Managing Arid Areas and Sand Dunes in Sri Lanka - Combating Desertification in Asia, Africa and the Middle East - page 333

Fig. 16.14 Community consultation is an important part of the development of land use plans

7.1 Climate Change and Its Impacts on Agriculture, Forestry

and Water

Since the most significant land degradation process occurring in Sri Lanka is soil
erosion due to rainfall, studying the effects of climate change on soil erosion is
vital. Higher rainfall intensities not only enhance splash erosion, but also generate
higher surface runoff. The final result is enhanced soil erosion, leaching of plant
nutrients along with off-site effects such as deposition/siltation and flash flooding.
Moreover, extreme rainfall events can trigger landslides although those are also
related to the spread of human settlements into unsuitable areas which are prone to
landslides. In contrast, low rainfall situations can create higher atmospheric water
demands resulting in higher evapo-transpiration. Higher evapo-transpiration can
aggravate salt accumulation in lowlands resulting in abandonment of cropping. This
situation will be more apparent in dry and coastal areas. On the other hand, increased
temperature will alter soil chemical, physiochemical and biological environments,
out of which the most apparent would be the increased rate of degeneration of soil
organic matter, which results in enhanced soil erosion. Furthermore, the temperature
rise will increase the situations with salt affected soils, resulting in loss of lands from
agriculture. Water logging conditions and sea water intrusions which are associated
with coastal zones are expected to be on the rise due to increase in sea water
levels. Loss of land due to rise of sea level would also be significant for Sri Lanka.
Curtailing land degradation in the face of possible scenarios of climate change is
essential (Wickramasinghe and Munasinghe 2009 ).