太湖流域某养殖池塘水平衡分析和水生态模拟

Water balance analysis and water ecology simulation study of a certain aquaculture pond in Taihu Lake basin

为解决传统池塘养殖产生的环境污染问题,应用水生态模型对养殖池塘水生态环境进行模拟。以太湖流域某养殖池塘为例,通过水量平衡分析得到具体补排水时间序列,输入AQUATOX水生态模型软件进行建模,经过率定验证后进行控制模拟,针对投饵率对水质与养殖品之间的相互影响规律进行探讨。结果表明:基于降雨-水位的补排水识别方法能弥补具体补排水量的测量空白;饵料对研究池塘水质影响较大,在1%~7%的投饵率梯度中,随着投饵率的增加,TP、TN和氨氮质量浓度整体上大幅增加;以养殖品安全质量浓度为界,在1%~7%的投饵率梯度内养殖品产量随氨氮质量浓度的增加呈现先增后减的趋势。该研究建立的水生态系统模型模拟效果较好,综合考虑保持良好的水生态环境与经济成本,该池塘养殖中的建议投饵率为2.5%~3.0%。

Freshwater pond culture had an important position and role in the national economy and even in social development.Baiting was one of the important aspects of the pond culture process,and the rationality of the amount of baiting affected aquatic health and the benign purification of water quality.Traditional pond culture was mostly based on empirical baiting,and its wastewater discharge was prone to eutrophication of farm ponds and water bodies discharged into the waters,which seriously affects the water ecology.The water management of common farm ponds was often characterized by high frequency,fragmentation and arbitrariness,and it was difficult to obtain accurate data on the amount of inflow and outflow by relying entirely on actual measurements.in order to solve the environmental pollution problems caused by traditional pond aquaculture,the water ecological model can be used to simulate the water ecological environment of aquaculture ponds to provide scientific and accurate decision support data.Taking a breeding pond in the Taihu Lake basin as an example,the time series of inflow and outflow was obtained through water balance analysis,and based on this,it was input into the AQUATOX water ecological model for modeling,and conducted control simulations after calibration and verification to explore the mutual influence of baiting rate on water quality and aquaculture products.The phenomenon of excessive feeding in aquaculture pond has a huge impact on the aquatic ecological environment.The results showed that:The total inflow and outflow volumes during the study period were 163853.11 m^(3) and 67635.73 m^(3);Bait has a large influence on the water quality of the study pond,and the TP,TN and ammonia nitrogen mass concentrations increased significantly overall with the increase of baiting rate in the baiting rate gradient from 1%to 7%;taking the safe mass concentration of cultured products as the watershed,the production of cultured products showed a trend of increasing and then decreasing with the increase of ammonia nitrogen mass concentration in the baiting rate gradient from 1%to 7%.The based rainfall-water level inflow-outflow identification method can fill the measurement gap of specific water management;The water ecosystem model established was simulated well,and the recommended baiting rate in this pond culture was 2.5%to 3%considering the maintenance of good water ecosystem and economic cost.