VARIATIONS IN TOTAL ORGANIC MATTER IN BED SEDIMENTS OF TAWA RIVER

Abstract

The Tawa River is the longest tributary of the Narmada River of central India. It originates from the Satpura range and joins Narmada River at Hoshangabad district. In order to quantify the seasonal and spatial variations in total organic matter in the bed sediments of Tawa river, a total of 22 samples were collected in three different periods, post-monsoon (October, 2010), monsoon (August, 2011) and pre-monsoon (January, 2012) . It is observed that there are wide temporal and spatial variations in organic matter. The variations range from 1.63% in monsoon to 0.32% in post monsoon period where as in pre-monsoon period it is 0.608%. The annual water flow data was used for inferring the variations of organic matter. The reasons for the variations in organic matter in sediments may be related' to water flow, sediment concentrations and bed sediment deposition, transport of organic matter and soil formation. The dense forest catchment provides a significant leaf litter to the bed sediments of the river. Basin geology, land use pattern and soil characteristics also influencing the organic matter content in the bed sediments. Due to presence of the Tawa Dam and reservoir in the upstream of the river, it has been observed there are significant variations of organic matter before and after the reservoir