Context and Background of the Subarnarekha Delta Plain

Abstract

Subarnarekha delta plain is situated at the western limit of ‘Kanthi coastal plain’. This area includes an unconsolidated coastal sector of “strained plain” of Subarnarekha delta where cuspate arrangement of chenier ridges is significant feature. The entire chenier delta plain was formed by combination of marine and fluvial agencies. The chenier plain of this vicinity has prograded sea ward since the end of the Holocene transgression with the production of substantial wedge and predominantly fine-grained sediments and abandoned supply of Subarnarekha sand into the coast through major floods. Strong tidal currents of the flood tide phase usually cut across the long shore currents which continuously arrest sediments around the estuary as a result the chenier plain formation is active in the deltaic shore line of Subarnarekha river. Chenier ridges are produced between mud banks particularly during the periods of erosional winnowing. The present studied coast extends from Rasalpur to Udaipur. The study area covers an area of about 142,519.76 hector Stretching between 21° 20′ 25ʺN. 86° 52′ 45ʺE and 22° 07′ 55ʺN 87° 31′ 37″E. This area is geomorphologically productive, reach in habitat diversity and environmentally hazards prone under the events of tropical cyclones , tidal waves, climate change and sea level rise. As a result of increasing coastal hazards mainly tropical cyclone and other allied coastal hazards, oceanic processes like transgression and regression and also due to affecting on physical aspects of the environment by different types of human activities (deforestation, unscientific agricultural practices, excavetory works) shore line becomes shifted here much more frequently. Being a deltaic low lying coastal stretch this area is monotonously flat alluvium surface of ground level varying between 2.5 and 3.5 m. above MSL. The study area is mainly covered by the Holocene alluviums along with the recent Subarnarekha river’s deposition, which has a natural gradient to the east and south east direction with a high water holding capacity of brackish water environment. The monsoonal phase is much more significant in this area. There is no such forest cover except some brackish environment floral species.