Comparing cost-effectiveness of paddy fields and seawalls for coastal protection to reduce economic damage of typhoons in China

Abstract China suffers from typhoons frequently. The protection of the population and property of coastal areas from typhoon damage mainly relies on seawalls. As the largest artificial wetlands in China, paddy fields have been proven to provide some ecosystem services as natural wetlands do. However, the studies about whether paddy fields have the same typhoon protection function as wetlands are few. We assessed 138 typhoon events in China from 1989 to 2018 to establish three economic regression models and to demonstrate that the existence of either seawalls or paddy fields in the swath of the typhoon can reduce economic loss. In addition, we compared the typhoon protection value provided by seawalls and paddy fields, and analyzed their cost effectiveness to compare their efficiencies at mitigating the economic damage caused by typhoons. The results show that the average economic values of the protection from typhoon damage provided by seawalls and paddy fields are CNY 8.78 million/km and CNY 0.799 million/km2, respectively. Although the cost effectiveness of the typhoon protection provided by seawalls is 1.8 and that of paddy fields is 0.4, the typhoon protection value provided by paddy fields cannot be ignored despite their primary function is to provide food.