CAJ | 학술논문

在前人工作的基础上,利用门限极值的广义Pareto分布理论和超出阈值峰(Peak Over Threshold,POT)方法,提出了一种确定湖泊参照状态浓度的新方法.该方法不仅能够给出更为精确的置信区间,而且克服了广义极值分布理论取用数据浪费等缺陷.将该方法应用到太湖的水质基准参照状态中,通过POT方法对太湖8个站点1995~2006年总氮(TN),总磷(TP)和叶绿素a(Chl-a)的数据进行预处理,分别以-1.0mg/L,-0.05mg/L与-4μg/L作为它们观测值相反数的门限值,结果表明观测值的相反数符合广义Pareto分布,验证了方法的可行性.推荐采用25%分位点的值作为太湖总氮,总磷和叶绿素a的参照状态,即太湖的参照状态是：总氮0.66mg/L；总磷0.023mg/L；叶绿素a为1.27μg/L.最后分别得出了它们各自的95%置信区间,而且其精度明显高于广义极值分布理论结果.
재전인공작적기출상,이용문한겁치적엄의Pareto분포이론화초출역치봉(Peak Over Threshold,POT)방법,제출료일충학정호박삼조상태농도적신방법.해방법불부능구급출경위정학적치신구간,이차극복료엄의겁치분포이론취용수거낭비등결함.장해방법응용도태호적수질기준삼조상태중,통과POT방법대태호8개참점1995~2006년총담(TN),총린(TP)화협록소a(Chl-a)적수거진행예처리,분별이-1.0mg/L,-0.05mg/L여-4μg/L작위타문관측치상반수적문한치,결과표명관측치적상반수부합엄의Pareto분포,험증료방법적가행성.추천채용25%분위점적치작위태호총담,총린화협록소a적삼조상태,즉태호적삼조상태시：총담0.66mg/L；총린0.023mg/L；협록소a위1.27μg/L.최후분별득출료타문각자적95%치신구간,이차기정도명현고우엄의겁치분포이론결과.
A new method was established to calculate the lake nutrient reference condition based on the extreme threshold theory combined with the Peak Over Threshold. The new method not only revealed statistical inferences, but also overcame the weakness such as wasted observational data in generalized extreme value (GEV) theory. More accurate confidence intervals for parameters and substance concentrations could be obtained using this new method. The method was used to estimate the reference conditions of Taihu Lake. The observed data for total nitrogen (TN), total phosphorus (TP) and chlorophylla (Chl-a) at eight sites located in Taihu Lake during 1995~2006 were pre-treated by the Peak Over Threshold. The results revealed that negative values of TN, TP, and Chl-a, which the threshold values are ?1.0mg/L,?0.05mg/L, and?4μg/L, fitted the generally Pareto model well. It was recommended to use 25th percentile as reference conditions. Thus, the values of the reference conditions for TN, TP and Chl-a were 0.66mg/L, 0.023mg/L and 1.27μg/L, respectively. The 95%confidence intervals were also obtained, more accurately than using generally extreme theory.