乌梁素海表层沉积物营养盐的分布特征及环境意义

采用现场采样及室内测试方法,对乌梁素海表层沉积物营养元素（TN、NH4＋-N、NO3--N、TP和TOC）的分布特征进行了分析,系统研究了沉积物碳-氮-磷两两之间的相互耦合关系及其环境意义,并对乌梁素海沉积物的有机污染状况进行了评价。结果表明,乌梁素海表层沉积物TOC/TN比平均值为12.70,反映出有机质来源可能是湖泊水生生物和陆源输入,其中外源输入略占主导;TOC/TP比值高于TOC/TN,沉积物中的有机质主导着TOC/TP比值的变化趋势;TN/TP比值的分布表现出与TOC/TP比值相似的变化特征。有机污染评价结果显示,全湖的有机指数均值为0.42,处于尚清洁状态,w（ON）的均值为0.17%,属于有机氮污染状态。

Distribution Analysis of Nutrient Salt in the Sediment of Lake Wulangsuhai with Respect to Its Effects on the Environment

In order to get better understanding to the nutrient salt environmental effects,the distribution and interaction of nutrient elements（TN,NH4＋-N,NO3--N,TP and TOC）were analyzed,which were sampled from the sediment of Lake Wuliangsuhai.The results showed that the average ratio of TOC to TN concentration was 12.70,meaning the organic matter in the sediment could be mainly contributed by the aquatic biota within the lake and transported into the lake from the surroundings.The latter source might contribute a little bit more.The ratio of TOC to TP was greater than that of TOC to TN indicated that the organic matter with the sediment might control the ratio of TOC to TP.However,the ratio of TN to TP had the similar change pattern compared with the ratio of TOC to TP.The results of organic contamination as-sessment illustrated that the average organic index was 0.42 and w（ON）was 0.17%,meaning that the lake water was clean but contaminated by organic N.