Managing Arid Areas and Sand Dunes in Sri Lanka - Combating Desertification in Asia, Africa and the Middle East - page 314

In Sri Lanka, there are two dry zones found in south-east area of Hambanthota
District and north-West area of Mannarama and Puttalama Districts. Both dry zones
are situated near the coastal zone. The altitude of the area is 0-100 m and the wet
season of 4-5 month peaks in September-November (the north-east monsoon). The
temperature is nearly 35 ı C. The cause of aridity in this areas can identified as

• Low annual rainfall less than 1,200 mm/year.

• Deforestation

• Salinization

• Overgrazing.

• Over cultivation

• “Chena type” shifting cultivation and illicit human activities

• In the arid zone; thorn forests and drought-resistant shrubs are found.

The characteristics of those forests are: Short (about 2-5 m high) thorny bushes
are present and drought resistant through a number of adaptations relating to
morphology, physiology and crop architecture.
The prominent species of this area are Zizyphus oenoplia - Heen eraminia
(sinhala), Carissa carandas - Maha karanda (sinhala), Bauhinia racemosa - Maila
(sinhala), Dichrostachys cinerea - Andara (sinhala), Opuntia dillenii - Pathok
(sinhala), Euphorbia antiquorum - Daluk (sinhala), Acacia leucopholea -Katu
andara (sinhala), Prosopis juliflora - Kalapu andara (sinhala)
The coastal area has the highest population pressures and contains a number of
critical habitats. Coral mining, clearing of coastal vegetation, clearing of mangroves,
sand mining in beaches and coastal dunes, haphazard construction, and the dumping
of waste have led to pollution, coastal erosion and degradation of habitats. These
critical habitats are small and highly vulnerable to exploitation and degradation,
and need to be managed sustainably. The Coast Conservation Act of 1981 provides
for the management of the coastal zone and the appointment of a director (Coast
Conservation) for the implementation of the Act and to formulate and executes
schemes for coast conservation.

3.1 Population, Employment, Land Use - The Eternal Triangle

Growing pressure is being placed by people on the land resources. This has caused
increasing land degradation which remains a critical constraint on sustainable
development of the land resources of the country The man:land ratio is about
0.36 ha, though net per caput land availability is only about 0.15 ha. The remaining
0.21 ha per person is not readily available, because it is either designated for
conservation or has topographical or ecological constraints. Approximately 35 %
of the country is under agricultural usage and about 31 % under forest or wildlife
conservation areas. The remaining 34 % is under tea cultivation, pasture, patana
grass ( Chrysopogon zeylanicus ) and urban uses (Fig. 16.3 ).