SEASONAL VARIABILITY IN SEDIMENT DISTRIBUTION ALONG THE SOUTHWEST COAST OF TAMIL NADU, INDIA (original) (raw)
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A study on sediments depositional mechanism at Nayakankuppam coast, Tamilnadu, India
Textural analysis carried out for the sediments of the Nayakkankuppam coast revealed that inlet part is dominated by fine sand, central part is dominated by medium sand and outlet part is dominated by coarse sand. The grain size parameters namely Mean size (MZ), standard deviation (σ1), skewness(Ski), and kurtosis (KG) of percentile values derived from the cumulative curves following Folk and Ward and the moment technique based upon grouped data are most widely used. It is observed that in Nayakkankuppam, most of the samples were fallen in the moderately well sorted to well sorted nature. Skewness measures asymmetry of frequency distribution and marks the position of mean with respect to median. The fine skewed nature of the sediments clearly exhibits sediment input from various sources of tributaries. The finely skewed nature is also implies a low velocity than normal, this skewness data indicated that the sediments are nearly symmetrical to fine skewed, the median class of the sediments dominate almost throughout their distribution. The kurtosis data indicated Mesokurtic to platykurtic. The CM pattern divulged that the sediments were transported bottom suspension and rolling as well as graded suspension. The comparison with the tractive current diagram, the berm samples fall in beach environment, the remaining samples fall in beach and tractive current environment.
Depositional environment of sediments along the Cuddalore coast of Tamilnadu India
Surficial sediments of beaches along the Cuddalore, central coast of Tamilnadu from Ponnaiyar estuarine to Thirumulaivasal were studied for their textural parameters namely Mean (Grain size) phi, Standard deviation, Skweness and Kurtosis and mineral percentages. Observed variation of energy conditions are controlled by the fluvial profile in the river channel. Textural analysis of medium sand shows the existence of comparatively high energy condition in the marine environment and low energy conditions in the fluvial zone. Linear Discriminant Function (LDF) analysis of the samples indicates a shallow marine environment origin for most of the samples and very few numbers of samples originated from fluvial environment. Heavy mineral content serves as an index for stratigraphic correlation of unfossilferrous strata. The lowest heavy mineral content indicates progradational activity and low energy wave conditions. These results show that reworked sediments, submerged during the Holocene marine transgression are being deposited on present day beaches by waves, currents and rivers in the study region.
Seasonal (post-and pre-monsoon) changes in texture and environment of deposition of beach sediments of Karnataka coast have been studied using various statistical parameters (Mean size, Standard deviation, Skewness and Kurtosis). These parameters were obtained for all the sieved sediment samples (68 for each season), using Gradistat V8.0 and G-Stat software packages. Based on the range of variability of these statistical parameters, the studied coast has been divided into four sectors. Sector I extends from Talapady to Surathkal; sector II includes beaches from Mukka to Kota. Sector III comprises Marvanthe and Nesther beaches and those lying between Murdeshwara and Devbagh fall in sector IV.Passega's CM and Tractive current diagrams were prepared to understand the energy condition of depositional currents and mode of transportation of sediment respectively. Linear Discriminant Function (LDF) plots were used to understand the environment of deposition of sediments. TheCM diagram reveals predominance of beach and tractive currentconditions along the entire coast. The Tractive current diagram indicates that deposition of sediment takes place by rolling and bottom suspension during post-monsoon, whereas by graded suspension and no rolling conditions during pre-monsoon season in sector I. In sector II, deposition of sediment takes place by bottom suspension and rolling during both the seasons. In sector III, the sediments show change in energy conditions with time where they are deposited by rolling during post-monsoon, whereas prevailing of low energy condition during pre-monsoon season as deposition of sediment takes place by bottom suspension and rolling. In sector IV, bottom and graded suspensions have been the dominant mode of deposition during both the seasons. The LDF analysis of sediment samples indicates dominance of shallow marine environment of deposition for both the seasons. The LDF plotsreveal that sector I predominantly belongs to beach shallow to beach littoral environment for both the seasons. Shallow marine agitated environment of deposition was observed for the postmonsoon season in sector II, while increase in energy conditions at this sector led tobeach shallow environment of deposition during the pre-monsoon season. Sector III shows predominance of beach littoral environment of deposition for the post-monsoon, while beach shallow environment of deposition during the pre-monsoon indicating decrease in energy conditions. Sector IV plots show little or no change for both the seasons and the samples predominantly fall in shallow marine agitated environment of deposition.
Seasonal Variation of Beach Sediment Dynamics of the Coleroon Coast, Tamil Nadu, India
International Journal of Earth Sciences and Engineering
The present study was carried out in order to study about the textural characteristics of sediments, and their seasonal changes along the coast of Coleroon. Samplings were done at different station during two seasons from monsoon 2009 to postmonsoon 2010. Granulometric studies reveals that the grain size parameters at different beach locations do not suggest a general trend of longshore variations, except on the beach close to the river mouth. The differences between the seasons were larger than those between the geomorphological units. During the monsoon the mean size was medium, sorting was worse and the distribution was more positively skewed. The major part of the sediment fall in a medium to fine grained category.
Textural Characterization of Coastal Sediments along Tamil Nadu Coast, East Coast of India
Procedia Engineering, 2015
Particle size characterizations of beach sediments along Tamil Nadu coast was carried out in the present study. The main objective of this work is to identify the textural behaviour of beach sediments and how wave energy correlates with grain size distribution.To achieve this goal tri-plot analysis was performed. Grain size characteristics such as central tendency, kurtosis and skewness were estimated using an updated version of the GRADISTAT programme and discussed in this paper. The highest sediment samples having medium sand with unimodal and bimodal characters at all along the coast. The entire coastal area was characterized as well sorted, moderately well sorted and moderately sorted sediment environments. Sediments were identified as fine skewed to coarse skewed with platykurtic, mesokurtic and leptokurtic characters. Grain characteristics varied spatially and temporally along with beach orientation, foreshore slope withwave action and skewness correlates with shoreline changes. In some coastal tract having the negative skewness along the study region, but not very significant. The study depicts that the sedimentary coastal environment were influenced by the relatively medium wave action and some places were observed high wave action. From this study, it was concluded that the beach erosion, accretion, and stability of beaches are controlled by strong hydrodynamic and hydraulic process.
Textural Analysis of Coastal Sediments along East Coast of India
Journal of the Geological Society of India, 2020
The study investigates textural characteristics of sediment at selected tourist beaches extending from Rameswaram to Paradip along east coast of India. Samples were taken from backshore and foreshore at nine selected locations to evaluate sediment grain size distribution and its seasonality. Analysis of grain size distribution carried out to identify textural characteristics (mean size, standard deviation, skewness and kurtosis) and its variability in two different seasons (southwest and northeast monsoon). Results show that sediments lying in backshore regions are mostly medium sand, while its changes are relatively invariant against seasons. The percentage of fine sand is higher during January compared to September due to prevalence of calm wave conditions. The mean grain size trend decreases at backshore region while it increases at foreshore region from south to north along the coast indicating dominance of aeolian transport. Sediments are mostly moderately sorted at backshore and moderately well sorted at foreshore region. Mostly symmetrical and mesokurtic sediments are dominated along the coast indicating sediments are well sorted at central portion of sediment distribution. The CM diagram depicts sediment source are from beach environment during both the seasons and some of them transported by tractive current in September and transporting during September is by rolling, bottom suspension and rolling; and graded suspension no rolling.
Textural characterization of coastal sediments along udupi coast, west coast of india
2016
Particle size characterizations of beach sediments along Tamil Nadu coast was carried out in the present study. The main objective of this work is to identify the textural behaviour of beach sediments and how wave energy correlates with grain size distribution.To achieve this goal tri-plot analysis was performed. Grain size characteristics such as central tendency, kurtosis and skewness were estimated using an updated version of the GRADISTAT programme and discussed in this paper. The highest sediment samples having medium sand with unimodal and bimodal characters at all along the coast. The entire coastal area was characterized as well sorted, moderately well sorted and moderately sorted sediment environments. Sediments were identified as fine skewed to coarse skewed with platykurtic, mesokurtic and leptokurtic characters. Grain characteristics varied spatially and temporally along with beach orientation, foreshore slope withwave action and skewness correlates with shoreline changes. In some coastal tract having the negative skewness along the study region, but not very significant. The study depicts that the sedimentary coastal environment were influenced by the relatively medium wave action and some places were observed high wave action. From this study, it was concluded that the beach erosion, accretion, and stability of beaches are controlled by strong hydrodynamic and hydraulic process.
Sustainable Water Resources Management
We present the results of sedimentological responses to coastal dynamics of the Arnala beach, located between Vaitarna and Ulhas rivers, Thane district, Maharashtra, India. The coast is remarkably flat and wide and in the backshore, there is a semi-consolidated raised beach. Granulometric and mineralogical investigations and CaCO 3 measurements of the sediments were carried out to understand their variations. The CaCO 3 contents in the sediments from raised beach, sub-surface and sand pits vary between < 1 and 20%. The medium-very fine sands are moderately well sorted-very well sorted, symmetrical, very platy-to meso-kurtic and mostly uni-or bi-modal. Heavy minerals (av 39 wt%) are magnetite (av 17 wt%), ilmenite (av 15 wt%) and non-magnetic (av 7 wt%) fractions. The sediments are derived from weathered Deccan Trap basalts that occur in nearby hillocks, as shore platform and along the Vaitarna River. These sediments are mainly transported and redistributed by littoral currents. In nearshore waters, annual average wave height is ~ 0.8 m and gross littoral drift is 0.132 × 10 6 m 3. Similarity in sediment parameters and mineralogy along the more than 20-km-long and 400-m-wide coast indicates prevalence of uniform oceanographic processes in a littoral cell along the coast. Significant variability in volumes of sediment accretion/ erosion is noticeable.
Sediment Texture and Geochemistry of Beaches between Redi-Vengurla, Sindhudurg, West Coast of India
Journal of Coastal Research, 2017
Textural and geochemical determinations were carried out on three beaches (Vengurla, Aravali, and Redi) of the Sindhudurg district, Maharashtra, west coast of India. Seasonal sediments from the beach were collected during 2003-04 to understand the sediment dynamics (texture, dispersal pattern, depositional environment, etc.) and geochemical characteristics. In general, a seaward grain size fining is seen along Vengurla beach (swash-backwash phenomenon), with a coarsening seaward trend along Aravali and Redi beaches (high-energy conditions). The CM pattern studies reveal traction currents as the transport mechanism. Thus, the sediments of the study area are deposited under moderate to high-energy conditions. The geochemical study shows that the percentages of V, Cr, and Zr are greater in
Textural characteristics of beach sediments along Kalpakkam, south east coast of India
2017
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.