Don't rely too much on trees: Evidence from flood mitigation in China

Abstract

Combining a popular flood disaster dataset with climate data and satellite land cover data from China, this paper estimates how forests mitigate the frequency of flooding, resulting in two major findings. First, we confirm that an increase in forest area mitigates the possibility of flood occurrence even after controlling for socioeconomic and meteorological variables and time-invariant individual effects. Second, broadleaf trees and mixed-tree forests have a flood mitigation effect, whereas coniferous trees do not; these results are robust against alternative model specifications. This paper newly corroborates the concept of ecosystem-based disaster risk reduction. While there is an emerging consensus that ecosystems can mitigate natural disasters, there is limited evidence on how ecosystems mitigate disasters. To the best of the authors' knowledge, this study is the first to show that the type of forest is critical for mitigating floods in a rigorous econometric way (survival analysis) spanning numerous areas of interest.