Abstract: River crab industry is one of the most prominent special aquatic industries in Jiangsu Province. It is extremely important to effectively avoid the main meteorological disasters in crab production and breeding. In this study, based on meteorological data, as well as observations and yield data of river crabs, at the daily scale, we determined the key meteorological factors influencing the growth of river crabs during the process of high-temperature heat damage. The daily high-temperature heat damage index of river crabs was constructed by applying membership model. At the annual scale, the synthesis index of high-temperature heat damage of river crabs was constructed. Furthermore, the relationships between high temperature heat damage index and yield loss of river crab were analyzed, and the high temperature heat damage was divided into five grades following the damage degrees. The interdecadal characteristics of hightemperature heat damage were analyzed. On this basis, the occurrence features of typical high temperature heat damage and yield reduction rates of river crab in 2018 were evaluated quantitatively. The results showed both temporal and spatial variations in the occurrence frequency and intensity of different grades of heat injury for river crab during the period from 1981 to 2018. In terms of the synthesis index, the occurrence frequency of moderate and above heat hazards showed a spatial distribution pattern of “more in the south and less in the north”, appearing an upward trend over time, with the largest increase during the period from 2001 to 2010. The spatial distribution of heat damage intensity showed a feature of “heavy in the south and light in the north”, with an aggravated trend over time. The high-value area was significantly extended from sporadic distribution in southern Jiangsu to the southern Huaihe River basin during 2011 to 2018. According to the daily index, the intensity of different levels of heat damage had little change at the inter-decadal time scale, while the frequency of occurrence had an upward trend with time, having a backward trend of its peak. Generally, indices of high temperature heat damage at different time scales could better reflect the impacts of disaster on the production processes and yields of river crabs from two aspects.

Key words: river crab, membership model, high temperature heat damage index, change characteristic, evaluation, Jiangsu.