Vertical Variation Pattern and Cause Analysis of Water Temperature in Fish Ponds on Sunny Days in Summer
To reveal the impact of meteorological factors on the vertical gradient of water temperature,daily and hourly meteorological observation data from the Honghu National Meteorological Station in the summer of 2022 was used,as well as minute by minute water temperature observation data from different depths at the Honghu Aquatic Base,mathematical statistics and correlation analysis were used to analyze the vertical variation of water temperature in pond aquaculture on sunny days in summer.The results showed that:(1)on clear days in summer,the single peak daily variation characteristics of water temperature in each layer were obvious,with the minimum value appearing before sunrise,the highest value of surface water temperature appearing around 16:00.The deeper the water layer,the later the highest and lowest values appear.The changes in water temperature in the upper and lower layers had a certain lag.(2)Light had a significant impact on water temperature,and there was a significant positive correlation between the two factors.The correlation coefficient reached its maximum at a depth of 60 cm;the average illumination at different levels was negatively correlated with the vertical gradient of water temperature,while the illumination gradient at different levels was significantly positively correlated with the vertical gradient of water temperature.(3)There was a significant negative correlation between the vertical gradient of water temperature and wind speed.The higher the wind speed,the smaller the vertical gradient of water temperature.When the wind speed ranges from 3 to 4,and the vertical gradient of water temperature was small,it was advisable to temporarily postpone or reduce the use of oxygen generators in a timely manner.(4)There was a significant positive correlation between the vertical gradient of water temperature and water vapor pressure.The higher the water vapor pressure,the greater the vertical gradient of water temperature.In hot and humid weather,it was necessary to strengthen the patrol of the pond and timely start the aerator.The paper revealed the mechanism of the influence of meteorological factors on the vertical gradient of water temperature,and provided technical support for healthy aquaculture.
summersunny daysvertical gradient of water temperatureilluminancewindvapor pressure