Hazards and response

Hazards and response

Meteorological and Geophysical Hazards

Morgan's paper has primarily discussed the natural hazards. However, he limits himself to the meteorological and geophysical hazards of typhoons, volcanic eruptions, earthquakes and tsunamis. Landslides, which occur quite frequently in this region, have been omitted. In the 1950s, a huge landslide buried villages in the Dieng region in Central Java, and in late 1989, another large one occurred in West Sumatra. Many people were affected in this landslide. The landslides often disrupted road transportation as well. In unstable areas, human activities, such as road construction and rice fields, can intensify the risk. Many of the landslide-prone areas have been mapped.

Biological Hazards

Morgan has also ignored biological hazards, which are important in this region. Mosquitoes transmit many diseases, such as malaria, filariasis and dengue haemorrhagic fever; and schistosomes carry with them the debilitating bilharziasis disease. About 80 per cent of Indonesians harbour parasitic worms. Some diseases (malaria and dengue haemorrhagic fever) are widespread; others (bilharziasis) are localized. In Indonesia, only Java can be considered free of malaria, except for small pockets in coastal areas and some places in the mountains. Bilharziasis is found in an isolated area around Lake Lindu in Central Sulawesi, and in other places in Asia as well.

Some biological hazards (malaria and bilharziasis) are natural, although the spread and intensity of outbreaks are often influenced by human activities. The development of irrigation in Central Sulawesi, for example, has aroused concern among parasitologists that it may facilitate the spread of bilharziasis. Other biological hazards (cholera and hepatitis) are primarily the results of human activities, which are brought about by increasing population densities and unsatisfactory control of sanitary conditions. The diseases have caused misery and deaths, and the chronic nature of some have undoubtedly also reduced the productivity of many millions of people.

Human response to biological hazards has been researched in order to gain more understanding of the biology of the pathogens, their vectors and the physiological response of the human body to disease. The knowledge gained has been successfully used to control many diseases by vaccination, medication, eradication of the vectors by biocides and environmental engineering, and better health services.

Man-made Hazards

Man-made hazards are not discussed by Morgan, except those in the marine environment, although they are becoming ever more important in the region. Transportation and industries are important sources of pollution, and their rates of growth are high. Pollution can also occur as a result of accidents; some could be very serious: witness the Bhopal and Chemobyl disasters in India and the Ukraine respectively. The risk of tanker accidents is also not negligible in the regional seas.

Another man-made hazard is land subsidence which has been reported in Bangkok and Jakarta. These areas have become more prone to floods and, hence, will suffer from inundation by future sea-level rise.

Generally, pollution control is still weak in the region, and perhaps all metropolitan and industrial areas, with the exception of Singapore, are badly polluted. The extraction of underground water is also weakly controlled.

Potential Future Hazards

Potential future hazards are discussed by Morgan, and the sea-level rise has been singled out. However, he has discussed only inundation. But sea-level rise, if it indeed occurs, will also give rise to and/or intensify problems of seawater intrusion into rivers and underground aquifers, and of coastal erosion. The transmigration villages in the tidal areas in southem Kalimantan and eastern Sumatra (in which thousands of families from Java, Madura and Bali have been resettled) and the fish ponds along the long coasts of SouthEast Asia could suffer from both inundation and higher salinities. Salt-water intrusion could plague, for example, Pontianak in Kalimantan, which has periodically suffered from such a problem, and it could render the underground water of Jakarta useless; its quality is already sub-optimal because of salinity problems, presumably due to excessive extraction of underground water. Salt-water intrusion can also endanger the foundations of buildings. While the areas can be relatively easily protected from inundation-a very expensive undertaking-it will be much more difficult to cope with saltwater intrusion.

Another serious problem related to sea-level rise is coastal erosion. According to the Bruun rule, for each centrimetre in sea-level rise, the coastal line will retreat an average of I metre. Thus, with a 20-centimetre sea-level rise, which is considered plausible in the first half of the twenty-first century, the coastline will retreat by 20 metres. Therefore, coastal fish ponds, settlements, industries and hotels, among other activities and structures, which are located within 20 metres from the present coastline would be threatened, even though they would not be inundated.

It has also been predicted that climatic change resulting from global warming could increase the frequency and intensity of storms. However, the degree of uncertainly is still high. Intensive international negotiations, which formed parts of the preparations for the UN Conference on Environment and Development (UNCED) held in Brazil in June 1992, are now under way to reduce emissions of greenhouse gases, but there are still many difficulties before agreement can be reached. Some developing countries feel that they are being unfairly treated, and there are many uncertainties involved.

Still another potential future hazard, one which would affect the region and its people, is the so-called ozone hole which would expose the people to more Ultraviolet-B (UV-B) radiation. Although dark-coloured people are believed to be less sensitive than lightskinned people to the threat of skin cancer caused by UV-B radiation, the effect on cataract formation is known to be undiscriminating. The disease can be corrected by a simple operation, but many people in this region cannot afford such an operation and, hence, an increase in the number of blind people could occur as a consequence of the ozone hole. There are also indications that more UV-B radiation could reduce the yield of crops and fisheries.

There is general agreement that the cause of the ozone hole is the emission of chlorofluorocarbons (CFCs). The Montreal protocol is intended to reduce CFC emissions but, because of their long life, the ozone hole may well last far into the twenty-first century and beyond, even under the best circumstances.

Risk Perception and Assessment

Morgan has discussed at length the theoretical background of natural hazards and human responses. He correctly stated that there is still incomplete knowledge in the way people perceive and assess risks. Although many risks can be evaluated scientifically and objectively, subjective judgement still prevails and may often dominate. Traditional people, who constitute the majority of the inhabitants in this region, are willing to accept certain risks from natural hazards, partly because when a hazard strikes they consider it an act of God, and partly because resettlement somewhere else, if such is possible, brings new uncertainties which are considered more hazardous than the current risk they are facing. The resettlement by transmigration of the people on the slope of Mount Merapi and in Dieng, both in Central Java, for example, has met with considerable resistance. Many people who did transmigrate returned to their original habitation; the soils in the resettlement areas were less fertile than in their home villages.

Subjective assessment is also very common with educated people. For instance, accidents are far more likely to take place on roads than in nuclear plants, yet many people refuse to accept the risk of radioactive exposure resulting from relatively rare nuclear accidents, but they are willing to accept the far higher risk of death in road accidents.

Many studies have been carried out on risk perception, assessment and management. Since they are strongly influenced by culture and education, it would be useful for such studies to be introduced and/or strengthened in South-East Asian universities and research institutes, in order that policies for dealing with risk management can be based on more reliable scientific bases.