Spatio temporal Variations of Sediment and Water Characteristics of a Tropical Estuarine System Southwest Coast of India

Abstract

Estuaries are complex ecological systems that mark the transition between newlinefresh water and sea. Among the various sedimentary environments, estuaries newlineand nearshore areas are important as they act as sinks for sediments and other newlinedisposals while the rivers are the major sources of sediments which are newlinetransported through estuaries into the oceans. The fresh water input into the newlineestuaries are indispensable as they are the carriers of carbon, nitrogen, oxygen newlineand other substances into the downstream ecosystems, required for supporting a newlinerich variety of life. The characteristic circulation patterns produced by the mingling newlineof fresh water brought by the river and the salt water from the sea, makes newlineestuaries effective sediment traps. From time to time the estuaries perform as newlinefilters to the riverine input and transform the behaviour of the influx materials. newlineComparatively the rate of deposition in estuaries are naturally high, but the man s newlineactivities both within the estuarine zone and throughout its drainage basin can newlinealso increase the sediment yield and rate of filling. This can alter the natural newlinesedimentation pattern and can shorten the geological lifetime of estuaries. It is newlinenecessary to understand these fragile environments, in relation to their physical newlineand chemical processes to maintain, manage and check their pollution hazards. newlineSeveral studies related to texture and geochemical data on sediments are newlineincreasing, as they are the reliable tool to understand its surface processes, newlinedepositional history, degree of source area weathering, provenance, tectonic newlinesetting, paleoenvironment etc. Present study comprises of three ecosystems newlinestretching from source to sink, that includes Vamanapuram River which originates newlinefrom the Western Ghats, Akathumuri-Anchuthengu-Kadinamkulam Estuary and newlineadjoining nearshore areas in the Thiruvananthapuram district, Kerala. This work newlinehighlights the textural, geochemical and hydrochemical variations in the sediment newlineand water with special emphasis on the land use land