INTRODUCTION ABOUT DISASTERS IN VIETNAM

Viet Nam is one of the most disaster-prone countries in the world. The table below describes the relative frequency of disaster phenomena in Viet Nam and it is clear, that most of the disasters are direct or indirectly water related (or caused by the absence of it).   

 Relative Frequency of Disaster Hazards in Viet Nam 

Viet Nam ’s near-uniformly high rainfall should provide sufficient water for most of its needs. However, water-related disasters are the most serious in Viet Nam and cause regular and substantial suffering, loss of life and economic damage.

The worst damage is caused by floods, particularly when accompanied by typhoons. Typhoons raise sea levels many meters and cause storm surges up estuaries, inundating valuable cropland. Typhoons destroy buildings with their high-velocity winds, and generate waves which can damage sea dykes protecting coastal land holdings. The torrential rains which accompany typhoons can cause flash floods, which come upon settlements unawares, and regularly submerge low-lying areas. The runoff from these typhonic rains, when added to rivers already swollen by monsoon rains, creates floods which endanger river dykes and threaten to devastate millions of households. On average, 4 to 6 typhoons reach Viet Nam each year, and hundreds of people are killed. It is anticipated that the number of heavy storms and typhoons to hit Viet Nam will increase both in number and intensity with global warming.  

One reason that water disasters are so serious is that most of the population lives in areas susceptible to flooding. This is because Viet Nam has developed as a nation by exploiting the low-lying river deltas and coastal lands for wet-rice agriculture.  Thus both the broad Red River and Mekong Deltas and the narrow connecting coastal strip of the country are prone to flooding from monsoon rains and typhoon storms.  Further, the remaining three-quarters of the country is mountainous and suffers from flash flooding.  As a result, over 70% of the population of Viet Nam is at risk of water disasters.
These natural disasters have been aggravated by inappropriate human activity. Along the coast, mangroves have been cut down and coral reefs have been mined, exposing coastal settlements to ever greater destruction by winds and waves. In the hills and mountains, deforestation has substantially increased erosion, siltation and runoff, so that peak flood levels are higher and arrive sooner than they used to. Because of the extra runoff in the rainy season, there has been less water infiltrating into the ground. This reduces dry-season flow downstream and leads to severe water shortage and sea water intrusion.
In addition, rivers whose flood plains are protected by a system of dykes, which confine floodwaters, have higher flood water levels than they had formerly. At present, during the wettest months, the Red River near Hanoi can have water levels five or six metres above ground level, whereas 1,000 years ago waters only rose 2 to 3 metres above ground level. The river and coastal dyke systems of Viet Nam are centuries old and suffer from piping, slides and local collapse, in spite of the strengthening and repair work done by hundreds of thousands of people mobilized every flood season.
Finally, non water-related disasters in Vietnam, while less common than water disasters, are having an ever-greater impact on the country. Vietnam ’s remarkable socio-economic and industrial development over the last ten years has increased the risk of technological accidents; industrialisation and population growth have put severe pressure on Vietnam ’s forests; climate change has led for the first time to drought in certain areas, thereby increasing risk of forest fire as well.