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TRINCOMALEE BAY SPECIAL MANAGEMENT AREA Page | 24
together with the proposed construction of bridges at existing ferry crossings, will open up
rapid access to the coastal area south of Trincomalee and enhance opportunities for
development of this area.
3. Climate
97. The entire eastern coast is located within the dry zone of Sri Lanka, which has a hot
and humid tropical climate. The mean annual temperature is 28.5 o C, although typically this
ranges from 18 o C on cooler nights during the rainy season, to 39 o C during the day in the dry
months. Eastern Province receives rainfall of between 1000 to 2000 mm per annum,
primarily, about 60%, from the northeast monsoon during October to February.
98. Trincomalee District has a longer dry spell than the three months dry spell found in
the other two Districts of the Eastern Province. Average annual rainfall during the period
1995-2000 was 1,469 mm most of which fell in the north east monsoon. This suggests a
decline in annual rainfall from earlier years, since the 1951 to 1980 average was 1,615 mm.
99. Sri Lanka’s east coast is frequently hit by storms and cyclones, especially during the
northeast monsoon, and these can cause considerable damage to property and threaten
lives. Trincomalee bay is also frequently hit by minor storms in the rainy season. Winds are
generally moderate, ranging from 7-15 km per hour with the evening winds being stronger.
100. According to the agro-climatic zone of Sri Lanka, the area covered in the Trincomalee
bay SAM area belongs to the DL 1 , DL 2 and DL 4 agro-climatic zone. Accordingly, DSDs of
Town & Gravets, Kuchchaveli, Thampalagamam and half of Kinniya Division fall within the
DL 1, which is dry zone low country-1. Half of Kinniya DS division and part of the Muthur
Division fall within the DL 2, which is dry zone low country-2. Sampoor section of Muthur DS
Division belongs to the DL 4, which is dry zone low country-4, which is equivalent to an arid
zone. The rainfall, major soil types and land use features vary according to these agroclimatic
zones.
4. Geology & soils
101. The geological formations to the north and northwest of Trincomalee bay consist of
charnockites and quartzites, along with more recent alluvium. The hilly areas around the
harbour mainly consist of rocky areas with charnockites and quartzites. Bands and lenses of
base charnockite of variable thickness are found in the Inner Harbour area and form the
Elephant Ostenburg, Clappenburg, Engineer and Cod ridges, China and Orr’s Hill, along with
the southern ends of Great Sober Island and most of Small Sober Island. Dolerite and
pyroxenite dykes are present in outcrops at Had Cove, Sober Island, Deadman’s Cove and
near the road at China Bay airport. Most of the acid charnockite is found between Elephant
and Ostenburg ridges, Diamond Hill, Nicholson’s Bay, Malay Cove, Deadman’s Cove and
Sweat Bay. Garnet-biotite gneiss bands are found at Snug Cove, Clappenburg bay, off Cod
ridge and north of Engineer ridge. The areas south, southwest and southeast of Trincomalee
bay are characterized by recent alluvium, while Norway Point is also characterized by the
presence of garnet-biotic gneiss.
102. Soils are mostly sandy regosols and recent beach and dune sands, with areas of
riverine alluvial soils. Further in the interior there are reddish-brown earths and their
derivatives. Reddish-brown earths occur to the west and southwest of the bay, whilst sandy
regosols and alluvial soils are characteristic around the rest of the bay. Low humic gley soils
dominate the paddy lands in the adjoining areas.