| By using means of mathematical statistics and empirical orthogonal function decomposition (EOF), the interannual variation characteristics of the elements in the Meiyu period of the 72 stations in the Yangtze-Huaihe region from 1960 to 2015 are analyzed. According to the study of the factors and characteristics of drought and flood during the rainy season in the Yangtze River Basin, the effects of the anomalous sea surface temperature are analyzed by using means of singular value decomposition (SVD). Finally, the influence of the main climate anomalies on the environment of open aquaculture in the Yangtze-Huaihe region is studied by using the measured data of Tongwei aquaculture base in Dafeng City, Jiangsu Province.The main conclusions are:(1) It is found that there is no significant trend in the start or end date of Meiyu in the Yangtze-Huaihe region from 1960 to 2015, but the interannual variation increased, the interannual variation period became longer, and the interannual difference of the Meiyu date is larger; the first mode (LV1) is the same type of the region, the second mode (LV2) is the north-south reverse phase, the third mode (LV3)is the middle and north-south reverse type, the fourth mode (LV4) The The average sunshine hours before and after 1985, the overall trend was significantly reduced; the minimum temperature rise trend than the average temperature and the maximum temperature of the temperature rise in the rainy season, (1980) and the maximum temperature (2002); the wind speed is significantly reduced. The correlation between the elements of the Meiyu period in the Yangtze-Huaihe region is good, and the amount of precipitation can reflect the abnormal changes of other factors to a certain extent.(2) During the Meiyu season, the trend of drought and flood in the Yangtze-Huaihe region is more consistent, but there are some differences in the subregion. There is a significant correlation between the change of sea surface temperature and the situation of drought and flood in the Yangtze-Huaihe region: The drought and flood in the northeastern of the Yangtze-Huaihe region are significantly related to El Nino, When the eastern equatorial sea temperature rises and the western Pacific sea temperature decreases, the northeastern region of the Yangtze-Huaihe region is flooded and the western part is drought ,and vice versa; When the equatorial high temperature in the central and eastern Pacific, the North Pacific sea temperature is low, the central region of t the Yangtze-Huaihe region waterlogging.(3) The precipitation and temperature of Meiyu season in the Yangtze-Huaihe region are negatively correlated with the pH value of the aquaculture environment,When the precipitation is too high, the temperature is high, the aquaculture environment pH is low, acidic,easy to make fish and shrimp floating head disease;When the precipitation is too small, the temperature is low, the aquaculture environment pH high, alkaline enhancement, prone to rotten gill disease. The correlation between ammonia nitrogen and wind speed in aquaculture water environment is good. During the Meiyu season,when the wind is strong,the aquatic environment of ammonia nitrogen value is high,easy to send crab rotten gills, black gill disease.(3) The anomalous SST of the Pacific Ocean in the early period has a certain indication to the anomalies of the climatic resources in the Yangtze-Huaihe region,thus affecting the open aquaculture industry. This effect is mainly manifested as:When the eastern Pacific and the western Pacific winter's SST is high,the northern and eastern parts of the Yangtze-Huaihe region's aquaculture environment prone to rotten gill disease and crab rotten gills, black gill disease in the later spring; When the SST of the Middle East and Northwest Pacific continues to be high in winter and spring, the head of the the Yangtze-Huaihe region is prone to floating head disease in summer. |
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