Fate of Palynofacies (sedimentary organic matter) in suburban and urban
flood plains of Gomati River, Lucknow, India
Abstract
Hydromorphodynamic interactions with vegetation are a part of fluvial
biomorphodynamics in actively meandering rivers. Using palynofacies and
grain size from sub-urban to urban reaches across the river valley, we
examine the spatial patterns of organic matter behaviour in a 38 km
reach of the river Gomati in Lucknow district, Uttar Pradesh, India, in
an effort to understand how they responds to the alteration,
preservation, and degradation after getting transported and deposited in
sediment. To this we analyzed thirteen surface sediment samples of the
Gomati River flood plain for palynofacies and grain size to ascertain
its fate in this stretch which essentially is a big picture for past
settlements. The shifts in the proportions of palynofacies associations
viz. phytoclasts, palynomorphs, and amorphous organic matter (AOM) along
with grain size aims to visualize the depositional process. The CONISS
clusters analysis revealed four zones reflecting high degradation and
alteration of palynofacies in the urban regime compared to the sub-urban
reaches where the low interference with natural settings illustrate low
deterioration of palynofacies. The relationship between grain size and
palynofacies was obtained using Principal Component Analysis (PCA) to
emphasize their correlation with palynofacies in this meandering fluvial
system of Gomati River. In the flood plains deposits, the behaviours of
palynofacies, allow for the distinction of the regional aspect of
fluvial disposition. The study offers a comparison between urban and
sub-urban settlement premises of today’s communities and contributes to
our understanding of the growth, dispersal, and decline of earlier human
settlements.