Textural characteristics of beach sediments along Kalpakkam, south east coast of India

Abstract

Samples collected from foreshore region showed more variations in grain size as compared to mid-shore region samples. Median values varied from -0.08ø to 2.19 ø with an average of 1.04 ø (Std ± 0.65 ø). Mean value showed that samples were fine to coarse sand, whereas, only 1.8% of total samples were found as very coarse sand. During southwest monsoon the average mean size of the beach sediment was 0.98 ø, which is coarse sand in contrast to the medium sand observed during other seasons. Present study showed that, 81.7% of the samples were unimodal and 17.8% samples were bimodal. Sediment samples were very well sorted (0.18 ø) to poorly sorted (1.18 ø) and sorting characteristics decreased with increased wave energy. Skewness value indicated that 41% & 11% of the samples were positively skewed and negative skewed respectively, whereas, rest of the samples were symmetrical. All the beaches were dominated by mesokurtic sediment. Dominance of positively skewed sediment in the study area indicated the prevalence of low wave activity and longshore current. Presence of relatively high fraction of mesokurtic sediment indicated that the beaches along Kalpakkam by and large have uniform energy environment.