湖泊营养物参照状态建立方法研究

建立生态分区内各类型湖泊营养物的参照状态是营养物基准制定过程中最为核心的内容之一。在系统分析和评价国外确定湖泊营养物参照状态的若干种方法，包括参照湖泊法、湖泊群体分布法、三分法、回归分析等几种统计学方法以及模型推断和古湖沼学重建方法后，文章根据总磷（total phosphorus，TP）、总氮（total nitrogen，TN）、叶绿素a（chlorophyll a,Chl-a）和塞氏透明度（Secci depth）等四项指标的历史监测数据，应用若干统计学方法建立了巢湖的营养物基准参照状态。通过互相之间的比较分析以及长江中下游湖区古湖沼学重建数据的验证，推荐采用湖泊群体分布法5％点位对应的值作为巢湖营养物基准的参照状态。因此，巢湖营养物参照状态阈值范围为总磷0．023～0．27mg·L^-1，总氮O．62～0．63mg·L^-1，叶绿素aO．65～0．67mg·m^-1，塞氏透明度0．65-0．72m。

Study on establishing lake reference condition for nutrient

Lake nutrient reference condition Establishment in an ecoregion is a critical part in nutrient criteria development. Several methods of reference condition establishment have been reviewed as statistical methods, including reference lake approach, lake population distribution approach, trisection approach, regression approach, and model extrapolation and paleolirrmologieal recon-struction. In this paper, based on the historical monitoring data of total phosphorus, total nitrogen, chlorophyll a and Secei depth, statistical method was applied to establish the nutrient reference condition of Chaohu Lake. Through comparative analysis and the validation of paleolimnological reconstruction data about the middle and lower reaches of Changjiang River, 5th percentile of lake population distribution was recommended as reference conditions. Thus, the threshold rang of Chaohu Lake showed that total phos-phoras is 0.023～0.27 mg·L~(-1), total nitrogen is 0.62～0.63 mg·L~(-1),chlorophyll a is 0.65～0.67 mg·m~(-3), Secci depth is 0.65～0.72 m.