Geoscience Reference
In-Depth Information
result from changes in moisture levels, an increased incidence of pests and
growing spoilage of agro-products as a result of enhanced microbial activity.
These effects could result in reduced yields and shifts in productivity. On
the other side, irregular patterns of rainfall and high seasonal concentrations
in Sri Lanka's Central Highlands, with attendant increases in run-off ratios,
could result in soil erosion, land degradation and the loss of productivity of
plantation crops. Hydropower generation in Sri Lanka in June 2012 dropped
by 14.8% 323 GWH due to receding water levels of hydropower reservoirs
due to less rainfall (Abeywicreama 2012). Therefore, these issues may need
to be addressed more through laws and regulations, while at the same
time taking into account developmental needs. In this context, balancing
enforcement measures with awareness and training through assistance
programs appears to be a big challenge for the relevant authorities (Ministry
of Environment 2010).
Deforestation
Sri Lanka has a striking variety of forest types brought about by spatial
variations in rainfall, altitude, and soil. The forests have been categorized;
wet sub-montane forests (at elevations between 1,000-1,500 m in the wet
zone); wet montane forests (at elevations of 1,500-2,500 m); with reverence
vegetation along river banks; the wet lowland forests transform into sub-
montane and montane forests (UNESCO 2012).
The present natural forest cover of Sri Lanka is a little less than 25%
of the total land area (Ministry of Forestry and Environment 1999). In the
1880s, the forest cover was estimated to be still around 80% of the country's
area. However, during the colonial period, mostly tropical montane forest
and tropical moist evergreen forest cover rapidly decreased. By the time
the British left the island in 1948, the forest cover was down to about 54 to
50%. In fact this trend has accelerated after independence; largely tropical
lowland wet evergreen, tropical dry mixed evergreen and riverine forest
have continually been reduced from about 44 to 24% from 1956 to 1992
due to resettlement programs. Considerable areas of the forest were also
submerged by the hydropower reservoirs that were constructed during the
past three decades under the Accelerated Mahaweli Project (Ministry of
Forestry and Environment 1999). The average rate of deforestation between
1956 and 1992 was approximately one km
2
per day (Hewawasam 2010).
After 1992, large parts of the forest patches in the Central Highlands were
cleared to expand towns and villages and to develop infrastructure facilities
(Fig. 15.4, Table 15.1).
Search WWH ::
Custom Search