Land Degradation Due to Soil Erosion

Degradation of land due to soil is of much concern because of its consequences on agriculture, which is major contributor to the country's GDP. Only about 31% of the total land area is arable. The contribution from land based activities to GDP has declined to 18% compared to 26% in 1978, due to diversify action of the economy. Many land use practices, past and present have reduced the productive capacity of soil and land in the country. The process of soil erosion commenced in the 19th century with the expansion of human settlement and cultivation of upland rain fed crops. This was aggravated by the changes in land use patterns during the British administration, when upper catchments of major rivers located in the central highlands were stripped natural vegetation to make way for plantation agriculture such as coffee and tea. Land clearing continued even after independence primarily for the establishment of human settlements. Some direct and indirect factors, that contribute to soil erosion are :

Comparative studies of erosion by zone have shown that mid country is the most prone to soil erosion. Out of 25 administrative districts of the country, in 07 the estimated land area under erosion is over 40% ( Kandy - 41%, Ratnapura - 42% , Moneragala - 42.5%, Hambantota - 42.8%, Badulla - 54.8%, Trincomalee - 55%, and Nuwara Eliya - 58%) both on site and off site impacts occur due to erosion.

Depletion of Coastal Resources

The coastal region includes an area of land and water where ecological processes of both land and maritime environments become interlinked and are influenced by human activities

Adverse impacts on the coastal resources include :

Although, Sri Lanka has one of the worlds comprehensive legal systems for coastal zone management laws alone, to safeguard coastal resources sustainable and limit their depletion has not brought about appreciable improvements. This is largely due to lack of political will and effective mechanisms required for implementing and monitoring such laws.

Loss of Biodiversity

Loss of biodiversity is due to several pressures arising from the following activities:

• Population increase and conversion to other land uses
• Removal of materials/species from the wild
• Competition between invasive exotic/domestic species and indigenous species
• Lack of understanding of scientific management
• Pollution
• Under-valuation of biodiversity
• Inequity in ownership, management and flow of benefits to community
• Legal and institutional systems that promote activities detrimental to biodiversity conservation
• The impacts due to loss of biodiversity can be categorized as
• Loss and degradation of natural ecosystem
• Loss of species and
• Loss of genetic material
  

Waste Disposal

Management of solid and liquid waste are critical issues particularly in urban areas around industrial sites. Although Local Authorities (LAs) are responsible for collection and disposal of waste, inadequate resource availability has hindered their work. A large quantity of hazardous and non- hazardous waste materials is generated at industrial and hospital sites. It is estimated that waste generation would continue to increase at a growth rate 1.2%. The present method of solid waste disposal is mainly open dumping in low-lying lands. Lack of sites for use for waste disposal has been a major impediment in resolving the issue. Numerous impacts of waste disposal that have been identified are: reduction in flood retention areas; pollution of wetland habitats, pollution of surface and ground water, creation of malodorous environments facilitating insect/mosquito breeding and other impacts on health.

Some LA's, NGOs, the private sector have initiated waste treatment practices such as composting of waste at household level, recycling of waste materials, incineration and landfills.

Inland water Pollution

Sri Lanka 's inland waters include man-made reservoirs, rivers, streams, ponds and marshes, constituting one of the highest densities in the world. Water pollution in the country arises from unwise agricultural practices with extensive use of agro-chemical and fertilizers, urbanization and industrialization resulting in ;