基于SCS和USLE的程海总磷总氮参照状态推断

将流域入湖的氮磷负荷分为点源和非点源两部分,基于SCS模型和USLE模型,分别计算流域入湖的溶解态和颗粒态非点源负荷,根据工业、城镇生活及规模养殖废水排放,计算了流域入湖的点源负荷。通过计算的入湖负荷和现有的湖泊氮磷浓度数据,建立了湖泊氮磷质量守恒模型。根据计算的逐年入湖氮磷负荷和建立的湖泊氮磷质量守恒模型,逆推逐年的湖泊氮磷浓度,确定湖泊氮磷参照状态。应用建立的模型推断程海的TP、TN参照状态分别为0.014 mg/L和0.247 mg/L。构建的湖泊氮磷参照状态推断模型,所需资料少,概念清晰,在资料缺乏的其他湖泊流域具有推广应用价值。

Correlation Analysis between Abundance of Trichodina spp. and Water Quality Parameters

To understand the correlations between the abundance of Trichodina spp. and the water quality parameters, the abundance of Trichodina spp. on the gill of yellow catfish in aquaculture water was investigated. Meanwhile, the temperature and total phosphorus, available phosphorus, total nitrogen, nitrite and ammonia nitro- gen contents of the aquaculture water were measured and determined. The results showed that the abundance of Trichodina spp. on the gill of yellow catfish was negatively correlated with the total phosphorus, available phosphorus and total nitro- gen contents in the aquaculture water, and was positively correlated with the nitrite content in the aquaculture water （P〈0.05）; there were no significant correlations between the abundance of Trichodina spp. and the temperature and ammonia nitrogen content of the aquaculture water （P〉0.05）.