Beach Sediment Analysis

CHAPTER 5

VARIATION IN TEXTURAL CHARACTERISTICS OF BEACH AND NEARSHORE SEDIMENTS Introduction

The alternate changes of sediment in the beach territory play a great role in determining the morphological response in coastal regions. Changes that involve the movement of particles from one place to another is the key factor in altering the morphology of the beach; include the loss and gain of sediment and influence the formation of beach surface. Therefore, studies related to sedimentological characters become more crucial nowadays as the nature of the beach surroundings are sensitive and delicate which often deals with dynamic equilibrium (Carranza-Edwards et al., 1998).

The textural characteristics of sediment of recent coast reflect the sedimentary

According to categorization by Wentworth (1922), mean size of sediment at the study area predominantly classified as very coarse sand, coarse sand, medium sand and fine sand type. Most of these sediments show angular in shapes. In overall, Table 5.2 shows the mean size of the sediments range between -0.60 φ – 2.85 φ.

Station 1 (TC) – The beach sediments at this site were mostly dominated of coarse sand that ranges from 0.14φ to 2.07φ and the second largest portion was very coarse sand ranged between -0.69φ and -0.08φ (Table 5.2). The highest and lowest values were equally foundin the swash zone during April 2012 (2.07φ) and June 2012 (-0.69φ). It was noted that the rocky surrounding at this beach, which acted as the geological control of the site, influenced the sedimentary supply for the surrounding area. Sediment was relatively coarser during the months of the northeast monsoon, with the grain-size value decreased through the month of October, December and January (Figure

The fine sand content ranged from 2.03φ to 2.78φ while the medium sand ranged from 1.07φ to 1.98φ (Table 5.2). Medium sand grains were dominated mostly at areas of high-tide and mid-tide, while the fine sand occupied at lower tidal regions which is low-tide and swash zone. However, during the northeast monsoon in January 2013 and February 2013, a gradual decline of mean size values obtained thus increase the sediment size at the beach area.

Station 5 (SUN) – The station dominated by both medium and fine sand that ranged from 1.16φ to 2.00φ and from 2.06φ to 2.74φ respectively (Table 5.2). It can be noted that fine sand grains found to predominate at the early period of survey especially during February till April 2012. Meanwhile, medium sand was obtained frequently towards the end of survey period i.e. December 2012 to February 2013. However, in the middle of the study period, both medium and fine sand were scattered randomly at all tidal