Abstract:

Based on the water temperature and crayfish yield data (2016–2023) from integrated rice−crayfish farming bases in Qianjiang, combined with air temperature data (1959–2023) from Qianjiang national basic meteorological station, through the correlation analysis between the number of consecutive days of daily maximum water temperature and the crayfish yield loss rate, the key disaster−causing thresholds of high−temperature disaster to crayfish were studied. By using a water temperature−air temperature regression model, an equivalent daily maximum air temperature threshold for high−temperature disasters was established. As a result, a heat disaster weather index was established and an insurance product was designed to provide a means of transferring heat disaster risks in crayfish farming. The results showed that:（1）when the daily maximum water temperature at a depth of 30 cm in the shrimp ditch reached or exceeded 31.5℃ for 7 consecutive days, it was the key disaster−causing threshold for high−temperature disaster.（2）There was a stable correlation between water temperature and air temperature during the high−temperature period (from April to October)，based on their relationship model, an equivalent meteorological index of the consecutive number of days with the daily maximum air temperature ≥33.0℃ during the high−temperature period was established as the high−temperature disaster weather index. （3）The high temperature disaster index of crayfish farming was divided into five grades: mild, light, moderate, heavy and severe levels, and the pure insurance premium rate determined about 4.5%，a historical back−tested loss ratio of 82.08%, and a compensation ratio per 667m² of 3.1%−8.1%. （4）The Qianjaing pilot in 2024 had confirmed that this product was reasonable both in compensating farmers' losses and in the insurance companies' operation, it was an effective tool for stabilizing farming income and promoting the risk management of the crayfish industry.

Key words: Crayfish, Index insurance, High temperature disaster level, Insurance product pricing