嘉陵江营养盐分布特征及对三峡水库的影响

对嘉陵江不同断面营养盐分布进行了研究。结果表明:TN为1.11￣4.18 mg/L,年均值2.16 mg/L;TP为0.03￣0.67 mg/L,年均值0.14 mg/L。不同形态N、P营养盐浓度存在季节性差异,但变化规律不明显。NO3-N是无机氮的主要存在形式,占无机氮的80%￣90%,三态无机N处于较稳定的热力学平衡状态中;流量与TN、TP年输出量呈极显著的线性正相关,相关系数分别为0.997 6**(n=12)、0.996 3**(n=12),说明水体氮、磷主要来自于面源污染。对嘉陵江全年营养盐输出作了初步估算,对比三峡库区城市污水口营养盐排放量,表明嘉陵江全年TN、TP通量分别达到三峡库区67个主要城市污水口排放量的33.2、27.9倍。

Distribution Characters of Nutrient in Jialing River and its Impact on the Three Gorges Reservoir

Nutrient contents in water of Jialing River were investigated.Result showed that the concentration of total nitrogen ranged from 1.11 to 4.18 mg/L with mean concentration of 2.16 mg/L.Total phosphorus ranged from 0.03 to 0.67 mg/L with mean concentration of 0.14mg/L.Contents of the main forms of nitrogen and phosphorus varied seasonally.The main form of inorganic nitrogen in Jialing River was NO3-N,which occupying 80 %～90 % of the total inorganic N.Three forms of inorganic N was in stable thermodynamic equilibrium.There was significant positive correlation between water discharge and total nitrogen fluxes,total phosphorus fluxes.Their correlation coefficient were R2=0.997 6**(n=12)and R2=0.996 3**(n=12),respectively,which indicating that N and P in water mainly came from non-point source pollution.Total nitrogen and total phosphorus load would be 381156 and 52369 tons per year,which were 33.2 and 27.9 times of the 67 main sewage limbers in the Three Gorges areas.