Water Hazards, Resources and Management for Disaster Prevention:
A Review of the Asian Conditions
IDNDR 1991-1999

George Whitehouse
Chairman, Upper Parramatta River Catchment Management Trust, Australia

in association with
John R. Burton, Emeritus Professor AO, BE(Syd), HonDResMgt(NE), FIEAust, FEIA, CPEng.

for the Economic and Social Commission for Asia and the Pacific and the IDNDR Secretariat
March 1999

CONTENTS

This report is concerned with water-related natural disasters. A companion paper is being prepared on the topic of geology-related disasters.
 

The Asian and Pacific region extends over a total area of about 35 million square kilometres, or 26 per cent of the world's land area. With nearly 60 per cent of the world's population and over 60 per cent of the total irrigated land, the region is more densely populated and more intensely cultivated than elsewhere.

Natural disasters are estimated to have claimed about 3 million lives around the world in the past two decades, as well as severely affecting the livelihood of about 1 billion people. The damage caused to property has been assessed at well over US$ 400 billion. In 1990 The UN General Assembly declared the 1990s to be the International Decade for Natural Disaster Reduction, in which the international community, under the auspices of the United Nations, would pay special attention to fostering international cooperation in the field of natural disaster reduction.

At the beginning of the International Decade for Natural Disaster Reduction, worldwide bilateral and multilateral donor investment in development was estimated to be about US$ 50 billion. In the same year it was estimated that losses caused by disasters totalled US$ 47 billion, leaving a net balance of US$ 3 billion. Since then, the situation has not improved as natural disasters continue to exact their toll and hamper development efforts. Asia and the Pacific has been one of the worst hit regions of the world. It is estimated that more than 50 per cent of the world's major disasters occur in Asia and the Pacific.

Since the International Decade for Natural Disaster Reduction began in 1990, the total number of deaths caused by natural disasters in Asia and the Pacific has exceeded 200,000. The estimated total damage to property was already about US$ 50 billion until the Kobe earthquake in 1995 and very heavy flooding in China in 1995 and 1998. In the 1991 cyclone and storm surge event in Bangladesh, 140,000 people perished, whilst the flood of 1998 affected the lives of 25 million people. The total damage by the 1995 flood in Bangladesh was estimated at US$ 2 billion, the equivalent of 10 per cent of the gross domestic product (GDP) of that country. In that year, various provinces of China were affected by extensive floods during the month of July, affecting 220 million persons, taking 2,300 lives and causing a total loss of US$ 12.5 billion, equivalent to 4.5 per cent of the GDP of that country. The flood in 1998 in China was the most severe one in the past 44 years. According to governmental estimates, 223 million people - one fifth of China's population were affected, 3,004 people died and 15 million were made homeless. About 15 million farmers lost their crops. The floods caused severe damage to critical facilities such as health clinics, schools, water supply, and other infrastructure such as roads, bridges and irrigation systems as well as industrial facilities. At the end of August, direct economic damage was estimated at over US$ 20 billion. The total damages caused by floods in 1998 in the Region were estimated to be over US$23 billion.

Through such events, the national economies of developing countries in Asia are significantly affected by the loss of scarce resources that could otherwise have been used for social and economic development. In many cases the development process has been set back years or decades. The frequency and intensity of adverse natural phenomena and the extensiveness and severity of the damage they cause seem to be increasing over time.
 

Because of the continuing rapid population growth in the countries of Asia and the Pacific, people, mostly the poor, are being forced to settle at squatter areas in large cities, usually inhabiting low-lying flood-prone areas, unstable hillsides or other disaster- prone marginal areas owing to the high cost of suitable alternative locations and the extremely high cost of new infrastructure and services. In consequence, the number of persons vulnerable to natural hazards is increasing rapidly.

The principal reasons for the continuing increase in the loss levels caused by natural disasters include (i) the continuing growth of the population, (ii) the increase in building density by the growing concentration of people and the economic assets in urban areas, and (iii) a constant migration of people to coastal areas that are generally more highly exposed to natural disasters. For example, in Bangladesh over a million people are living on islands formed by silt deposits and along the vulnerable flood plains and coastal areas. Over 85 per cent of the population of China live on alluvial plains or along river basins concentrated in one third of the total area of the country. The situation is quite similar in Viet Nam, where the dykes along rivers providing protection are sometimes breached by flood waters causing extensive inundation. The development of industry in regions that are subject to natural hazards, without appropriate protective measures being taken, is another reason for the growing increase in the loss levels caused by natural disasters.

Natural hazards cause a high number of lives to be lost, but relatively small property losses, in the least developed and developing countries. In the relatively developed countries, on the other hand, where disaster prevention and mitigation measures are adequately established, the loss of lives is relatively small but the damage to property can be high. Losses may of course vary considerably within a given country.

China's structure of land use dictates the disaster composition of the country. In terms of the geographical extent of vulnerability, the bulk of farmland and pastures are the main areas threatened by natural hazards. In the event of a disaster, therefore, peasants and herdsmen are affected the most, and in case of a destructive disaster, thousands upon thousands of households may be adversely affected. However, in terms of total losses, those resulting from disasters in urban areas will usually be much heavier.

The effect of natural hazards on the loss of human lives is directly related to the poverty levels in a given country. National and regional efforts for natural disaster reduction should therefore be closely linked with poverty alleviation and economic and social development activities.

Another factor that exacerbates the effects of natural hazards is the environmental degradation taking place in many countries of the region. The damage caused by natural hazards is higher in countries where environmental degradation is rampant. Deforestation, erosion, overgrazing, overcultivation and incorrect agricultural practices and the degradation of natural buffers amplify the effects of natural hazards. Table 1 shows the relative intensity of hazards faced by some countries in Asia and the Pacific.
 

All in all, therefore, the potential for the occurrence of devastating natural disasters is much greater in the countries of Asia and requires particular attention if the severe toll of these events on life and property is to be significantly reduced. It is the purpose of this report to examine the extent of these disasters in further detail, to report upon the progress that has been made during the Decade to cope with the problems they bring, and to suggest improved ways and means of doing so.

Back to top   Next Section