IAPRS & SIS, Vol.34, Part 7, "Resource and Environmental Monitoring", Hyderabad, India.2002 
marine erosion confined to North Kanara district. The depositional 
features such as offshore bar, spit, double spit, beach, estuaries and 
tidal flats are confined to South Kanara district. The study of 
erosional and depositional features infers the nature of coastline 
under submergence versus emergence. The emergent shoreline has a 
remarkable straight alignment, dominance of offshore bar driven to 
mainland and gentle offshore profile. The submergent shoreline is 
under submergence versus emergence. The emergent shoreline has a 
remarkable straight alignment, dominance of offshore bar driven to 
mainland and gentle offshore profile. The submergent shoreline is 
characterised by crenulated coastline, abundance of estuaries 
representing old river mouth drowned by rising sea-level fluctuation 
and locally called backwater. The broad characteristics of identified 
ten coastal features are summarised as follows 
Coastal Plain 
It is extended along 320 km in length over the entire coast. It has 
average width of 15 km and average elevation of 0— 15 m MSL. It 
has major transportation route like NH 17, Konkan Railway line 
with prominent towns like Mangalore, Udipi, Kumuta, Honavar, 
Coondapur, Mavalli, Bhaktl, Marvante and Karwar. (Nazarath et 
al., 2002). 
Island 
There are several tiny islands within the reach of coastline upto 72 
km. These islands are composed of shale, pebble and concrete grit. 
Some ofthe islands have elevation upto 70 m with marshy & thick 
vegetation. It infers submergence nature of the coast. The 
prominent Islands are Saint Mary near Karwar and Pigeon Island 
near Bhaktl. These are marked as permanent feature on toposheet 
(Misra, 1973; Ahmad, 1972). 
Marine Erosion 
It is common during four months of rainy season i.e. from June 
— September. It has been observed at certain areas around Karwar, 
Coondapur, Udipi and Mangalore on account of prevailing 
destructive wave action. The wave reaches upto height of 6 m 
during monsoon period and are even less than a meter during rest 
period. Ganguli village has severe marine erosion around 
Coondapur. It is well documented over aerial photograph of April 
1955 (Figure. 1) as well as its activity has been cross checked in 
field during beach profiling (Malick et al., 1990). Similarly Bengre 
locality has prolonged marine erosion around Mangalore. It is well 
documented over toposheet of 1910 & 1967, Landsat imagery of 
1972 and Aerial photograph of 1979 as illustrated in Figure 2 (a, b & 
c). The comparison of these temporal aerospace data indicates 
gradual shifting of spit towards seaside. It is due to littoral drift as 
long term activity, which has been well documented as sediment 
dispersion plume over Landsat] MSS data. Sea wall has been 
constructed at Vllal, Bengre to check the marine erosion along both 
ends of Nethravati-Gurupur estuaries (Bhatt, 1995). 
Estuaries 
These are parallel to coastline with sharp bend river mouth. 
Netravati — Gurpur estuary is a prominent feature near Mangalore 
and observed through Aerial photograph, Landsat MSS and IRS 
data. The estuary mouth has dynamic morphological change due to 
continuous tidal impact and influence of river discharge. The 
450 
estuaries are navigable for distance of 20 - 25 km through four 
Tonne capacity boat. 
Tidal Flat 
These are stabilised landform along estuaries and associated with 
Phantom drainage. It is well observed over Landsat MSS data. It is 
the storehouse for paddy field, sugarcane cultivation, coconut trees 
besides marshy to mangrove (Gupta et al, 1985). 
Offshore Bar 
It is a depositional feature having highly temporal in nature. It is 
developed normally along backwater and composed of 
inhomogeneous grain size of sand. It is well documented over all 
kinds of aerospace data with classical example near Netravati 
Gurpur estuary (Gupta et al, 1978). 
Spit and Double Spit 
It is a kind of offshore bar with curve at its end. These are 
developed along depositional activity under rapid morpho-dynamic 
changes due to the influence of coastal dynamic processes. These 
are identified over Aerial Photograph, Bhaskara II, Landsat MSS 
and IRS data. 
Beach Deposit 
The fine beaches with dunes are observed through different kinds of 
aerospace data at Coondapur, Marvante in between Bhaktl and 
Udipi. 
Wavecut Cliff 
It is a marine erosion feature and is well documented near Karwar. 
It is associated with several spit and offshore bar in Northern and 
Southern sites. The culminated nature of coastline indicates the 
submergence nature of coast and well documented over Landsat! 
MSS data. , 
Sediment Dispersion 
It is governed by primary force as river discharge and secondary 
force like wind current its magnitude and direction. It is highly 
temporal in nature and associated with marine fishery resources. 
The fishing activity is intensified during September to March for 
catching species like Pearl fish, Millet, Cockpit, Prawn and Cattle 
fish of export quality. Karnataka coast is very rich for marine fish 
on account of torrential river discharge into sea - a lot of vegetable 
food for them. 
The sediment dispersion pattern mostly belonging to suspend in 
nature is influenced by orientation of coastline, interaction of wave 
front and wind - current direction for short period. The wind 
direction is NW-SSE during November — January while current 
direction is from South. In February reversal takes place in 
clockwise, which lead the wind direction during February - May in 
SW-NE. The wind direction is NW-SE during June to August. The 
current direction takes place from N-S during February-October is 
strongest in May, June and July. The variation in wind-current 
direction governs the sediment dispersion during September and 
December (1972) as per Landsat is illustrated in Figure 3 (a & b). It 
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