Abstract:

As one of the most important factors affecting aquaculture activities, a numerical model for water temperature simulation has been developed to accurately describe the pattern of temperature variation in shallow water bodies. The model was based on the one-dimensional heat diffusion equation, which considered factors such as water surface heat exchange, shortwave radiation absorption within the water body, and thermal convection. The boundary conditions were based on the assumption of surface heat balance and no heat exchange at water body bottom. Meteorological factors such as temperature, relative humidity, wind speed, cloud cover and solar radiation were used as input parameters. The simulation model was solved using explicit integration scheme. A simulation experiment was conducted from June 21 to 29, 2023, after calibrating the model parameters with observed water temperature in the fish pond of the Shanghai Jufu Aquaculture Professional Cooperative in Qingpu district, Shanghai. This model demonstrated strong capacity for water temperature simulation in shallow water ponds by addressing the trends and magnitude of water temperature variations at all levels. Through comparison with observation data, the simulated water temperatures were significantly correlated with the observed values, with correlation coefficients exceeding 0.8 at all levels and root mean square errors 0.8℃ to 1.1℃. The model is capable of generating water temperature simulation outputs for specified periods and depths, tailored to user requirements. Such outputs hold promising prospects for broader application, offering detailed guidance that can significantly enhance aquaculture activities.

Key words: Shallow water fish ponds, Vertical water temperature, Numerical simulation model