北方寒区水库氮、磷营养盐的时空变异特征

SPATIAL AND TEMPORAL DISTRIBUTION CHARACTERISTICS OF NITROGEN AND PHOSPHORUS IN RESERVOIRS IN NORTHERN COLD AREA

为揭示北方寒区水库氮、磷营养盐浓度时空分布特征和变化规律,有代表性地选择了锡林郭勒盟多伦县大河口水库18个水质监测点进行采样检测,并以2014年5,7,10,12月水库各采样点水质参数指标为基础,应用ArcGIS9.2统计模块分析不同期水库氮、磷营养盐浓度的时空变异性。结果表明:大河口水库NH_4^+-N、NO_3^--N、TN和TP等主要营养盐因子既有明显的季节变化特征,也存在显著的空间分布差异。水库TN、TP浓度由高到低呈现出秋、夏、春、冬季节性变异特征,且冬季与春、夏、秋3季差异显著;秋、冬季NH_4^+-N浓度明显高于春、夏季;夏季NO_3^--N浓度明显高于其他季节。在空间分布上,水库NH_4^+-N、NO_3^-N、TN、TP浓度分布呈现春季由库中心水域向周边逐渐降低,其他季节由滦河、吐力根河入库水域向出口处逐渐降低的显著空间变异特征。大河口水库氮、磷营养盐浓度时空变异特征受季节、水动力学特征、冰封和冻融等自然因素和人类生产、生活排污的人为影响均较为显著。

In order to reveal spatial and temporal distribution and change rule of nitrogen and phosphorus nutrients in reservoirs in China＇s northern cold area,18 water quality monitoring points in Dahekou Reservoir,located in Duolun County in Xilin Gol League were selected typically,and the water quality parameters of each point was monitored in May,July,October and December of 2014. The spatial and temporal distribution of nitrogen and phosphorus were analyzed in different seasons of reservoirs by using statistical module of Arc GIS 9. 2. The results showed that the main nutrient factors such as ammonia nitrogen,nitrate nitrogen,total nitrogen and total phosphorus in Dahekou Reservoir had obvious seasonal variation and also had significant differences in spatial distribution. The concentration of total nitrogen and total phosphorus appeared descending trend during autumn,summer,spring and winter in the whole reservoir area,and there were significant difference between winter and other there seasons; the concentration of ammonia nitrogen in autumn and winter was significantly higher than that in spring and summer; the concentration of nitrate nitrogen in summer was significantly higher than other seasons. In the spatial distribution,the concentration of ammonia nitrogen,nitrate nitrogen,total nitrogen and total phosphorus presented a decreasing trend from the center to the surrounding area in the Dahekou Reservoir during the spring,while the same trend was along the flow direction from the entrance of Luan River and Tulai River to the exit during the other seasons. The spatial and temporal distribution of nitrogen and phosphorus nutrients in Dahekou Reservoir were influenced significantly by natural environmental factors such as seasonal features,hydrodynamic characteristics,ice-freezing and freezing-thawing,and manmade factors of human production and life sewage.