滇池宝象河流域水体氮素特征及影响因素

非点源流失的氮是造成水体污染的主要因素之一.通过对滇池宝象河6个点位沟渠水和河道水体氮素的动态监测,研究了流域水体氮污染特征和影响因素.结果表明,农田沟渠水总氮平均浓度高于相应河道水总氮浓度,沟渠水总氮平均浓度范围为3.86～22.86 mg/L,河道水总氮浓度3.14～6.63 mg/L,总体趋势是从上游到下游水体氮素浓度逐渐升高、并且沟渠水体和河道水体氮素随时间变化呈现同样的趋势.农田沟渠水与河道水体总氮之间、农田沟渠水总氮与沟渠周边表层土壤全氮及沟渠沉积物全氮均呈显著相关性.

Characteristics and Influence Factors of Water Body Nitrogen in Baoxiang River Watershed of Dianchi Lake Area

Nitrogen loss in non-point source is the main factor causing water pollution. By dynamic monito-ring of water body nitrogen in six ditches and stream channels in Baoxiang River watershed , the characteris-tics and influence factors of nitrogen pollution in water body were studied. Results showed that in different locations and different times,the nitrogen concentration of ditch water on farmland is greatly different from that in channel water. The average concentration of total nitrogen (TN) in ditch water is higher than that in the corresponding channel water. The average TN concentration in ditch water ranged from 3. 86 to 22. 86 mg/ L and the TN concentration in channel water,from 3.14 to 6.63 mg/ L. The overall trend is that the ni-trogen concentration of water body gradually increased from upstream to downstream. Nitrogen in ditch water on farmland and in channel water showed the same trend over time. TN between ditch water and channel water and TN between ditch water on farmland and the surface soils surrounding ditches and stream sediment are significantly correlated