Assessment of hail suppression benefit on tobacco based on radar extrapolation

As one of the main tobacco cultivation regions, Southwest China features diverse terrain and experiences frequent hailstorms that seriously affect tobacco production, procurement, and the income of farmers. Hail suppression is an effective way to prevent and/or control hailstorms, yet most of its benefit assessment is based on comparisons between areas inside and outside the region of hail suppression. Objective and quantitative assessment is far less than sufficient. The present study constructs a hail yield loss model for tobacco. The hailstorm process on 1 July 2023 is taken as an example, and a detailed assessment of the economic benefits of hail suppression is conducted based on hail-related factors with/without hail suppression retrieved from radar observations and extrapolated data. Results are as follows. By comparing four regression models, an optimal relationship model is constructed between tobacco yield loss rate and hail maximum diameter, duration, and density. It is found that the log-linear regression model can effectively simulate tobacco crop damage caused by hails. Radar can reflect regional hail factors and tobacco hail damage at 1 km resolution. The yield loss areas and radar reflection areas of hails with larger diameters and longer durations are consistent. Using radar observations and extrapolated data, it is found that the hail suppression effect varies in different areas. The yield loss caused by hails can be reduced by up to more than 30% in nearly half of the hail suppression area. 1 Chinese Yuan (CNY) invested in the hail suppression operation during this hail process is able to bring about a tobacco loss reduction of 9.59 Chinese Yuan (CNY). This study provides a scientific basis for the research on methods of quantitative evaluation of economic benefits of hail suppression as well as financial benefits of meteorological services.