盱眙龙虾池塘夏季水温与溶解氧变化特征及预报模型研究

Changing Characteristics and Prediction Model of Water Temperature and Dissolved Oxygen in Xuyi Lobster Pond in Summer

为了进一步提高江苏省夏季虾塘管理水平,减少高温灾害对龙虾产量造成的损失,利用盱眙县龙虾池塘2014年夏季水体溶解氧、p H、不同层水温逐时观测资料以及对应台站气象数据,对溶解氧、p H、水温的小时变化、日变化变化特征进行了分析,并建立了基于BP神经网络的逐层水温及溶解氧预报模型。结果表明:夏季较深层的水温均高于气温,10 cm水温的小时变化幅度最剧烈。日最高水温出现的时间依次为:10 cm>30 cm>60 cm>100 cm。气温与水温波动性较为一致,溶解氧的波动与气温呈负相关,p H波动较小。与空气温度相比,不同层水温波动幅度较小,具有一定的滞后效应。相关性分析表明,不同层最高水温最大值与当日最高气温、前1、2、3、4日最高气温具有较好的关联性,其相关系数达到0.8以上,日平均溶解氧含量与当日最高气温、前1日最高气温、100 cm最高水温呈显著的负相关性。日平均溶解氧含量与不同深度最高水温的实测值与模拟值决定系数均达到0.98以上,相对误差不超过1%,具有较高的模拟精度。本研究构建的盱眙龙虾池塘水温、溶解氧预报模型可为龙虾的养殖和气象灾害防御决策提供理论依据。

In order to improve the daily management of lobster pond in Jiangsu Province and reduce lobster losses caused by the high temperature disasters, using hourly observational data of dissolved oxygen, pH, water temperature of different layers and the corresponding meteorological station data of Xuyi lobster pond in summer in 2014, the authors analyzed hourly chango and daily variation characteristics of dissolved oxygen, pH and water temperature. Based on BP neural network, prediction model of water temperature of different layers and dissolved oxygen was built. The results showed that water temperature of the deeper layers were higher than air temperature in summer and hourly variation amplitude of 10 em water temperature was mostdramatic. The highest water temperature of 10 cm appeared first, followed by that of 30 cm, 60 cm and 100 cm. The fluctuations of air temperature and water temperature were consistent. The fluctuation of dissolved oxygen was negatively correlated with temperature, and pH was relatively stable. Compared with air temperature, water temperature of different layers fluctuated in small amplitude with a certain hysteresis effect. Correlation analysis showed that the maximum water temperature of different layers was correlated with the maximum air temperature and the maximum temperature in recent 4 days and the correlation coefficient was above 0.8. Average daily dissolved oxygen was negatively correlated with the maximum temperature of that day and the day before, and the maximum water temperature of 100 cm. Determination coefficient of measured and simulated values was above 0.98 and the relative error was less than 1%, indicating that the prediction model had high simulation accuracy. Prediction model constructed in this study about the water temperature and dissolved oxygen in Xuyi lobster pond can provide a theoretical basis for lobster fanning and meteorological disaster prevention.