eãxq e«¼xc (Bengal Delta)  `ywU wngvjqx b`x Mãv I eËþcyò, mwÁÃwjZ ˆmËvGZvavivq weGk¼i ˆh-ˆKvb b`x-eÅeÕ©vi Zzjbvq meGPGq ˆewk AeGÞc eGãvcmvMGi ‰Gb ˆdjGQ| ‰B `yB b`x Aci Awngvjqx b`x ˆgNbvi mnGhvGM weGk¼i meÆe†nr ˆh e«¼xcwUi m†wÓ¡ KGiGQ, ˆmwU Mãv-eËþcyò e«¼xc ev eãxq e«¼xc bvGg cwiwPZ| Mãvb`x Zvi DîicƒeÆgyLx hvòvq KGqKwU e«¼xGci m†wÓ¡ KGi cGi ˆmàGjvGK cwiZÅvM KGi eZÆgvb AeÕ©vb MÉnY KGiGQ| ˆRgm ˆiGbGji gvbwPGò ˆ`Lv hvq, eËþcyò bG`i MwZc^ wQj cƒeÆgyLx hv gqgbwmsGni KvGQ Avw` eËþcyò e«¼xc MVb KGiwQj| eZÆgvGb ‰B bG`i MwZc^wU ˆmvRv `wÞYgyLx| AekÅ cƒGeÆ ‰B `ywU b`x Avjv`v Avjv`vfvGe eGãvcmvMGi cwZZ nGZv, eZÆgvb MVGb ‰iv cwiGkGl mwÁÃwjZfvGe mvMi mãGg wgwjZ nGœQ| b`xmgƒGni ‰B e«¼xc MVb KvhÆò×g evsjvG`Gki DcK„j ˆiLvi cÉvq kZKiv 60 fvM MVGb Ae`vb ˆiGLGQ| b`xi MwZc^ I Õ©vbv¯¦wiZ wWGcvGm´ŸvGii Ici wfwî KGi mvaviYfvGe mgMÉ e«¼xcxq DcK„j ˆiLvGK cwøgvçjxq wbwÓ˜q  e«¼xc (inactive delta) ‰es cƒeÆvçjxq mwò×q ˆgNbv e«¼xcxq mgf„wgGZ (active delta) wefî× Kiv nGqGQ| cwøgvçjxq wbwÓ˜q e«¼xc  ZzjbvgƒƒjKfvGe cÉexY nGjI ˆgNbv e«¼xcxq mgf„wg f„Zvwî½KfvGe Lye bexb| cÉK‡ZcGÞ MovB-gaygwZ b`xi cwøGg AewÕ©Z AçjGK cwøg wbwÓ˜q e«¼xc I cƒGeÆ AewÕ©Z AskGK cƒeÆ mwò×q e«¼xc aiv nq| cwøgvçjxq wbwÓ˜q e«¼xcGK mvaviYfvGe wZbwU fvGM fvM Kiv hvq, h^v- g†Z e«¼xc (moribund delta), cwiYZ e«¼xc (mature delta) ‰es ˆRvqvifvUv mg†«¬ mwò×q e«¼xc (tidally active delta/saline-tidal delta)|

eãxq e«¼xc eãxq AeevwnKvi ‰K weivU Açj RyGo iGqGQ, hv mgMÉ evsjvG`Gki cÉvq 35%| cwøGg fviZxq wkΣ, DîGi eGi±`Êf„wgi `wÞY cÉv¯¦ I cƒGeÆ wZcvivc†Ó¤ ‰i mxgvbv| e«¼xcwUi gƒj weKvGki gvòv `wÞY w`GK eGãvcmvMGi AeÅvnZ AvGQ|

evsjvG`Gk cwøg wbwÓ˜q e«¼xc (21°15´ I 24°40´ Dîi AÞvsk ˆ^GK  88°0´ I 90°0´ cƒeÆ `ËvwNgvsk) cÉvq 31,500 eMÆ wKwg ‰jvKvRyGo weivRgvb| mvaviYfvGe fviGZi gywkÆ`vev` (÷ay fvMxi^xi cƒeÆ w`GKi Ask), b`xqv I 24 ciMbv ‰es evsjvG`Gki ˆgGnicyi, KzwÓ¡qv, PzqvWvãv, wSbvB`n, gvàiv, hGkvi, bovBj, Lyjbv, mvZÞxiv I evGMinvU ˆRjv ‰i A¯¦MÆZ| cƒeÆvçjxq mwò×q e«¼xc 23°50´ Dîi AÞvsk ˆ^GK 21°55´ Dîi AÞvsk chƯ¦ ‰es 89°10´ cƒeÆ `ËvwNgvsk ˆ^GK 90°50´ cƒeÆ `ËvwNgvsGki gGaÅ AewÕ©Z ‰es ‰i AvIZvaxb ‰jvKvi cwigvY cÉvq 15,000 eMÆ wKwg| Mãv-eËþcyò e«¼xGci ‰B Ask Dîi-`wÞY gyGL cÉvq 300 wKwg jÁ¼v ‰es e«¼xcwUi Ea»Æ I gaÅ gyL h^vò×Gg cÉvq 100 wKwg I 130 wKwg PIov| cƒeÆvçjxq mwò×q Mãv-eËþcyò e«¼xGc evsjvG`Gki ivRevox, dwi`cyi, kwiqZcyi, gv`vixcyi, jßxcyi, ˆMvcvjMé, wcGivRcyi, ewikvj, SvjKvwV, cUzqvLvjx, eiàbv I ˆfvjv ˆRjv A¯¦fÆyî×|

Mãv-eËþcyò e«¼xc evsjvG`Gki AbÅZg f„-cÉvK‡wZK wefvM| ‰jvKvwU cÉavYZ ‰KwU mgf„wg hvi DœPZvi gvòv DîGi 15 wgUvi ˆ^GK `wÞGY cÉvq ‰K wgUvi| e«¼xcwUi c†Ó¤G`Gki bwZgvòv cÉwZ wKGjvwgUvGi cÉvq 0.016 wgUvi| e«¼xGci Mo DœPZv Lyjbv, ewikvj, dwi`cyGii `wÞYvçj I ˆbvqvLvjx ˆRjvi cƒeÆvçGj 2 wgUvGiiI Kg| e«¼xcwUi `wÞYvçGj ‰ DœPZv AviI Kg, gvò KGqK ˆmw´ŸwgUvi| evsjvG`Gk e«¼xcxq gvwUi DœP DeÆiZvi KviGY K‡wl KvhÆò×Ggi cÉvavbÅ AçjwUGK Nb emwZcƒYÆ KGi ZzGjGQ| AwaKvsk ˆjvGKi RxweKv Rwg Pvl, gvQ aiv, ˆbŒ-cwienY, mvaviY mÁ·G`i m«¼Åenvi (ˆhgb my±`ieGbi Mivb ebf„wg) I AbÅvbÅ A^Æ‹bwZK KvhÆò×Ggi wbwiGL e«¼xGci cwiGekMZ AeÕ©vi Ici wbfÆi KGi| ‰B mye†nr I m`v weewZÆZ e«¼xGc AeÅvnZ f„wg cwie†w«¬ I f„wgÞq evsjvG`Gki RbemwZi aib I mvgvwRK-mvsÕ•‡wZK webÅvmGK cÉfvweZ KiGQ|

e«¼xGci weeZÆb  Avw` wò×GUwmqvm hyGM MG´£vqvbvjÅvG´£i Lí-weLí nIqvi ci ˆ^GK weMZ 12 ˆKvwU 50 jÞ eQi aGi Mãv-eËþcyò e«¼xc AçGji MVb cÉwò×qv AeÅvnZ AvGQ| e«¼xc KgGµÏÝwUi weKvGki BwZnvm MG´£vqvbvjÅvG´£i wefvRb, fviZxq ˆµÏGUi wePjb, fviZxq ˆµÏGUi mGã evgÆv I BDGiwkq ˆµÏGUi msNlÆ, wekvj ceÆZGkÉYx wngvjGqi m†wÓ¡, Mãv-eËþcyò b`xcÉYvjxi weKvk, wewf®² mgGq mgy`Ëc†GÓ¤i cwieZÆb ‰es ˆKvwU ˆKvwU eQi aGi f„-MvVwbK wò×qvKGgÆi mGã IZGcÉvZ nGq AvGQ|

e«¼xcxq KgGµÏÝwUi weKvk fviZxq ˆµÏGUi wbwÓ˜q Wvb cÉvG¯¦ ÷i‚ nq hLb AeGÞGci nvi Lye g¯©i wQj| fviZxq ˆµÏGUi DîigyLx mçvi I BDGiwkq ˆµÏGUi mGã ‰i msNGlÆi KviGY e«¼xcxq KgGµÏÝwUGZ wecyj AeGÞc ÕZ„cxK‡Z nGq Zv Avw` e«¼xc (proto-delta), cwieZÆbgƒjK e«¼xc (transitional delta) I AvaywbK e«¼xc (modern delta) ‰B wZb Õ¦Gi weewZÆZ nGqGQ| e«¼xc MGo ˆZvjv  cÉwò×qv ˆmGbvGhvwqK hyGMi Uviwkqvwi I ˆKvqvUvibvwi AvgGj LyeB mwò×q wQj|

Avw` e«¼xc (12 ˆKvwU 60 jÞ eQi ˆ^GK 4 ˆKvwU 95 jÞ eQi AvGM) KvGeÆvGbU-KÑvmwUK msc†î×Zvi PviwU ài‚Z½cƒYÆ Õ¦iò×g hv cÉv^wgK chÆvGq DœP AÞvsk wbqw¯¨Z mvgyw`ËK cwiGeGk ‰es cieZÆxGZ wbÁ² AÞvskxq Aeva mvgyw`ËK wbiÞxq cwiGeGk AeGÞwcZ nGqwQj| PviwU Õ¦iò×Ggi mGã ˆevjcyi Õ¦imgwÓ¡, NvUvj Õ¦imgwÓ¡, RvjvsMx Õ¦imgwÓ¡ I wmGjU Pzbvcv^i Õ¦imgwÓ¡ ciÕ·i mÁ·KÆhyî×| 

cwieZÆbgƒjK e«¼xc  (4 ˆKvwU 95 jÞ eQi ˆ^GK 1 ˆKvwU 50 jÞ eQi AvGM) fviZxq ˆµÏU I BDGiwkqvb ˆµÏGUi gGaÅ msNlÆ ‰es cieZÆxGZ e†nîi wngvjGqi DïvGbi dGj m†Ó¡ bvUKxq cwieZÆbmgƒn cwieZÆbgƒjK e«¼xcxq hyM AwZò×g KGiGQ| KÑvmwUK ev weP„wYÆZ AeGÞcmgƒn nqZev ˆKvwcwj Õ¦imgwÓ¡i mgmvgwqK wQj ‰es ˆNvjvGmËvZ (turbidity current) AwZwiî× AeGÞGci Õ§cGK MfxiZi cvwbGZ ˆUGb wbGq hvIqvq eãxq Dce«¼xc (Bengal fan) ‰B mgGq MwVZ nGZ ÷i‚ KGi|

AvaywbK e«¼xc  cÉvq 1 ˆKvwU 50 jÞ eQi cƒeÆ ˆ^GK eZÆgvb AvKvi aviY KGi| ˆm mgq c†w^exeÅvcx mgy`Ëc†Ó¤ ˆbGg hvIqvi KviGY cƒGeÆKvi AeGÞc Õ¦iò×gmgƒn DGÍÏLGhvMÅ cwigvGY ÞqcÉvµ¦ nq| AGcÞvK‡Z mywÕ©Z ˆRvqvifvUv wbqw¯¨Z cwiGeGk e«¼xcwUi weKvk AvRI AeÅvnZ AvGQ| Mãvb`xi cÉfve AeGÞc eÅeÕ©vGK cÉfvweZ KiGZ ÷i‚ KGi| be-f„MvVwbK wò×qvKgÆ (neotectonic activity) ‰es ˆKvqvUvibvwi chÆvqfzî× mgy`Ëc†GÓ¤i nËvme†w«¬ eãxq AeevwnKvi e«¼xcxq Pvc (arc) MVGb eÅvcKfvGe wbq¯¨GKi f„wgKv cvjb KiGQ| we`Ågvb b`xmgƒn KZ‡ÆK e«¼xc MVb cÉwò×qv ˆKvqvUvibvix chÆvq RyGo AeÅvnZ ^vGK hv ZUGiLvGK cƒeÆ I `wÞYcƒeÆ AwfgyGL weÕ¦†Z KGi| ‰B AçGji AeÅvnZ DïvGbi KviGY cÉwZwU bZzb Õ¦i cƒeÆeZÆx Õ¦Gii PvBGZ AviI ˆewk mgyG`Ëi w`GK AeGÞwcZ nq|

DœP mgy`Ëc†Ó¤ wewkÓ¡ cÉexY µÏvBmGUvwmb hyM, AeevwnKvi Afů¦Gii PvicvGk Þz`Ë Þz`Ë e«¼xGci ‰KwU ejq «¼viv ŠewkÓ¡ÅgwíZ wQj| mgy`Ëc†Ó¤ cÉwZevi ˆbGg hvIqvi mgq AmsnZ e«¼xcxq AeGÞcmgƒn MfxifvGe eÅeGœQG`i wkKvi nGqwQj, wngchÆvGq (glacial stage) mgy`Ëc†Ó¤ mÁcÉmvwiZ nq ‰es b`xmgƒn AMÉgyLxb wKsev DcZÅKvGQ`b (valley cutting) chÆvGq wQj| eãxq e«¼xcwU ˆhGnZz ˆRvqvifvUv cÉfvweZ I mGã mGã b`x wbqw¯¨Z, AeGÞcmgƒn ZvB mvgyw`ËK Ziã I ˆmËvGZi UvGb QwoGq wQwUGq bv wMGq ˆewkUvB mgy`Ë ZjG`Gk w^wZGq hvq| dGj ZjG`kwU ˆRGM IGV| cieZÆx A¯¦twng hyGM, DwïZ mgy`Ëc†GÓ¤i KviGY, b`xmgƒn ÞqgƒjK ev DcZÅKv fivU chÆvGq wQj| ‰ mgGq b`x cÉwò×qv mvgyw`ËK cÉwò×qvi «¼viv AGavMvgx wQj| b`xgyGL ZvB AwaKZi AeGÞc Rgv cGo| Dfq ˆÞGòB e«¼xc Mov cÉwò×qv cÉZÅÞ ev cGivÞfvGe ‰wMGq hvq| ‰wU AvR myÕ·Ó¡ ˆh ˆgNbv e«¼xcxq mgf„wgi DœP MwZkxj cÉK‡wZ e«¼xc Mov cÉwò×qvi `ywU kwî×kvjx wecixZ Dcv`vb, b`xR I mvgyw`ËK cÉwò×qvi wg^wÕ˜qvi (interaction) dj| b`xR  cÉwò×qvmgƒn nGœQ cvwb I AeGÞGci eÅvcK ˆgŒmywg cÉevn, Avi cÉavb mvgyw`ËK cÉwò×qvwU nGœQ cÞKvjxb wf®²Zvmn ˆRvqvifvUvi cÉfve| m±«¼xc I msj™² AçjmgƒGni f„-cÉvK‡wZK cwieZÆGbi gƒj KviY cÉej mvgyw`ËK ˆmËvZ nGjI ˆfvjvi ˆÞGò ‰KB cwieZÆGbi gƒGj cÉavbZ b`xi ˆmËvZ| ZvB ˆfvjvq fvOb AwZgvòvq FZzwfwîK| nvwZqv «¼xc I msj™² AçjmgƒGn mvgyw`ËK I b`x Dfq ˆmËvGZi cÉfve mwò×q ^vKGjI wKQy ‰jvKvq, ˆhgb- DwoiPGii f„-cÉvK‡wZK cwieZÆb mgƒn ˆRvqvGii MwZkxjZvi Ici wbfÆikxj, hv nvwZqv I m±«¼xc PÅvGbGji gaÅ w`Gq AvMZ `ywU ˆmËvGZi gGaÅKvi weÕ¦vi I chÆvqMZ cv^ÆGKÅi «¼viv wbqw¯¨Z| cwøgeGãi PviwU e«¼xcxq Pvc evsjvG`Gki wZbwU e«¼xcxq PvGci mgvb| ‰àGjv nGœQ mvÁcÉwZK e«¼xcxq mgf„wg, bexb e«¼xcxq mgf„wg, cÉvPxb e«¼xcxq mgf„wg ‰es cwøgeGãi jÅvGUivBU DœPf„wg| evsjvG`Gk ‰G`i mgv^ÆK PvcàGjv nGœQ my±`ieb (mvÁcÉwZK Mãv-eËþcyò e«¼xc), Pvw±`bv e«¼xcxq mgf„wg (Avw` Mãv-eËþcyò-ˆgNbv e«¼xc) I eGi±`Ê-gaycyi Mo| jÅvGUivBU DœPf„wgi mgZ„jÅ ˆKvb Pvc evsjvG`Gk ˆbB|

[wmdvZzj KvG`i ˆPŒayix I ˆgvt Kvgi‚j nvmvb]