# Statistics on Typhoon Intensity and Rice Damage in Vietnam and the Philippines
## Discussion  
### Rice Damage Not Solely Due to Strong Winds  
There was a weak relationship between landfall wind speed and the three indicators of rice damage, which suggests that rice damage was not primarily due to strong winds. The relationship between ACE and rice damage was also poor, which confirmed that typhoon wind speed was not the sole reason behind the amount of rice damage in the two countries. [PERSON] et al. [3] used a regression model to quantify the relationship between tropical cyclone-induced direct economic loss and maximum wind speed in China. Their results from 2000 to 2015 showed that the log of the loss rate was linearly correlated with the log of TC intensity, and a doubling in maximum wind speed had increased TC-induced economic losses by 225%. In contrast, our findings showed that landfall wind speed was not a significant determinant of rice damage in Vietnam and the Philippines, even though strong winds may cause the rice plants to lodge. Rice grains may also be striped, and the plant is subjected to water stress [6; 15]. In the case of Vietnam, principal component analysis (PCA) using landfall wind speed and central pressure revealed that Typhoon Doksuri was the strongest among all the typhoons that affected Vietnam from 1977 to 2001, and this was followed by Typhoon Cecil in 1985, Xangsane in 2006, and Damrey in 2017 [22]. Our review showed that Doksuri, Damrey, and Cecil only damaged a relatively modest area of rice that ranged from 4487 ha to 20,000 ha. For typhoon Xangsane, the information for rice damage was combined with other crops and, thus, was excluded from our analysis. The lack of a relationship between typhoon wind speed and rice is possibly due to the stronger cyclones missing the vulnerable growing and harvesting periods for rice. Rice plants were the most vulnerable to wind speeds of between 8 and 70 km/h at the heading stage and 14-30 days after heading [5], and it was possible that most typhoons may have occurred when the rice plants were less prone to wind damage. Several studies have showed that typhoon-induced rainfall was a significant factor in agricultural losses, and this may be the case in our study. For example, [PERSON] et al. [6] exposed two different rice cultivars to a passing typhoon and found that the upper parts of the rice plant had been soaked by the rain. As a result, the weight of the canopy was 1.3 times higher than in normal conditions. This made one of the rice cultivars they studied more susceptible to bending over. [PERSON] and [PERSON] [8] highlighted that heavy rain during ripening induced preharvest sprouting, while during the flowering stage, heavy rain increased the frequency of unfilled grains. In both cases, overall yields would be reduced. Heavy rain can also cause plants to be submerged and lead to a reduction in biomass as light interception is reduced and leaf growth is hindered [28]. As we were not able to obtain rainfall data, further work is needed to evaluate the extent to which rice crops are affected by typhoon-induced heavy rain. Additionally, it is possible that a combination of heavy rain and strong winds had an adverse effect on rice production, and work can also be conducted to de-couple the separate effects of strong winds and heavy rains on rice damage. At the same time, information on the growth stage of the crop at the time of the typhoon can also be incorporated to improve the analysis, as the impact of the typhoon is dependent on the condition of the crop. One metric that can be used to quantify the hazard posed by tropical cyclone rainfall is the Extreme Rain Multiplier (ERM). To determine the ERM, typhoon rainfall is expressed as a multiple of the climatologically derived two-year rainfall value. This index allowed researchers to identify damaging historically typhoon rainfall events that would have been classified as \"weak\" cyclones using wind-based metrics like the Saffir-Simpson scale [29]. The lack of rainfall data at a fine enough resolution would, however, limit the use of this rainfall metric.