Effect of Holocene climate and sea level changes on landform evolution and human habitation: Central Kerala, India

Abstract

Holocene climate and sea level changes have significant bearing on the geomorphic evolution of the coastal environments. A better understanding of the chronologic events of these changes is essential not only for ensuring accuracy of the climate/sea level prediction systems developed essentially from instrumental measurements but is also important for planning developmental initiatives in coastal and near shore environments. The present study is confined to the sedimentological, palynological and stable isotopic (δ13C and δ15N) evidence of palaeoclimate and sea level records in the Holocene sedimentary archives of the coastal lowlands of Periyar – Chalakudy river systems of Central Kerala, which host one of the fast developing urban – industrial centres in south India, Kochi City. The Holocene deposit in the study area is composed mainly of sand and clay dominant sediments that fall within an age range between 5390 ± 140 yrs BP and 10,110 ± 80 yrs BP. The palynological and non - pollen palynomorphs in the sediments together with the textural and geochemical attributes indicate that Holocene sedimentation took place in the area under fluctuating environmental conditions with marked changes of climate and sea level. The northern part of the study area near Pattanam revealed multiple lines of evidence of human habitation which were subsequently buried under fluvio-marine sediments in the Late Holocene.