). scenarios -dominated and (Figure model Figure different tide season the and monsoon of the range 4 results the tidal in The (Figure during regime, transect pre-monsoon SSC tide-dominated average the during to highest along river-dominated highest river-dominated the gradually from of experience is change gradient reaches SSC SSC the the average Along average in and the 5). monsoon (Figure regime whereas during flow sections highest regime, tide-dominated regime is the flow and under mixed SSC mixed monsoon the reaches average under and the during the reaches in lowest seasonality, in cm with the occurs 20 regimes cm Considering reaches about 90 flow is about the all lowest of for variation in the and highest seasonally across varies regime, smallest The reaches varies also flow all is range season. range for tidal pre-monsoon level Tidal seasons during Mean water monsoon highest 4). monsoon. during mean (Figure and smallest season in delta and dry with GBM variation pre-monsoon between flow reaches during seasonal m between flow largest The three m 1 contrast, being tide-dominated 5 about seasonally, all In about 4). being to being of flow, (Figure level regime tide-dominated water reaches season monsoon. under mean flow pre-monsoon for and of river-dominated variation during season monsoon seasonal The from mildest largest dry during the and gradient have highest 4). level tide- regime monsoon level flow and water (Figure during to river-dominated water Mean flow season steepest river-dominated The tide-dominated is dry from seasons. regime to during hydrological gradient 4). flow lowest main the (Figure river-dominated is three along regimes with the level range reaches for water tidal the delta mean and from GBM level the decreases across water gradually regime mean flow the dominated shows 4 Figure Results 7 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. oso esn(iue6.I a eifre httd-rvndiyspl ffehsdmn oad the towards sediment fresh of supply lowest daily during in tide-driven regimes results sequence that flow SSC inferred tidal other lower daily, be to with can a compared combined sediments, It drive regime This fresh to flow 6). with river-dominated 4). unable (Figure re-supplied of (Figure is season daily location polder (which monsoon not the the mixed monsoon for is within the during deposition outflow beel to variation sediment and receding the compared tidal with inflow Here, when slowly small water leaves river very of monsoon. and feeding is beel during 4) the the there river enters (Figure in since sediment the range (Figure 5) flow in tidal river-dominated largest, (Figure discharge of the mean lower is location peak highest slightly the deposition to At is result sediment Due which monsoon, SSC region. flow during 5) average 6). region (Figure though highest flow (Figure SSC the even tide-dominated regions by higher 6) the characterized flow relatively of is all and reaches – for 2016) the monsoon in Cho, deposition - a & sediment season during longest Shaha beel highest The the 2006; in inside (Sarker, season. deposition discharge that sediment than of water total length river higher The the even factors. on region, of depends combination flow season a mixed sediments on the driven depends tide in deposition 5). Total location and monsoon (Figure rivers 5, region during slightly upstream (Figure flow SSC into the region tide-dominated highest resulting in flow the in loads 5), tide-dominated for sediment results Figure the high inland and in of towards the 2 seasons effect brought (Figure for cumulative dry the sea the than and for discharge Moreover, the water pre-monsoon regime larger from load 3). higher during flow is inland with sediment than monsoon, pushed tide-dominated beel larger SSC during is much the and lower Still, sediment a inside flow 4-6). less tides deposition (Figure mixed upstream, the regions sediment from of flow to Accordingly, tide-dominated locations (Figure due and 4). water regions flow the seasons mixed flow of (Figure at all outflow mixed regime in beels and and flow is the inflow- tide-dominated river-dominated rivers daily into the feeding and in transferred the SSC than in is higher region SSC With Haq, flow the & Consequently, river-dominated (Milliman Pasur 5). sediment the 2013). estuaries the the western in Mondal, of than the higher lower & estuary towards much much Ganges the Jr, is the through west Goodbred from the as river Rogers, in such Gorai estuaries 1996; west, the the via the re-enters Estuary. estuary transferred that in directly Meghna Meghna that estuaries load sediment the the the of through The re-enters via amount discharged The Bengal sediment tides. sea of River. the of the re- Gulf by part reach by sea eastern that the Meghna, the indicated deposition from into (2016) and sediment delivered Rahman Consequently, Brahmaputra sediment & rivers the Ganges, Sumaiya, the 4). on Haque, Bangladesh, specially (Figure depends tide, of season Gorai the rivers dry by the the primary influenced as available during are such rivers polders delta the the upstream, GBM opening in the from within load flow reaches sediment river river larger all lacking (Figure a season, level to dry polders. water contributing tide- the river the all During increased to of 5), discharge, flow, flooding river-dominated (Figure high overland by rivers from in excess deposition the results causes sediment gradient in This rainfall for the SSC heavy areas. higher monsoon along upstream and During in and 2) 5). erosion seasonally Figure land and vary and 4 flood SSC regards (Figure with and region effective flow range is dominated RSLR. practice regula- tidal combat management gate to level, water and deposition Water SSC such sediment regimes, where by these regions from elevation by the gradient land controlled identify the increasing is to to delta along GBM supports polders the This re-opened in in tion. regimes flow deposition tidal sediment to how river-dominated demonstrate simulations model The a within settle. water to flood sediment the the Discussion of of proportion trapping larger temporary a the regimes to that flow leads mixed demonstrates indeed and This regulation tide-dominated For gate times. trapping by flow. 4 increases flow beel unregulated the about monsoon For tide-dominated to is during compared of 7). increase polder when (Figure location seasons times this re-opened the and 5 the regions at into about the flow 13% by all efficiency of and for regulation flow efficiency regime trapping mixed flow the of river-dominated increases flow location of the Regulation at regime. 10% river-dominated, of tion 8 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. oesadOeem(07 niaeta nteGMdlateardto aeb eietto a be Amir can findings. sedimentation our with by agreement rate in is agredation This the Gain rise. delta level (2013); sea GBM Die, local de the of rate (2013); in average estimated that 0.5 the about indicate within than as more (2017) beel estimated Overeem the are and into regions respectively. Rogers flow flow sediment mm, tide-dominated through unregulated 14.3 elevation and by and flow land mm season We mixed in 11 monsoon flow, change considered, RCP8.5. mm, river-dominated the the are for for calculate during year mm/year polder to deposition per 10 the delta sediment rate and GBM subsidence The AMP4.5 kg/m for the 1300 for (2017) deposition. as of When Overeem mm/year floodplain median and 7.6 the mm/year. the Rogers in from 3.4 varies sediments and and ranges the of which year of (RSLR) variation mm/year density per 205 SLR the standard SLR 43.8 consider of relative and of to of compiled mm/year rate mm/year rate (2015) 2.9 the -1.1 Nicholls the as for from and median trend ranges Brown the linear by subsidence a with delta of temporally GBM rate and of the spatially subsidence that on (Oppenheimer indicates study 2015 literatures the The to (Oppenheimer that 2050 2005 scenario. indicates by of AMP4.5 range) IPCC period likely Climate”, the m, over (0.23–0.40 Changing (Oppenheimer mm/year 8.5 a RCP 3.6 in under by of feeding m Cryosphere risen location the and has the to (GMSL) Ocean at al. returns level monsoon the during sea sediment on lowest mean more is Report global velocity, range “Special tidal receding gate the the higher simultaneous deposition. as In which sediment to for polder, with lower the Due gate time in in successive resulting same settle the instance. regime, than the can river-dominated for an higher it at the is deposition at before open beel at which sediment open the river monsoon gates larger inside is during in both flow gate opposite receding results With is of one obviously velocity because effect This average regime. the gate, the However, flow successive one. operation, river-dominated regime. the of flow of with instead mixed than time location and operation same regime gate the flow simultaneous tide-dominated at with open delivered inlets be two efficiency portion trapping large can highest a sediment the velocity, even 30%. The More settling as about low tide water. is with sthis flood recedes regulation to and of flow Due 63 suspension recession with in than 1994). the stays achieved (less Moore, beel with fine & the slowly entering very Miller, it sediments is Kuehl, of leaves Bangladesh (Barua, and during SW cm/s) river sediment small 0.05 of Instead, the very rivers (about in beel. is the level the by regime into regulation water carried delivered flow without high sediment sediments river-dominated for of with opening cyclicity effect the beel closed and beel opposite for dynamics the are of the tidal enters range inlets no time has tidal is scheme the double there The regulation with because hence The same monsoon; regulations beel regime. the 2.4). flow Remarkably, flow the section with river-dominated deposition. is inside (see time sediment the resupplied deposition order the higher sediment daily cyclic in of results hours is total half sediment is efficiency, 12 sediment only and in trapping beel suspended water opened the higher inlets, of enter and the unregulated time can of with residence Sediment spite because the tides. in is because However, This efficiency, although trapping increases. less. 7), higher beel (Figure water. a the regime incoming of in inside flow the This location results of river-dominated the 6). SSC regulation of at lower (Figure Flow location to undisturbed deposition due the sediment mostly lower for of is is rate efficiency beel beel deposition (Figure and the river trapping total the the time inside highest inside in sediment residence water in retained of the flood results water delivery increasing of daily of recession regime mixed gradual larger volume river-dominated and and a the the dynamics flow in tidal monsoon, tide-dominated results of during of absence range the 2) tidal locations of larger the Because translates the for rivers 4). as (Figure feeder pre-monsoon average 7) the during lowest (Figure regimes. in highest regime of flow season flow is different effect dry representing efficiency combined during locations trapping The 2016) three The Cho, all deposition. for & sediment deposition (Shaha sediment discharge higher lowest water for to and essential 5) is (Figure polder SSC the within beel 09.GS speitdt iebten02 ne C . 01–.2m ieyrne n 0.32 and range) likely m, (0.17–0.32 2.6 RCP under m 0.24 between rise to predicted is GMSL 2019). , tal. et 09.Goodwin 2019). , tal. et 21) hmaadPaai 21) Talchabhadel (2012); Pramanik and Shampa (2017); , tal. et 21)poetdtesalvlrs ob .1mb 00for 2050 by m 0.21 be to rise level sea the projected (2018) 9 3 ugse yAlsnadKpl (2001) Kepple and Allison by suggested tal. et μ 09 ihmdu confidence medium with 2019) , )hvn o etigvelocity settling low having m) tal. et 21) van (2018); tal. et et Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. rnhsars h et,adapyn ieetflwrglto prtosfrteple.Orscenario Our polder. the for operations regulation flow river in different range applying tidal that: the and and demonstrate in (SSC) delta, analyses represent- concentration raise analyses the sediment land scenario suspended across and out discharge, deposition branches carried river sediment we variability seasonal purpose re-establish this the to For ing polders delta. of (GBM) re-opening Ganges-Brahmaputra-Megna of SW potential the explored We region Conclusion larger the for monsoon SLR effective in with TRM However, even making SLR m. upstream relative 7 is to shift about due considered regime presumably of future. flooded will subsidence flow reaches the be regimes of river river-dominated in not flow the rate for areas will mixed along the elevation it and level that as land water tide-dominated asumed well highest average projected of be of as overcome the safely average SLR to can As the of it height with AMSL, rate range. the m the the wide mainntain 10 However, re-opening and about to by uncertainly scenario. are polders flooding large case polders for the controlled the have worst flooding assist 1), all the controlled potentially (Figure As that for region can shows region. RSLR flow flow estimation monsoon mixed mixed Our during and and RSLR. polder dominated region the tide flow to they However, for rise tide-dominated sedimentation. potential level within with high land level has of land accumulation rate the sediment raises the TRM compare with not polder did the inside sediments allowing that Staveren • • • • • ie-oiae o einbcueteaeaeln lvto saot1 MLwt vrg of average with AMSL for m flooding 10 induce not about with will is 2015) RSLR rise. elevation Nicholls, that land level assumed & average sea safely (Brown the be relative (Oppenheimer range because can and region low wide projected It flow region relatively and variation. of river-dominated uncertainty flow is temporal rate large and mixed 2050 have spatial highest for for large RSLR the elevation SLR region. in than land flow projected included tide-dominated of of more subsidence and uncertainty increment is region the an that flow Although in mixed region the results flow it within deposition Thus, tide-dominated situated sediment monsoon. are total in delta the deposition. with even The GBM sediment in regions effect of increase the tidal deposition to polders for means experience sediment All monsoon effective which total during an regimes potentially deposition affects flow is sediment mixed considerably highest and during polder in flow SSC results tide-dominated re-opened tide-dominated lower flow with slightly the Unregulated reaches only into the polder. with flow in along polders and of range discharge the Regulation tidal river in highest when deposition The season sediment dry regime. highest lowest. during to is lowest discharge translates river and river deposition monsoon rivers, feeder highest sediment with feeder the deposition larger to the in in owing sediment in SSC monsoon result and SSC during range dynamics higher highest tidal is relatively sediment and deposition and sediment SSC the Sediment discharge, govern of polder. river river variation seasons. the in all inside the seasonal Increase in in the polder. effect discharge region the tidal and inside tide-dominated strong river by SSC the the Highest to range, In deposition due delta. riversTidal sediment small, the GBM surface. remarkably in the Highest land load is of sediment polder deposition highest reaches provides the regions. all season raising monsoon flow for during for season all SSC higher monsoon in relatively making during and inland evident discharge occurs shift polder is presumably the deposition will river-dominatedre-opening future. sediment regime of the flow flow of tide-dominated reaches in of tide-dominated areas the Seasonality reaches larger with along the for region along polders effective higher the much in TRM SLR is than TRM With higher for potential times regions. the tide- Along 28 sediment Therefore, a with total be operation. regime. reaches the flow can TRM the regime, along regime of flow polders flow polder within (south) dominated accumulation a tide-dominated Sediment inside to considerably. increases deposition (north) deposition sediment river-dominated from of gradient controls the primary are regimes Flow tal., et 21)ivsiae h odr ln h ie ece ihtd-oiae o n inferred and flow tide-dominated with reaches river the along polders the investigated (2017) 10 tal. et 2019), , Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. agaehBra fSaitc BS.(02.Pplto ess21.aalbeat: available 2011. Census Population (2012). (BBS). Statistics of Bureau http://www.bbs.gov.bd/Census2011/Khulna/Khulna/Khulna policy and adaptation Bangladesh over- local Bangladesh: technical of A region Bangladesh: coastal south-western in in options. pollution logging Water water (2014). of A. M. causes Awal, and sediment Sources river Tidal (2018). Ganges- (2013). A. the F. Mallik, view. Akram, & of & A., G., M. plain M. Arefin, Rasul, delta K., M. lower Engineering Gange- Geophysical M. du Khan, the Bangladesh. and Geological southwestern A., Ecological, delta to S. in M. study le supply Khan, case dans I., management-A sediment I. inondations S. Modern M. les Amir, (2001). contre E. lutte Bangladesh. in Kepple, de River Brahmaputra politique & la M., de Allison, retrait Le Bangladesh. au Brahmapoutre (2006). S. Adnan, re-opening with References flooding controlled applying by RSLR sinking availability, low projected sediment the the enough TRM. for with combat even like that can dike flooding, illustrates controlled the world study through the practice This polders around indigenous inside of Bangladesh. deltas sediments application of allow the zone to with dike countered coastal the be elevation thus re-open can to subsidence TRM and like SLR projected of effect The at,D . urmna,V 19) etr n ieaoyo eiet rmteGanges- the in Netherlands. the congestion the University, drainage Wageningen from mitigate on to sediments Thesis depoldering MSc Temporary implicati- of Bangladesh Management: environmental of River mineralogy delta Tidal their southwest (2013). and and L. Bangladesh Die, Texture de Basin, (1997). Bengal V. the in Subramanian, ons. system & river K., Brahmaputra-Meghna Bangladesh. D. in beels Datta, and baors, haors, of Bangladesh Management Forests, analysis. Management (2009). trend and through Environment R. coast of T. Bangladesh Chakraborty, Ministry on Environment, rise of level Department sea (CCC), of ca- Assessment Cell (2018). (2016). L. 3 the C. E. and C. Tompkins, Cell, deltas: 2 & 1.5, . mega a . . for S., https://doi.org/10.1007/s10113-018-1311-0 in deltas?. rise 1842. Hazra, vulnerable sea-level C., influences other of Hill, and D., implications human Ganges-Brahmaputra-Meghna D. the Hornby, L´az´ar, and are N., J., What A. R. Subsidence Nicholls, S., (2015). Brown, J. Ganges–Brahmaputra–Meghna. R. the 10.1016/j.scitotenv.2015.04.124 Nicholls, of floods. & 1988 se and S., 1987 the and Brown, to distribution background sediment geographical Suspended Bangladesh: mouth. Journal in (1994). phical river Floods S. (1990). Ganges-Brahmaputra W. H. the Moore, Brammer, off & ocean L., https://doi.org/10.1016/0025-3227(94)90076-0 coastal R. 41-61. the Miller, (1-2), A., in S. transport Kuehl, residual K., D. Barua, niomna Geology Environmental ihs ae ee ln h ie ece faot7mAMSL. m 7 about of reaches river the along level water highest Bibechana cec Postprint Science , 1 22.di 10.2307/635431. doi: 12-22. , , 5 o:10.1016/B978-012179460-6/50352-7. doi: 15. , 15 712 o:10.3126/bibechana.v15i0.18688. doi: 97-112. , , 1 , 30 1,e03.di 10.14340/spp.2014.12A0001. doi: e00038. (1), H´erodote 34,1118 o:10.1007/s002540050145. doi: 181-188. (3-4), e-aieLetters Geo-Marine 2,95-118. (2), , cec fteTtlEnvironment Total the of Science , 11 7 3,176-185. (3), , nentoa ora fEvrnetl Chemical, Environmental, of Journal International 21 einlevrnetlchange environmental Regional 2,6-4 o:10.1007/s003670100069 doi: 66-74. (2), 0 ls ces 9Spebr 2019). September, 29 access: (last C01 ° iei lblma eprtrsi the in temperatures mean global in rise C , esn o aeBasin Lake for Lessons aieGeology Marine 527 lmt Change Climate 6-7.doi: 362-374. , , . 18 6,1829- (6), Geogra- , 120 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. pehie,M,Gaoi,B,Hne,J,vnd a,R,Mga,A . b-laa,A,...&Hy J. Hay, & communities. and . . coasts . Islands, A., Abd-Elgawad, lying low K., A. for Magnan, implications R., and the Wal, rise of de level van characteristics Sea J., flow (2019). Hinkel, Environmental B., Glavovic, (2015). M., M. Oppenheimer, H. A. Saadat, 10.12983/ijsres-2015-p0208-0218. & doi: M., 0208-0218. T. Bangladesh. A. River, M. Gorai (NAPA). Rahman, Action H., of S. Program Moly, Adaptation National Bangladesh (2015). (2005). B. A. MoEF, Payo, (1996). & (Eds.). frame- U. . . model B. . strategies change–A Haq, J., & environmental R. J., and Nicholls, Milliman, climate S., under Szabo, Bangladesh R., coastal A. work. in Akanda, southwest H., livelihoods in Tidal Adams, Agricultural of polders D., acceptability in Clarke, Enhancing time ri- L´az´ar, N., (2019). inundation Brahmaputra reduced J. A. and Griffioen, and deposition S., Ganges sediment Dekker, Bangladesh, P., improved The by Schot, Management (1999). H., River Middelkoop, K. F., Ogawa, M. Islam, & Y., Gorai sedimentation. Yamaguchi, under and 2016-17 F., denudation 10.1002/(SICI)1099-1085(19991215)13:17 to basin S. 2014-15 Bangladesh: Begum, of in vers period R., time (BWDB). M. Board the implementation Development for Islam, for Water river Bangladesh modelling gorai (phase-ii). mathematical the project of restoration Morphological river dredging (2017). maintenance (IWM), to (BWDB). Modelling support Board Development Water Water Bangladesh of district. Satkhira Institute management and flood Jessore and under drainage basin sustainable river for study Kobadak Feasibility of (2010). Documen- (IWM). Scientific Modelling Water Module of (MT) 2012. Institute Transport Demark, Mud Environment, MODEL & FLOW Water 3 DHI MIKE tation, & Documen- 21 Scientific MIKE Module D.H.I., (HD) 2012. Hydraulics, Hydrodynamic Demark, MODEL Environment, FLOW & 3 Water MIKE DHI the & tation, in 21 mechanism MIKE Future. D.H.I., transport Earth’s Hydraulics, sediment 2300. and year distribution pa- to Flow delta. Development mitigation temperatures (2016). Ganges-Brahmaputra-Meghna and Adjusting global M. of (2018). in Rahman, systems M. rise & estuarine J. Sumaiya, C Matter, A., 2.0 & Haque, and J., C R. 1.5 Nicholls, at S., climate https://doi.org/10.1002/2017EF000732 Brown, stabilize D., and to composition I. thways species Haigh, 10.3390/f7120305. mangrove P., doi: in 305. changes Goodwin, 7, long-term Forests, Mapping Sundarbans. (2016). the C. 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(1), nentoa ora fSinicRsac nEvrnetlSciences Environmental in Research Scientific of Journal International , 75 1-2.di 10.1016/j.envsci.2017.05.020 doi: 111-120. , UdrReview). (Under < 2907::AID-HYP906 e-ee ieadcatlsbiec:cue,cneune,and consequences, causes, subsidence: coastal and rise Sea-level , 12 17 6,11-01 o:10.1039/c4em00600c. doi: 1018-1031. (6), yrlgclProcesses Hydrological nentoa ora fEvrnetlScience Environmental of Journal International > 3.0.CO;2-E. lbladPaeayChange Planetary and Global hk,Bangladesh Dhaka, , 13 1) 9722.doi: 2907-2923. (17), 1 , 50 , . 3 (1-2), Envi- (6), Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. a tvrn .F,vnTtnoe .P,&Wre,J .(08.Tetnhdao:cnrle seasonal controlled delta. dragon: Mekong tenth The Vietnamese (2018). the F. for J. plans Warner, & policy planning P., long-term J. Tatenhove, in van flooding F., M. study Staveren, case van A river: tidal In in Bangladesh. management Khuksia, Sediment 10.1051/e3sconf/20184002050. (2018). Beel K. East Kawaike, of of & area H., coastal Nakagawa, selected R., for Talchabhadel, (TRM) management river 10.1.1.298.2254. Tidal doi: (2012). 1-6. congestion. M. drainage Paramanik, mitigate & to multi-channel P., Bangladesh a M. in I. discharge river M. decreased Shampa, by caused formation plug Salt (2016). K. Y. estuary. Cho, & C., sys- D. Ganges-Gorai Shaha, the of morphology the 10.1007/1-4020-2480-0 on interventions doi: human upstream of In Impact tem. (2004). H. floodplains human-controlled M. the Sarker, in dynamics Delta. sediment Bengal drown? active to the Doomed (2017). of I. Overeem, & ‘abandoned’tide- K., the Rogers, on sedimentation Monsoon (2013). R. plain. D. 10.1016/j.ecss.2013.07.014. Mondal, delta & L., Ganges–Brahmaputra S. influenced Jr, Goodbred G., K. Rogers, o n h rnecrlsrpeettd oiae o;tege rarpeet h aito ftidal of regimes variation flow the different represents for area SSC of grey mixed variation the represent Seasonal flow; 5: rectangles Figure dominated green the tide flow, represent dominated circles average Pre-monsoon river (b) orange ranges and represent season, the Dry triangles River (a) and blue during Ganges regimes flow The flow from different Monsoon. for bifurcation levels (c) water and and the ranges tidal at Mean River 4: Figure Gorai of flow Bangladesh tide-dominated discharge of rainfall (c) monthly monthly regime, Average flow 3: mixed Figure (b) regime, flow river-dominated (a) regime for Bangladesh southwest Hydrograph of 2: regimes Figure flow different of Regions 1: Figure regime flow and seasonality regulation, Legends flow Figure the southwest considering Widespread matrix of (2017). Scenario deltaplain R. 1: Table Hale, tidal & human-modified B., the Mallick, in Tables S., waterways Sams, navigable J., and Gilligan, channels Bangladesh. C., tidal Small, of S., infilling Goodbred, discharge, wetland. of C., freshwater Effects Wilson, (2017). tidal H. restored Middelkoop, recently 10.1002/hyp.11217. & a doi: K., in 2827-2841. to Sloff, sedimentation (16), M., down on Perk, Policy, closing tide Water der From van and Bangladesh. tides. E., wind, of Deijl, the delta der in southwest van Bringing E., the Verschelling, (2017). in A. Management 10.2166/wp.2016.029. S. River doi: M. Tidal 147. Khan, via 19(1), & polders F., delta J. up Warner, opening F., M. Staveren, van h agswtrdvrin niomna ffcsadimplications and effects environmental diversion: water Ganges The cetfi reports Scientific , 20 lmnaSineo h Anthropocene the of Elementa-Science 3,2721 o:10.1080/1523908X.2017.1348287. doi: 267-281. (3), , lmnaSineo h Anthropocene the of Science Elementa 4. 6 77.di 10.1038/srep27176. doi: 27176. , 3 e fConferences of Web E3S nentoa ora fsinic&tcnlg research technology & scientific of journal International surn,CatladSefScience Shelf and Coastal Estuarine, , 13 5 7) o:10.1525/elementa.263. doi: (78). , Vl 0 .000.EPSine.doi: Sciences. EDP 02050). p. 40, (Vol. 5 6) o:10.1525/elementa.250. doi: (65). ora fevrnetlplc & policy environmental of Journal p.4-0.Srne,Dordrecht. Springer, 49-80). (pp. yrlgclProcesses Hydrological , 131 9-0.doi: 297-309. , , 1 , (5), 31 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. aaue nti eerhi rvddb W.Teatosd o aetergtt hr data. share to right the have not do authors The IWM. by darker provided is to research lighter this from in used gradient Data colour The Statement tide-dominated. scenarios. (c) to Sharing the river-dominated and Data from (b) all flow (a), (c) for of figures and efficiency gradient the regime the of trapping flow represents legends mixed Estimated the (b) 7: (d) regime, regulations. Figure flow flow river-dominated different (a) under regime for flow deposition tide-dominated sediment Seasonal 6: Figure 14 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. 15 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. 16 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. 17 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. 18 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. 19 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. 20 Posted on Authorea 7 Jan 2020 — CC BY 4.0 — https://doi.org/10.22541/au.157843099.95556612 — This a preprint and has not been peer reviewed. Data may be preliminary. 21