1. Population and environment seen from Rio
1.1 Environment issues at country level
1.2 Population aspects of environmental issues
1.3 Population and environmental policies
2. Land degradation and its factors in the region
2.1 Levels of degradation
2.2 Types of degradation
2.3 Causes of degradation
2.4 Per caput resources
3. Brief country profiles
1. Population and environment seen from Rio
1.1. Environmental issues at country level
Table 1 summarizes the environmental issues identified by countries of the East/Southeast Asia region in their national reports to the United Nations Conference on Environment and Development in Rio de Janeiro1/, and enables comparisons. The most common problems have to do with:
- air pollution (essentially under the impact of urban and industrial emissions);
- unhealthy or unpleasant aspects of urban environments (noise, congestion, waste accumulation);
- and water pollution, largely from industrial and domestic sources (but agricultural runoff is mentioned three times).
Next comes a set of problems affecting the agricultural resource base:
- ensuing soil erosion;
- and chemical degradation of soils (by a mix of agricultural, domestic and industrial wastes).
Water scarcity, which is mentioned with equal frequency, is also connected to agricultural development issues since irrigation is a major user everywhere. Salinization, usually by intrusion of salt water in overused underground aquifers, is spreading in coastal areas.
Marine pollution (arising from oil and shipping hazards but also from the concentration of human settlements along the coasts) is a growing problem, especially in view of its effects on aquatic life and fisheries. Finally the loss of biological diversity is increasing with the destruction of natural habitats both inland (forests) and on the coasts (mangroves).
1.2. Population aspects of environmental issues
Population dynamics is mentioned by a majority of the country reports among the causes of environmental problems:
- China notes the high density of population with respect to arable land, and that continued population growth increases pressures on natural ecosystems and water resources. This compounds the difficulties inherent to a rapid economic growth under conditions of relatively backward technology.
- Indonesia mentions rapid population growth as a difficulty but only in general terms. The only specific problem identified is the absorption of arable land by expanding cities.
- The Republic of Korea points to intense rural-to- urban migration (the flow to Seoul is at "flood levels") and rapid urbanization, leading to overcrowding problems and urban poverty which adds to environmental difficulties.
- In Mongolia, population growth and urbanization outpace waste management facilities and other infrastructures, leading to pollution and water quality problems.
- Myanmar identifies impacts of population growth in the form of expanding shifting cultivation and growing difficulties to satisfy fuelwood and charcoal demand, leading to deforestation and destruction of mangroves.
- The Philippines report evokes rapid population growth and continued migration to urban areas, with "sprawling slums and squatter settlements" as a result.
- Vietnam does identify population pressure as an important factor in the over exploitation of soil and marine resources.
Other countries ignore the population dimensions--or their negative impact. The influence of population growth is implicit in the land use problems of Laos (expanding shifting cultivation, new human settlements)--but implicit only. Singapore signals that urbanization has already occupied half the national territory and is going on, but wishes to accelerate population growth.
To some extent, the environmental problems of the region can be ascribed to technological and economic factors (industrial production or mining methods, absence of controls on pollution, consumption patterns and living standards) rather than to population size or density as such. But population growth, and population concentration in the case of urban problems, certainly compound all problems when they do not trigger them.
It is population growth--in a context of more or less stagnant agricultural technology--which creates the need for additional cultivated areas, leading to shifting cultivation and forest clearing, often with dwindling fallow periods and insufficient fertilization, and subsequent soil erosion. It is also population growth--in a context of fixed water resources-- which brings about water scarcity and overexploitation of ground water reserves (at times with ensuing intrusion of saltwater in aquifers). The same applies to overfishing, overhunting, or disturbances caused to wildlife habitats by human settlements and economic activities.
1.3 Population and environmental policies
The recognition of the role of population pressure on resources does not necessarily lead (as far as UNCED documents are concerned) to statements on the potential role of population- oriented measures in alleviating environmental issues. Only two countries in the region refer to such a role, mentioning that slowing population growth has beneficial effects on the environment (China) and that intensifying population control efforts will strengthen other environmental strategies (Vietnam). No country mentions the aim of reducing the pace of urbanization. Singapore affirms the need to accelerate population growth, and Malaysia is known to favour a much larger population than it currently has.
In general the environmental policies described in the reports are highly sectoral and segmented. No or little overall vision of environmental issues and their linkages and synergies is detectable. Programmes are focused heavily on the development of legislation, establishment of natural reserves, bans on detrimental activities, issuance of technical standards, and the monitoring and enforcement of those technical measures. Environmental education also is a rather common feature of the ongoing and envisaged policies. At any rate, considering (a) the sometimes modest capacities for policy implementation, especially when it comes to rural territory management and monitoring, and (b) the delays inherently necessary for most of the measures described to have a clear impact, it is worth wondering whether acting inter alia to slow down population growth might not be just a support measure, but a relatively efficient way of tackling environmental problems (Shaw, 1989).
2. Land degradation and its factors in the region
Table 2 presents: (a) the main results of a worldwide assessment of soil degradation problems, the GLASOD project, for countries of the region covered by the said project (ISRIC, 1991); and (b) indices of land and forest resources per caput, drawn from a UN data base (UN, 1994).
2.1 Levels of degradation
At the global level, 15 percent of the land area (around 1989) was found to be degraded by human activities. Half of the countries in this region are close to the world average, but several are much more degraded--some twice as much like China, DPR Korea or Vietnam, or even close to triple like Thailand. Only Laos is markedly better off than average from this standpoint. (The proportion degraded for Asia as a whole is 18 percent.)
It is also well to consider the varying intensities of degradation. The situation of Thailand and Vietnam--respectively with about 30 percent and 20 percent of their lands strongly or extremely degraded--is quite serious. Problems in Cambodia and the Philippines are also worrying insofar as virtually none of the degradation detected is of the benign kind.
2.2 Types of degradation
Soil erosion under the action of water (rain, streams and floods) is the main form of land degradation in East and Southeast Asia--like in the rest of the world. The only exception here is Mongolia (and part of China), where particular physical and climatic conditions result in significant wind erosion.2/
Chemical degradation, which accounts for 12 percent of global soil degradation only, represents a much higher share of the problems in some of the countries reviewed here (Vietnam, Myanmar, the Republic of Korea and Thailand in particular). This form of degradation essentially includes the loss of soil nutrients3/, salinization4/ and pollution. Finally, physical degradation5/ has little or no incidence, except in Malaysia.
2.3 Causes of degradation
GLASOD has also identified for each degraded area the main "causative factor" of the local problems:
- Deforestation is by far the main factor in the countries covered here: with the exception of Mongolia, all are above the regional average of 46 percent (and the world average of 36 percent), most of them (Laos, Philippines, Thailand, Cambodia, Malaysia, Vietnam, Indonesia) much above.6/
The role of population dynamics vis-a-vis other factors in deforestation is a much debated issue. In Asia, forest felling has for a long time been driven mostly by commercial operations based on the high value of hardwood (viz. teak). Later, with limitations or bans on these operations and the acceleration of population growth, the latter certainly has taken on an increasing importance (see part 3 below).
- Overgrazing has a very limited incidence in the region--again except for Mongolia--especially if compared to the world average incidence of 35 percent.
- Finally, land mismanagement (column agricultural activities) has an unusually high impact in half of the countries reviewed here (Republic of Korea, Mongolia, Myanmar, Indonesia and Vietnam: compare with the world average of 28 percent). This factor includes e.g. the cultivation of fragile soils, undue reduction of fallow, unwise use of fire, irrigation of inadequate soils, or diversion of rivers for irrigation.
It is worth noting that such practices usually occur only under constraining circumstances, including population pressure which is often responsible for the saturation of good lands leading settlers to cultivate inadequate (shallow, sloped, infertile) soils, or ploughing fallow land again before it has recovered its fertility, or attempts to obtain multiple crops from unsuitable soils through irrigation, etc..7/
2.4 Per caput resources
The last two columns of Table 2 present indices of population pressure on key agricultural resources:
- The first regards arable land. In this respect availability varies widely--Mongolia has 13 times as much cropland per caput as the Republic of Korea and 8 times as much as China. Several countries have severely limited resources, namely the Republic of Korea, China, DPR Korea, Vietnam, Indonesia and the Philippines (between 0.05 ha and 0.13 ha, while the world average is 0.26 ha).
Interestingly, population pressure on cropland as measured by this indicator is very weakly correlated with the degree of land degradation, in general and in this group of countries. Several factors may enable a population to obviate this constraint to some extent, e.g. appropriate agricultural technologies or the ability to rely on non-agricultural activities for income and on imports for covering agricultural commodity needs.
- Forest and woodland resources availability vary even more: Mongolia has about 60 times as much forest area per caput as China, and Laos--the only other country with ample resources--about 30 times. At the other end, the Republic of Korea, Vietnam, the Philippines and Thailand accompany China in the group of countries whose resources have dwindled to a preoccupying level (between 0.11 ha and 0.26 ha, while the world average is 0.76 ha). Korea DPR, Indonesia and Myanmar are in an intermediate situation.
3. Brief country profiles
The natural resources of China are not particularly abundant, at least in per caput terms. Water resources amount to 2,400 cubic meters (m3) per caput per year. This modest supply (less than a third of the world average) is expected to drop to 1,800 m3 in 2025 (based on the UN medium population projection). It must also be considered that the supply is heavily concentrated in the sparsely populated southwest of China. With increasing water use by agriculture, industries and cities, inland resources are overextended. More than 200 major cities lack adequate water, and some 50 of them face acute shortages. Beijing is seeking new sources of supply hundreds of kilometers away. Pollution of local aquifers by industrial and domestic wastes compounds the supply problem. By the year 2000 China will need an estimated 2,000 additional water treatment plans (Engelman and LeRoy, 1993).
The area of land suitable for agriculture is slowly decreasing, from 112 million hectares in 1957 and 104 million in 1965 to about 96 million hectares in 1990 (less than 2/3 that of India). The per caput arable area has fallen by half since 1957. It is estimated that 300,000 ha are lost annually to urbanization. More than one third of the rangelands are overgrazed, and the consumption of forest products exceeds stock growth by 20 million m3 annually (Jing Neng Li, 1993).
The expansion of agriculture to the less suitable slopes has been traced by researchers over six centuries and found to be driven by population growth. Deforestation was already serious by the mid-20th century (when the Great Leap Forward had reforestation as one of its objectives). Subsequently the growth in agricultural production was sought through intensification rather than through land development. But the heavy reliance on fuelwood, and some amount of conversion into farmland, continued to take their toll on forests. Also, intensification brought about other problems since, despite some punctual successes in "ecological agriculture", the typical side effects of irrigation, fertilization and pesticide use have often developed.
At the national level, industry certainly is a dominant factor in environmental problems: quite often, obsolete technologies lead to excessive use of energy, basic products (minerals etc.) and high emission of pollutants. Energy production itself, based on huge consumption of coal, is highly deleterious. Overall, it has been estimated that economic losses and damage to the environment in the various economic sectors amounted to some 7 percent of the GNP in 1992--about twice the level estimated in highly industrialized countries such as Japan and the USA. The Government admits that the economy must evolve towards a low resource consumption model, and that this will require both efforts by the administration and involvement of the masses (Shen Yimin, 1994).
The population, despite a moderately low growth rate, still increases at the pace of 13 million annually. The official policy lists reduced environmental pressure as one of the benefits of lower fertility and slower growth. But the issue is obviously more complex. Human concentrations on a relatively small part of the national territory and in cities with inadequate infrastructures pose a continuing problem, the demographic aspects of which are difficult to tackle. Strikingly, when it comes to outlining specific policies for the classical three broad regions (eastern coastal/developed; central/developing; western/underdeveloped) documents address very well the different economic and environmental priorities, but say nothing on possible demographic support policies.
Land degradation in Indonesia is caused by a mix of deforestation and improper agricultural practices (cf. Table 1). Deforestation is mostly due to land conversion to agriculture either by small farmers or under public investment projects--in particular under the Transmigration Program--as shown below (World Bank, 1990):
|Sources of deforestation|
Java, with its high population density and virtually all land in productive use, is the most affected island. In the uplands the eroded part expands at the rate of 1 to 2 percent annually and covers about one third of the cultivated area. Population growth there is rather lower than at national level, but some 150,000 farming households are still added each year. Holdings are very small and do not enable investing in conservation measures.
As for improper agricultural practices, they have to do for instance with extensification on environmentally sensitive drylands in mountain areas, which is certainly driven by rural population growth (and poverty, which is itself related in part to high population/resources ratios). It has also been noted that urban growth in Java has involved the expansion of dryland farming onto upland slopes without adequate safeguards, and increased environmental stress through waste production and disposal (Jagannathan, 1990).
Various groups contribute to the spontaneous expansion of agriculture in Indonesia: traditional shifting cultivators who have grown out of their lands, "wilderness settlers" (locals, immigrants and agents of wealthier investors) and, increasingly, the spillover from Transmigration Program settlements (Government of Indonesia, 1985). The areas most endangered are the upper part of watersheds in densely populated regions. Erosion damages downstream river beds and irrigation structures; but the greater loss occurs to agricultural productivity due to soil depletion in those watersheds. The cost of soil erosion on Java alone has been estimated at $350-420 million annually, with 80 percent attributed to on-farm productivity losses and the rest to siltation of rivers, dams and canals downstream (World Bank, 1989).
In Indonesia also, population policy has aimed to slow population growth, with good success. But this was clearly not enough to alleviate pressure on natural resources in the densely populated Inner Islands. This led successive authorities and Governments since 1905 to promote resettlement to the Outer Islands. About 3 million may have been resettled in this way during this century. Among these, there have been returns to areas of origin, but the phenomenon is not well measured. There have also been spontaneous migration flows to the newly developed areas (also not well known).
Studies show that the transmigration program has resulted in substantial deforestation, but illustrate the point that deforestation must be seen in context: the initial amount of forest cover must be taken into account, and this was and remains much higher in the Outer Islands; also, the value one places on an intact forest cover must be compared with the value of a transformed environment (e.g. in agricultural production).
The criteria for such a comparison must be clear and comprehensive, and Government bodies are the right place to make such choices taking into account long-term national interests. The population of Indonesia continues to grow at the pace of 3 million per year. Accommodating that growth in a sustainable manner clearly requires ever more careful planning.
The Philippines are highly susceptible to environmental damage because of their mountaineous terrain, fragile soils, and climate. Indeed, they probably suffer all the types of damage that could conceivably be feared to take place in that setting: deforestation, soil erosion, watershed abuse, disruption of water systems, and degradation of marine resources, including destruction of mangroves and coral reefs. A dominant factor is deforestation, which triggers a series of interlinked problems down the slopes and streams to the sea.
Deforestation was initiated by colonial logging operations: on Luzon, the bulk of deforestation took place before 1920; on Cebu, a logging ban was decided as early as 1870 in view of soil erosion problems. Overall, however, the US colonial rule (from 1904) accelerated deforestation by the introduction of modern logging methods. Settling in deforested areas became common under the pressure of population growth on lowland areas; with time, settling indeed became the main driving factor. In the 1960s and 1970s (after the peak of logging for export to Japan), population growth rates of up to 8 percent were observed in immigration areas.
Rapid population growth at the country level certainly was an important factor in this process, enhanced by unequal land distribution, poverty, lack of non-agricultural income opportunities and poor development policies. The development of export crops also was determinant in the land extension that almost doubled the cultivated area between 1960 and 1980 and reduced the forest area almost by half (Cruz and Cruz, 1990). But those crops also responded to the growing population's need for cash. Currently one third of the total population live upland, where half the area presents slopes that would require exceptional conservation works to support any cultivation. Critical watersheds are damaged, disrupting and loading rivers with silt while there is a growing need for irrigation, hence for stable water regimes. In fact, agriculture increasingly suffers from water deficits.
Coastal areas are vital for this populous country with an extremely long coastline. They used to be highly productive, supporting at least one fourth of the population. But the development of coastal towns and industries, the destruction of mangroves, the degradation of water systems, have grossly depleted the fisheries. Total catch has levelled off at 2 million tons, while it is projected that 4 million tons would be needed in 2020 (Myers, 1992).
Although growth has slowed somewhat, 1.4 million is still added to the country population yearly. The policy aims not only at further slowing the overall growth but also at halting the "exodus" to urban and coastal areas. This goes in the right direction as far as some environmental problems are concerned, but there remains a problem of the highlands. The agricultural "frontier" is closing there, which means that threshold effects are impending: unless human pressure stops mounting, local ecological systems may collapse, putting the subsistence of a large population at jeopardy.
Vietnam has a rather high population density (over 220 hab./km2) and, as cropland covers only 20% of its territory, the density per hectare of cropland reaches 11 persons, the highest in southeast Asia (UNDP, 1995). At the same time the economy is still heavily natural resource-based. Rural population represents 80% of the total and most of it derives its subsistence directly from agriculture, fisheries and forestry. But agricultural productivity is generally low (rice yields, for instance, are less than half those of China) so exploitation is largely extensive, requiring continuous land clearing in increasingly sensitive areas.
By all accounts, natural resources are heavily affected. Forest degradation, generally indicated at the main problem, proceeds "largely unhindered" under the impact of arable land expansion, fuelwood consumption, commercial logging, shifting cultivation and fire damage (SRV, 1995). It is estimated to cause the loss of about 200,000 ha of forest each year out of less than 10 million hectares remaining standing (SRV, 1992).
Out of the total land area 31% is degraded, including 21% strongly or severely degraded. For the most part (2/3) this is due to deforestation itself, which enables or accelerates water erosion; the rest is due to various forms of inadequate soil management, causing chemical degradation (mainly acidification and salinization) or more erosion (Table 1).
Another crucial class of problems for a country such as Vietnam is the "destruction of wetland ecosystems, the careless exploitation of aquatic resources, the misuse of water resources and the reduction of biological diversity" (SRV, 1993). Indeed, "because of their fishery breeding and nurturing functions, the loss of wetland forests (mangrove and back mangrove) is in many ways more serious than that of the upland forests or watersheds" (World Bank, 1995).
All the relevant official documents designate population pressure as the main factor in the depletion of forest resources and degradation of soil quality (SRV, 1992), along with the "shifting agricultural practices of ethnic minorities, and unsustainable felling for logs and firewood" but also the legacy of "years of war [...] and the absence of effective corrective measures" (SRV, 1993). Population concentration in coastal areas is linked to the depletion of fisheries, loss of mangrove forests, pollution of water resources, and saline intrusions due to the overuse of aquifers (SRV, 1992). Another type of problems is that of urban environments, characterized by water and air pollution from unchecked industrial and domestic sewage, with distinct health implications. Population pressure in this case contributes to growing imbalances between pollutant production and the limited sewerage and water treatment facilities (SRV, 1992).
Population research however does not go beyond the concern for the overall pressure of human numbers on natural resources, social infrastructure or investment resources. Little attention has so far been given to finer aspects of population dynamics such as differential growth by geographic area, by socio-economic category, by ethnic group or by age group. The patterns of migration and their role in urbanization seem insufficiently known, as is the way population movements affect infrastructure use or the shaping of markets.
The population of Vietnam grows at the pace of 1.6 million a year--half the absolute increase of Indonesia on a land area six times smaller. The rapidity of this increase in pressures on resources will require closely studied strategies, in particular as regards marine resources (which will be ever more critical in view of their exposure to the impact of rapid urbanization and uncontrolled industrialization).
Cruz, W. and M.C. Cruz (1990): "Population pressure and deforestation in the Philippines", ASEAN Economic Bulletin, vol. 7 no. 2, pp. 200-212.
Engelman, E. and P. LeRoy (1993): Sustaining water. Population and the future of renewable water supplies. Washington, Population Action International.
Government of Indonesia (1985): Forest policies in Indonesia. Jakarta.
ISRIC (1991): World map of the status of human- induced soil degradation. Global Assessment of Soil Degradation (GLASOD). Nairobi, UNEP.
Jagannathan, N.V. (1990): "Poverty-environment linkages: case study of West Java". Washington, The World Bank.
Jing Neng Li (1993): "Significant impacts of population growth on economic development and the environment in China", in Population, environment and development, pp. 88-95. New York, UN.
Myers, N. (1992): Population, resources and the environment. The critical challenges. New York, UNFPA.
Shaw, R.P. (1989): "Rapid population growth and environmental degradation: ultimate versus proximate factors". Environmental Conservation, vol. 16 no. 3, pp. 199-208.
Shen Yimin (1994): "An initial look into China's population, environment and sustainable development". Cairo.
SRV (1992): National Report to the United Nations Conference on Environment and Development.
SRV (1993): Vietnam: a development perspective. Prepared for the Donor Conference.
SRV (1995): "Viet Nam National Environmental Action Plan". Final draft. SRV/IDRC.
UN (1992): Nations of the Earth Report. UNCED National Reports Summaries. New York.
UN (1994): PRED Bank 2.0 Country Profiles. (Draft.) New York.
UNDP (1995): Environment and natural resource management. Strategy and action plan for UNDP Vietnam. 2nd edition.
World Bank (1989): "Indonesia--Forest, land and water: issues in sustainable development". Washington.
World Bank (1990): "Indonesia: sustainable development of forests, land and water". Washington.
World Bank (1995): Viet Nam. Environmental program and policy priorities for a socialist economy in transition. Two volumes. Washington.
The extent of the degradation problem and its patterns vary notably among regions:
- Africa has 25% of wasteland (the highest proportion among regions), 12% lightly or moderately degraded and 4% strongly or extremely degraded land (also the highest proportion). The main type of degradation by far is the loss of topsoil (76% of the degraded area) followed by the loss of soil nutrients (9%).
Burkina Faso, Burundi, Ethiopia, Madagascar, Lesotho, Morocco and Rwanda are particularly affected.
- North and Central America has 6% wasteland, 6% lightly or moderately degraded and 1% strongly degraded land. The main types of degradation are the loss of topsoil (75% of the degraded area) and terrain deformation from water erosion (16%, but 40% in Central America).
Costa Rica, El Salvador and Panama are the most affected countries.
- South America has 1% wasteland, 11% lightly or moderately degraded and 1% strongly or extremely degraded land. The main types of degradation are loss of topsoil from water erosion (39% of the degraded area), loss of soil nutrients (28%) and terrain deformation from water erosion (12%).
Brazil is particularly affected.
- Asia has 11% wasteland, 15% lightly or moderately degraded (the highest proportion among regions) and 3% strongly or extremely degraded land. Again the main type is loss of topsoil (71% of the degraded area), the next being terrain deformation (16%); salinization (7%) is significant. China, India, Thailand and Vietnam are particularly affected.
- Australasia has 11% wasteland, 11% lightly or moderately degraded and a negligible proportion of strongly or extremely degraded land. For 95%, degradation consists in the loss of topsoil.
- Europe has a negligible proportion of wasteland, 22% lightly or moderately degraded and 1% strongly or extremely degraded land. The main types of degradation are loss of topsoil from water erosion (61% of the degraded area) and compaction (15%).
The table below quantifies the area not affected by degradation or wasteland, as a proportion of total land area, by region.
Proportion of total area in stable and other terrain not
degraded by human action, wasteland excluded, by region.
North America...... 91% WORLD.............. 74%
South America...... 85% Asia............... 71%
Australasia........ 78% Central America.... 62%
Europe............. 77% Africa............. 59%
|EROSION||CHEMICAL DEGRADATION, POLLUTION||LOSS TO
|Shifting cultivation, fuelwood collection.||Overhunting, habitat destruction.||Mangrove destruction.|
|Due to deforestation.||Habitat encroachment.||Depletion of groundwater.||Vehicles and forest fires.||Shifting cultivation + logging = depletion.||Inadequate disposal of domestic/indus-trial wastes.|
|Over-exploitation, deforestation.||Salinization especially in deltas. Pesticides, fertilizers.||Industrial and domestic wastes.||Industrial and domestic wastes.||Animal resources overused. Habitat loss.||Very serious. Wastes end up in sea.||Overfishing.|
|Due to loss of wooded cover.||Heavy metals. Acidification, salinization.||Depletion of groundwater.||Domestic/industrial/agricultural waste water.||Intrusion of salt-water||Power plants, industries, transport.||Rapid loss (logging + agricultural expansion).||Deforestation, habitat disturbances, illegal trading.||Crowding, traffic congestion, hazardous waste.||Damage to mangroves, coral reefs.|
|Toxic wastes (chemical industries, electronics).||Rapidly growing demand.||Siltation.|
Industrial waste (heavy metals).
|Cities, transport, industries, forest fires.||Solid waste.||Oil spills, dumping in straits.|
|Insufficient freshwater supply.||Illegal exploitation.||Oil spills.|
|Cultivation of slopes, deforestation.||Construction, quarrying.||Insufficient clean water supply.||Wastes, fertilizers, pestic. Eutrophication.||Salt-water infiltration.||Oil combustion + coal.||Conversion to agriculture, logging.||Habitat disturbance, chemical pollution, etc.||Several cities overcrowded.|
|Soil erosion on deforested slopes.||Industrial/ domestic wastes.||Industrial/ domestic wastes + mine tailings.||Salt-water intrusion.||Rapid depletion.||Sprawling slums/squatter settlements.|
|Industrial discharge, poor sewerage.||Especially SO2 from vehicles.||Noise. Waste disposal is problematic.||Chemicals and oil from ships.|
|Erosion and desertification.||Shortages for industrial and domestic uses.||Coal burning (acid rains).||Infrastructureoverburdened.||Marine pollution.||Overfishing.|
|Agriculture, deforestation Hard climate.||Reduced water levels. Lakes drying up.||Wastewater discharges, urban runoff.||Serious. Industries, vehicles, refuse burning.||Agricultural encroachment. Fires.||Several species threatened.||Hazardous wastes.|
|(Some)||(Mining)||Agricultural runoff pollutes inland fisheries.||(Coal burning)||(Some)|
|Pesticides, fertilizers, industrial wastes.||Rivers polluted by wastes.||Traffic.||Congestion. Noise. Capital crowded.||Wastes brought by rivers. Eutrophication.|
|Level of degradation (%)||Types of degradation (%)||Cause of degradation (%)||Cropland|
per caput (ha)
1/Such reports were presented by all countries covered by the CST Bangkok except Cambodia. See UN (1992).
2/Globally 83 percent of land degradation takes the form of erosion: 70 percent mere loss of topsoil and 13 percent more severe terrain deformation.
3/Either through depletion--from cultivating poor or mediocre soils without sufficient fertilization--or through erosion.
4/Typically, from inadequate drainage (or water quality) in irrigated areas, or from salt water intrusions.
5/Mainly soil compaction and waterlogging, which affect less than 5 percent of degraded areas worldwide.
6/For the purpose of Table 2 "deforestation" includes overexploitation of woodlands for domestic uses.
7/For a comparison of land degradation patterns among the main regions of the world, see Annex.