渭河陕西段沉积物中总磷、总氮时空分布特征及其影响因素研究

Study on the temporal-spatial distribution characteristics and influencing factors of TP and TN in river sediments for the Weihe River of Shaanxi Province

为探究沉积物中总磷、总氮的时空分布特征及其影响因素,以渭河陕西段5个研究点为例,分别于2013年夏季(6月)和冬季(12月)进行两次采样,通过野外实验对水温、p H、电导率、溶解氧、流速等环境因子的测定,结合室内实验对沉积物中总磷、总氮含量的测定和粒度分析,研究沉积物中总磷、总氮的时空分布特征,以及各环境因子与其相关性.结果表明,大多数研究点沉积物中总磷、总氮含量在垂向上呈现先减小后增大再减小的趋势;在季节上呈现夏季含量高于冬季含量的趋势,其中各研究点夏季沉积物中总磷含量平均值为15.79 g·kg-1,总氮含量平均值为5.50 g·kg-1,而冬季沉积物中总磷含量平均值为5.91 g·kg-1,总氮含量平均值为2.46 g·kg-1;通过沉积物氮、磷元素含量与各环境因子的相关性分析,发现影响沉积物中总磷、总氮含量的环境因子主要有温度、p H、电导率和溶解氧.

To analyze the vertical and seasonal distribution of TP( total phosphorus) and TN( total nitrogen) in Weihe River sediments and to determine the impact of environmental factors on the content of TP and TN in sediments,both laboratory experiments( determination of TP,TN in river sediments and grain size distribution),and field measurements( determination of water temperature,p H,electrical conductivity,dissolved oxygen and flow velocity)were conducted in five sites along the Weihe River in both summer and winter of 2013. The results showed that the vertical distribution of TP and TN in sediments of most sites shows an oscillating relationship with depth. The average contents of TP and TN in river sediments were 15. 79 g·kg- 1and 5. 91g·kg- 1in summer and 5. 50 g·kg- 1and 2. 46 g·kg- 1in winter,respectively. Environmental factors such as water temperature,p H,electrical conductivity and dissolved oxygen had significant impacts on the content of TP and TN in river sediments.