Temporal and spatial distribution of different species of nitrogen in Lake Wuliangsuhai,Inner Mongolia

Abstract

为揭示不同形态氮在乌梁素海空间分布特征及变化规律,运用ArcGIS统计模块分析了2006-2007年乌梁素海不同形态氮浓度的时空变异.研究表明:乌梁素海水体中各监测点总氮浓度夏、冬季高,秋季低,季节性差异较为明显;秋、冬季氨氮平均浓度明显高于夏季;不同季节亚硝态氮平均浓度明显高于硝态氮.在空间分布上,乌梁素海不同形态氮浓度分布呈现出由北向南逐渐降低的趋势.总之,乌梁素海氮素污染问题已十分严重,主要污染源为河套灌区农田排水、沿总干渠区域的工业废水和生活污水,随水体的流动氮污染减少,但某些区域因芦苇、水草密集而使不同形态氮有不同程度的增减.;The temporal and spatial variation characteristics of nitrogen forms are very important for environmental pollution controlof lake. Concentrations of different nitrogen forms were studied using the geostatistical analysis module of ArcGIS in LakeWuliangsuhai. The results indicate that average concentrations of total nitrogen were higher in summer and winter than autumn inseasonal time series, the average concentrations of ammonia nitrogen were lower in summer than autumn and winter, and the averageconcentration of nitrite nitrogen was higher than nitrate nitrogen in different seasons. In space, concentration distribution of differentforms ofnitrogen showed gradually decreasing from north to south. In a word, nitrogen pollution is very serious in LakeWuliangsuhai. The main pollutions were sourced from farm field drainage of the Hetao irrigated areas, industrial waste water anddomestic sewage close to main irrigation canal, which caused different forms of nitrogen contents decreases with the discharge of flowingwater. However, in the region of density reed and aquatic, the contents of nitrogen forms will change with increase or decrease.