Coastal processes

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Slide 24

For many years this alongshore energy flux per unit length of beach,Pl was correlated empirically with the volume sand moved by the waves.

Amount material moved,

Q= CPnl B

Where C is a dimensional constant of proportionality. The power n has been found to be close to unity.

equation A as being dimensionally incorrect. Then corrected the equation as

Q=KPl/[(ρ s- ρ)g(1-p)]

Slide 25

Where -p is the porosity of the sediment, which is typically about .3 to .4. the porosity is introduced to convert sand weight to sad volume, taking into account the voids that occur with in the sand.

K-is the dimensionless parameter, its value ranging from 0.2 to 2.

Slide 26

Longshore Sediment transport rate at different locations in India

Longshore sediment transport rate (LSTR) reported for different locations along the Indian coast shows local reversals in the transport direction in a number of locations along the west coast.

It was found that the annual gross sediment transport rate was high (»1 * 106m3) along the coast of south Orissa and south Kerala.

Slide 27

Sediment transport rate at different locations in India

Location Net transport Gross transport

(m3/yr) (m3/yr)

West coast of India

Kalbadevi 118,580 South 147,621

Ambolgarh 189,594 South 299,997

Vengurla 53,040 South 120,141

Calangute 90,000 South 120,000

Colva 160,000 North 160,000

Arge 69,350 North 200,773

Gangavali 142,018 South 177,239

Kasarkod 40,186 North 77,502

Maravanthe 25,372 North 29,836

Slide 28

Kasargod 736,772 South 958,478

Kannur 19,434 South 561,576

Kozhikode 114,665 South 256,697

Nattika 192,818 North 660,276

Andhakaranazhi 202,096 South 599,484

Alleppey 16,929 North 62,519

Kollam 383,784 South 805,296

Thiruvananthapuram 99,159 North 1231,153

Kolachel 302,400 West 946,500

Slide 29

East coast of India

Ovari 1,500 South 251,300

Tiruchendur 64,100 North 87,500

Kannirajapuram 117,447 North 145,979

Naripayur 36,600 South 122,500

Muthupettai 5,200 South 8,900

Poompuhar 146,000 North 478,800

Pondichery 134,400 North 237,000

Periyakalapet 486,900 North 657,600

Tikkavanipalem 177,000 North 405,000

Gopalpur 830,046 North 949,520

Prayagi 887,528 North 997,594

Puri 735,436 North 926,637

Slide 30

Onshore-offshore transport