Major Environmental Concerns  

[ Land | Forest | Biodiversity | Water | Marine & Coastal Environments | Urban & Industrial Environments ]

Underlying Causes

[ Social | Economic | Institutional | Environmental ]

The region's land resources have been divided into low and high agricultural production potential. The region is characterized by relative land scarcity and poorer land quality than other regions. Due to increasing population, the available land decreased from 0.27 hectares per person in 1976 to 0.25 hectares in 1986 (ESCAP, 1992). Land availability in the small island developing countries is severely limited.

In most developing countries in the region, soils suffer from varying degrees of erosion and degradation mainly due to rapid rates of deforestation, poor irrigation and drainage practices, inadequate soil conservation, steep slopes, and overgrazing. According to the Global Assessment of Human-Induced Soil Degradation, of the world's 1.9 billion hectares affected by soil degradation, the largest area (850 million hectares) is in Asia and the Pacific, accounting for about 24 per cent of the land in the region. Thirteen per cent of arable land in the region is considered to be severely degraded, 41 per cent moderately degraded, and 46 per cent lightly degraded (WRI/UNEP/UNDP/WB, 1996).

Land degradation in the region results from displacement of soil material, mainly through water erosion (61 per cent) and wind erosion (28 per cent), and from biophysical (2 per cent) and chemical (9 per cent) deterioration (UNEP/ISRIC, 1990).

Water erosion is extensive and severe throughout the Himalayas, South Asia, South-East Asia, large areas of China, Australia, and the South Pacific. In India alone, 12.62 million hectares out of a total of 32.77 million hectares of agricultural land is affected by strong water erosion; in Sri Lanka, 845,000 hectares are affected; and in Iran, 45 per cent of agricultural land is affected by light to moderate water erosion (FAO/UNDP/UNEP, 1994).

Wind erosion is extensive and severe in the dry belt stretching from central Iran to the Thar Desert of Pakistan and India. The wind-eroded land in eight countries of South Asia alone is about 59 million hectares (FAO/UNEP/UNEP, 1994). More than half of the world's irrigated land affected by waterlogging and salinization is located in Asia and the Pacific, while some 75 million hectares of soil in the region have deteriorated chemically over the past 45 years.

Overall, 86 million hectares of land in the arid, semi-arid, and dry subhumid zones-70 million hectares of rainfed cropland and 16 million hectares of irrigated croplands-have been affected by desertification (ESCAP, 1995a). This implies that altogether 35 per cent of productive land in Asia is now desertified. The region has the largest population in the world affected by the process. The countries suffering most from desertification are China, Afghanistan, Mongolia, Pakistan, and India.

The contribution of human activities to land degradation in the region has been estimated as follows: removal of vegetation cover, 37 per cent; overgrazing by livestock, 33 per cent; unsustainable agricultural practices, 25 per cent; and overexploitation through construction of infrastructure, 5 per cent (UNEP/ISRIC, 1990). (See Figure 2.6.)

Population pressure on arable land in various subregions of Asia and the Pacific is considerable. The average population density for the region is 90 persons per square kilometre, and 15 per cent of the total land area is considered arable. The equivalent figures for the four subregions are as follows:

• 186 persons per square kilometre and 39 per cent arable land for South Asia;
• 104 persons per square kilometre and about 18 per cent arable land for South-East Asia, which also has more than half the land area under forest cover;
• 120 persons per square kilometre and 9 per cent arable land for East Asia, where approximately 45 per cent of the land area is pasture and 15 per cent is under forest or woodland; and
• 3 persons per square kilometre and less than 10 per cent arable land in the Pacific subregion, with more than half being permanent pasture (FAO/RADA, 1994; ESCAP, 1993a and 1993b).

Population growth will continue to pressure land resources. Increased dependence on intensive agriculture and irrigation may result in salinization, alkalization, and waterlogging, particularly in irrigated lands that are not managed properly. This is a serious concern in the region, especially since irrigated lands are expected to increase significantly in the near future.

United Nations Environment Programme