珠江河口地区农田水体N、P污染研究

以张松村和万顷沙十五涌的农田水渠为研究对象,根据水系分布情况设置采样点,分析N﹑P在渠系中的时空变化规律.结果表明,农田水渠水体N、P平均浓度高于附近河涌及珠江河道.两个研究区中TN、NH4+-N浓度沿着排水水流方向总体上有逐渐减小的趋势,而NO3--N浓度逐渐增大.万顷沙十五涌农田水渠TP沿着排水水流方向逐渐减小,而张松村的变化无明显规律. Spearman相关分析结果显示,张松村农田水渠TN与NH4+-N、TP、CODcr呈显著性正相关;NH4+-N与NO3--N呈负相关;万顷沙十五涌农田水渠TN与NH4+-N、TP、NO3--N和CODcr呈显著性正相关.该研究可为珠江河口地区水环境保护和农业面源污染治理提供参考依据.

Study on nitrogen and phosphorus in farmland water bodies of the Pearl River estuary

A case study of drains in Zhangsong Village watershed and in No.15 Chung of Wanqingsha was carried out.The spatial-temporal dynamics of nitrogen and phosphorous concentrations in farmland ditch systems were investigated.Results showed that the average concentrations of nitrogen and phosphorous in farmland drainage water were higher than those in the nearby streams and the Pearl River.Along with the downstream of drains,TN and NH4+-N concentrations decreased,however,NO3——N concentrations increased gradually.TP concentrations in No.15 Chung of Wanqingsha decreased alone with the downstream of drains,but no significant change occurred in drains of Zhangsong village.Spearman correlation analysis showed that the relationships between TN and NH4+-N、TP、CODcr were positively correlated respectively in zhangsong village drains,but NH4+-N and NO3——N was negatively correlated.The relationships between TN and NH4+-N,NO3——N,TP and CODcr were significantly positively correlated in No.15 Chung of Wanqingsha drain.The results could be useful for pollution control of non-point sources in Pearl River estuary.