United Nations Environment Programme (UNEP)
 
 
 
Chapter 1 : Emerging Issues
 
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Land
 
Compared with other regions land is scarce and of poor quality. An increasing population has reduced the available land from 0.27 hectares per capita in 1976 to 0.25 hectares per capita in 1986 (ESCAP, 1992). The small island developing countries in the Pacific together represent less than 0.001 per cent of the total land area encompassed by the Exclusive Economic Zones. 

The majority of the developing countries in the region suffer from varying degrees of soil erosion and degradation mainly due to rapid rates of deforestation, poor irrigation and drainage practices, inadequate soil conservation, steep slopes and over grazing. According to the Global Assessment of Human-Induced Soil Degradation there are 1.9 billion hectares affected by soil degradation world-wide, 850 million hectares of which are within the Asia-Pacific region, accounting for about 24 per cent of the total regional land area. Thirteen per cent of arable land in the region is severely degraded, 41 per cent is moderately degraded and 46 per cent is lightly degraded (WRI/UNEP/UNDP/World Bank, 1996). Land degradation in the region can be categorized as: 

  • resulting from displacement of soil material, mainly through water erosion (61 per cent) and wind erosion (28 per cent), and
  • resulting from internal biophysical (2 per cent) and chemical (9 per cent) deterioration (see Figure 1.1).
Extensive and severe water erosion occurs throughout the Himalayas, South Asia, South-East Asia, large areas of the People’s Republic 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 severe water erosion, and in Sri Lanka 845,000 hectares are affected (FAO/UNDP/UNEP, 1994). Table 3 shows the areas affected by different degrees of water erosion in eight countries of South Asia. (see Table 3) 

In the dry belt stretching from central Iran to the Thar Desert of Pakistan and India, wind erosion causes extensive and severe land degradation. About 59 million hectares are affected by wind erosion in only eight countries of South Asia (FAO/UNDP/UNEP, 1994). 

More than 50 per cent of the world's irrigated land that has been affected by water logging and salinization is located in Asia and the Pacific. In addition, about 75 million hectares of soil in the region has deteriorated chemically over the last 45 years. 

Overall, 86 million hectares of land in the arid, semi-arid and dry sub-humid zones (including 70 million hectares of rain-fed cropland and 16 million hectares of irrigated croplands) have been affected by desertification (ESCAP, 1995a). The Asia-Pacific region has the largest population in the world affected by desertification. Altogether 35 per cent of the productive land in Asia has been affected, particularly in the People’s Republic China, Afghanistan, Mongolia, Pakistan and India. (see Figure 1.2) Figure 1.2 illustrates the relative importance of different causes of land degradation in the region associated with human activities, namely removal of vegetation cover, industrial activities, unsustainable agricultural practices, overgrazing by livestock and over-exploitation through construction of infrastructural facilities, etc. 

The human pressure on arable land in the sub-regions of the Asia-Pacific is illustrated in figure 1.3. (see Figure 1.3). South Asia has the highest average population density at 186 persons per square kilometre and the highest proportion of arable land, i.e. 39 per cent, and the lowest extent of forest cover, i.e. less than 20 per cent (FAO/RAPA, 1994). More than half the land area in South-East Asia is under forest cover and of the remainder only a small area is under permanent pasture and around 18 per cent is cultivated. The population density is high at 104 persons per square kilometre (compared with the Asia-Pacific average of 90 persons per square kilometre) but the availability of arable land is also higher, at 18 per cent, compared with the regional average of 15 per cent. East Asia has only 9 per cent of its area available as arable land and this is accompanied by a high population density of 120 persons per square kilometre. Approximately 45 per cent of the arable land area is pasture and 15 per cent is forest or woodland. Less than 10 per cent of the land area of the Pacific sub-region is arable, over half is permanent pasture, and around 15 per cent is forested. Most of the forests are found in the high islands of Melanesia (FAO/RAPA, 1994; ESCAP, 1993a and 1993b). 

Continuing population growth will put pressure on land resources. Increased dependence on intensive agriculture and irrigation will result in salinization, alkalization and water-logging in the irrigated areas of the region, particularly in countries such as the People’s Republic of China, India and Pakistan. If the newly irrigated lands, which are expected to increase by 96 per cent by the year 2000, are not managed properly, more cultivable soil will eventually become waterlogged and subject to salinization. Table 4gives a sub-regional analysis of trends and projections of degradation of crop and grazing land for the period 1960 to 2000. (see Table 4)  

In order to combat land degradation, several efforts have been made at the national and regional levels to develop monitoring and data collection methodologies and to formulate appropriate policies, programmes and projects. At the national level, such measures include watershed management, soil and water conservation, sand dune stabilization, reclamation of waterlogged and saline land, forest and range management and the replenishment of soil fertility in arable lands by use of green manures and cultivation of appropriate crops. 

In Nepal, various watershed management projects are being carried out by the Department of Soil and Water Conservation in critically affected or degraded areas, such as the Kulekhani Watershed Management Project and the Phewa Tal Watershed. Considerable success has been achieved in reducing the extent of land degradation in the targeted areas. Involvement of the local communities at every stage in the implementation of the projects has ensured the sustainability of the project and that measures would continue to be taken even after its completion. 

In India, watershed management programmes have also been implemented extensively. The Soil and Water Conservation Division in the Ministry of Agriculture plays a key role in the implementation of integrated watershed management programmes. These programmes are planned to cover 86 million hectares, of which 26 million hectares (27 river valley catchments and 8 in flood-prone rivers) in highly critical areas have been assigned priority under 35 centrally-sponsored projects. In addition, over 30,000 hectares of shifting and semi-stable sand dunes have been treated with shelter belts and strip cropping as a conservation measure. 

Similarly, Pakistan, Bangladesh and Bhutan have also been carrying out integrated watershed management projects, particularly in the high lands, to improve the condition of lightly degraded land and to avoid future degradation. Parts of the desertified lands in Pakistan have also been rehabilitated with plantations, and mobile sand dunes have been fixed with shelter belts and barrier fences. 

The People’s Republic of China has also achieved remarkable progress in some areas in controlling soil erosion through the implementation of water and soil conservation measures in eight different parts of the country since the State Council initiated a soil erosion control scheme in 1983. After 10 years of conservation efforts, erosion was brought under control over 2 million hectares, which constitutes a third of the total affected area of 6 million hectares (ESCAP, 1995a). The success of the scheme is evident from the fact that total grain output has nearly doubled as a result of improved land productivity. The second phase of the programme, covering the period 1993–2002, aims to introduce higher efficiency and quality in crop production (NEPA, 1993). 

Success in combating desertification has led to the rehabilitation of about 10 per cent of China’s desertified land in the past few decades and the deterioration of another 12 per cent has been halted in northern China. Afforestation at Yulin City in Shaaxi province, on the southern edge of the Muus Sandland, has brought over 330,000 hectares of shifting sand dunes under control and has protected 100,000 hectares of farmland; vegetation cover has increased 9.1 times over the period 1978–87. Combating desertification has recently been included in Chapter 16 of the Chinese Agenda 21 and approved by Central Government in April 1994. A further 20 per cent of the desertified land in the arid and semi-arid zones is targeted for rehabilitation by the year 2000 and another 32 million hectares severely affected by water erosion will also be brought under control (ESCAP, 1995a). 

Countries such as the Philippines, Thailand, Malaysia, Indonesia, Papua New Guinea, the People’s Republic of China, Myanmar, Nepal and Sri Lanka have already enacted laws to minimize the impact of mining activities on land degradation. 

 
 
 
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