Coping with floods: A comparative study of strategies used in Vietnam, China and USA

Throughout history, rivers have provided people with ideal settings for development, which includes fertile farmland, water supply, convenient waterway for transportation and commerce, waste disposal and energy generation, which are essential for the expansion of human civilisation. Ironically, rivers often flood their banks, threatening the safety of the societies they support and causing, according to statistics, about one third of all deaths, one third of all injuries and one third of all damage from natural disasters. So how have societies coped with river floods in the past? What are the strategies and measures used and what are the historical, cultural, social, technical, managerial, economic and environmental justifications? What lessons can be leamt from their experience? To investigate this, 3 cases - Vietnam (Red River & Mekong River), China (Yellow River) and USA (Mississippi River) - with a long history of floods and whose economies can respectively be categorised as developing, newly industrialised and developed, were studied and a comparative analysis made. With topography comparable to the Netherlands, which is renowned for its success in coping with floods, the cases also offered an opportunity to see how population density and political situation may affect the strategies and measures adopted. The results of the study showed that living-with-flood, non-structural, and structural strategies are all used to cope with floods. The non-structural measures adopted by the 3 cases are essentially similar but differ substantially in content. Vietnam (Mekong) and China (Flood Storage Detention Areas) utilise the living-with-flood strategy more than USA, which has a strong preference for the structural strategy. In China, greater emphasis is laid on non-structural and structural strategies compared to the living-with-flood. This is best described by their catchphrase "Retain water in the upper reaches, Release it in the lower reaches and Detain it along the banks ofthe river". History, culture, political state, state of the economy, environment, and the way the society views flood control and water management were found to affect the strategies and measures adopted to cope with floods. The more the people appreciate the benefits and cultural values of the river and the land, the more likely they are to apply non-structural strategies and measures. When viewed mainly as key to economic development, prosperity and quality of life, there is a stronger emphasis on structural strategies and measures. There were 4 phases observed in the development of strategies and measures to cope with floods: a formation phase, growth phase, completion phase and perfection phase. These are respectively characterised by a predominance of the living-with-flood strategy; a combination of simple nonstructural and structural strategies; a predominance of structural strategy; and a balanced combination of structural, non-structural and living-with-flood strategies. The phase of a particular society is a direct function of the level, strength and state of its civilisation. A comparative analysis of more case studies was recommended to investigate whether the above 4phase- development model is also applicable to them. The study conc1udes that the Netherlands, as weIl as Kenya, can leam from the above case studies. One of the lessons leamt is that though flood dangers and impacts can be mitigated or alleviated by decreasing the probability of aflood value to be as small as economics and policy of coping with floods can justify, floods cannot be eliminated or avoided completely, as this probability can never be zero. However, by carefully studying each particular flood situation and focussing more on the Perfection phase, where the most suitable combination of measures from the 3 strategies are applied, we can continually improve the way we cope with floods.