|Natural Disasters in South East Asia and Bangladesh - Vulnerability Risks and Consequences (Centre for Research on the Epidemiology of Disasters - International Center for Training Exchanges in the Geosciences, 1998, 83 p.)|
|PART IV - SYNOPTIC ASSESSMENT OF NATURAL HAZARDS ON A NATIONAL SCALE|
The five types of territories prone to risks happen to be unequally arranged in the seven target countries (figures 34 to 37).
This country was formed, though late (1947 and 1971) around the delta of the Ganges and the Brahmapoutra but the historical capitals of Bengal were progressively moved towards the east: "the movement of the capitals is connected to the colonisation of the delta jungles by clearing" (SILBERSTEIN, 1995, p. 412). This displacement of populations towards the east is shown in figure 34, the coastal plains of Sundarban remaining associated with the mangroves contrary to the plains in the eastern part of the country whose development resembles that of the live deltas. The structure of the country reveals a symbiosis with the delta which moves itself towards the east; hence, a population that tends to expose itself to accumulated effects of cyclones and floods, the Bay of Bengal being marked by a positive anomaly of mean annual temperatures.
Floods are, indeed, an annual phenomenon in the Bangladesh with at least one third of the country that proves to be liable to flooding (BIMAL KANTI, 1997). In 1988, nearly 65% of the total surface area of the country was flooded (HOFER et alii, 1996, figure 38). During the 1987 floods, 51% of the precarious housing settlements of Dhaka were flooded, and the houses in these settlements were all practically destroyed (NAZRUL ISLAM, 1996, p. 381). Moreover, the mean track of the cyclones tends to deflect towards the North east, thereby affecting particularly the Chittagong coastal plains and the coastal mountains. The coastal mountains are populated by Buddhist, Animistic and Christian tribes that are in conflict with the Bangladesh army which is trying to find a way to control the very sensitive border with the Indian Union.
Myanmar perfectly illustrates the five territories prone to risks and the cultural polarization of the dominant populations on an inland basin. We find here the ancient capital cities of Burma like Mandalay, that are associated to Irraouadi, while the present capital, Rangoon, is an ancient Mort partially transformed into a garrison by the Burmese (LUBEIGT, 1997). It is worth noting that the Mthnic group is mainly found around Mulmein port in the Salouen delta. This is where "the only Mwho have kept their language and a certain nationalism referring to their brilliant pest" are to be found (BRUNEAU, 1995, p. 145). On the map and for these reasons, the Salouen delta, despite its physical characteristics, belongs to the marginal areas and resembles the coastal plains.
There is therefore a contrast shown between a present deltaic centre - the Irraouadi one that holds the capital city, is associated to intensive rice-growing and is exposed to danger of high frequency and intensity - and the coastal margins that show numerous minority ethnic groups. Mountains have been called according to minorities names: Chin mountains, Arakan mountains, Shan plateau (DE KONINCK, p. 206). A certain number of these ethnic groups occupy the mountain chains on the borders with the neighbouring countries. For example the Karen with Thailand, the Nagas with the Indian Union. This causes geopolitical problems. The geopolitical problems may be aggravated by the existence of ethnic groups belonging to the dominant cultures in the neighbouring countries: Bengalis Rohingyas of the Arakan plains of which 200,000 are political refugees in Bangladesh, Thais of the Shan mountains. BRUNEAU (1995, p. 163) points out that Thailand which was invaded by the Burmese in the 15 and 18 centuries "voluntarily favours a buffer zone along its border that is avoided by the Burmese army". The consequences of risk management by the Burmese government can be imagined. It happens that plains and coastal mountains are particularly exposed to cyclones, yet it concerns territories that are partially open to international trade (rubber, tin).
Just as in the case of Myanmar, Thailand illustrates the five territories prone to risks. The capitals moved from the inland basin, - with Sukhotai (1220-1377) then Ayutthaya, that was destroyed by the Burmese in 1767 - to the Menam Chao Phraya delta around the two forts of Thonburi and Bangkok. According to BRUNEAU (1995) "the central plain" -that is the inland basin - became the periphery of the centre". The Siamese dominate in the inland basin just like the delta and their Thai language is in reality the Siamese or "Thai of the centre".
This development as well as the predominance of the capital city increased the vulnerability to floods. The floods aggravated by the subsidence of the delta constitute a danger that slightly worries the local populations. They tend to culturally and economically value the presence of river water and make the best of floods. According to CLEMENT-CHARPENTIER (1995), on the initiative of people from western countries - who settled to the south of Bangkok, on the riversides -, the first street was laid out in 1861 on which Chinese trade rapidly grew. Up to then, all movements were by water, using the khlongs. According to a survey carried out by DANIERE and TAKAHASHl (1997) among 515 inhabitants from the shanty towns of Bangkok, flooding did not appear as one of the nuisances in the area. However, they insisted on the problems caused by bad water quality and the presence of rats and mosquitoes.
The minority ethnic groups are present on the territory margins: Laos of the Khorat plateau, 1.5 million from South Malay, 700 to 800,000 Khmers at the Cambodian border. It must be underlined that the coasts are affected by the development of international trade. Tourism, rubber plantations, aqua culture and fishing, particularly in the south, lead the Thailand government to develop the transport infrastructure, notably that near the Songkhla port on the Bay of Siam. These coasts are exposed to cyclones.
Laos shows a clear subdivision of two groups: the inland mountains in which the numerous minority ethnic groups dominate and the plains of successive basins of the Mekong where the low Laos are majority. The Mekong plains are associated to floods with the same culture ambiguities as those elsewhere in the continental South-east Asia. The country can be affected by tropical storms which result from the progressive attenuation of cyclones having crossed Vietnam. Difficulties in communication and ethnic group opposition - the country has experienced 30 years of civil war - render almost utopic every management of risk in a mountainous environment. Nevertheless, as was observed above, trying to open up the country to international trade, particularly with China and Thailand, is likely to improve the transport infrastructure in the axis of the high Mekong valley.
The five territories prone to risks identified in Myanmar and Thailand are found in this country. The Mekong delta starts, according to DE KONINCK (1994) to open itself at about 100 km to the north east of Phnom Penh, and at more than 400 km from the sea. Upstream, there is an inland basin around the Tonle Sap which is affected by the Mekong floods, whose waters force back those coming from the Tonle Sap. Once again, the Khmers, who are the dominant ethnic group here, developed, in a rather selective way, this central basin; they built so-called hydraulic or agrarian cities among which Angkor, while trying to get to the Mekong delta. Significantly, the present capital is found at the confluence of the Mekong and the effluent from Tonle Sap. The Khmer culture here again develops the river waters (ZEPHYR, 1997) which leads the populations to minimizing the effects of so-called abnormal floods (abnormal because of their intensity or frequency).
And there again, peripheral areas associated with minority ethnic groups, with coastal lines and highlands, can be identified. These are the coastal plains and mountains with Cham, Chinese and Khmer Islam minorities, the Chinese representing, despite the consequences of the Red Khmers period, one third of the coastal population. Here also the development of international trade, which promoted the Chinese minority, led the Cambodian government to develop the infrastructures: the Sihanoukville (Kompong Som) port was fully created in 1955 and linked up to the capital by rail. In the north, the plateaus have low population densities of the minorities called "Austro-asiatic mountain" people (BRUNEAU & GRUNEWALD, 1995, p. 180).
Vietnam, once again, shows a duality between territories populated by the Viets -two deltas, an inland basin in the prolongation of Cambodia, and coastal plains- and mountain territories that are the domains for minority ethnic groups. The two deltas are associated to the rival major cities of which one is the present capital, knowing that Hanoi is historically the first and that the Mekong delta was developed by a wave of successive colonisations. The southern peripheral parts of the delta remain associated to the mangrove coast and correspond to the limits of the pioneer fronts. Saigon even became the provisional capital of the Union in 1887.
The two deltas, particularly their cities, are primarily affected by the effects of the international opening-up and by the distribution of urbanization which results (DRAKAKIS-SMITH & DIXON, 1997). According to these authors, the effects of the opening-up, that are very unequally distributed, increase the vulnerability (fig. 39). They suggest that urbanization tends to weaken the management, and maintenance of the dyke networks, which, despite the numerous effects induced, protect the two cities from floods. Yet these cities, like the populations in the coastal plains, are hit by a high frequency of cyclones which can add their effects to those of floods. Ho Chi Minh-city "suffers the effects of the tides and faces a season of tropical rain causing flooding of large parts of the urbanized territory... The metropolis really lives with its feet in the water" (BOLAY et alii, 1997, p. 192).
The map shows a very different territorial structure distinguishing the very limited, small inland basins, and a domination of coastal mountains leaving little space to the coastal plains. Deforestation would therefore have, for the whole country, direct and major consequences on the dangers downstream. According to PARAGAS & CACANINDIN (1997, p. 29): "the destruction of forests and uplands endangers the watersheds and results in massive soil erosion, decline of soil productivity, sedimentation of river channels... catastrophic floods and acute water shortages during the dry season". These floods are favoured by a very high annual frequency of cyclones, between 5 (five) and 50 (fifty) during the period 1951-1985, even though they preferentially affect Lu and the side of this island exposed to the east. Moreover, earthquakes indirectly contribute to the floods that affect the coastal plains by way of tsunamis or by landslides. Landslides may temporarily block the rivers before giving way, thereby aggravating the intensity of the flood.
The floods here do not have the same cultural value as in continental Asia and the populations did not focus themselves on one or two principal hydrographic basins which we can straightaway understand from the name of the country. PARAGAS & CACANINDIN (1997, p. 31) notably insisted on the negative aspects of floods and cyclones: "flood damage is incalculable... the main effect of flood is to retard development". This has partly led the Philippines government to be much more vigilant to risk management. It leads to a better understanding of the shift observed in the intensity and frequency of natural hazards and the relatively lower number of victims recorded.