摘要
采用Mann-Kendall非参数统计检测法对长荡湖长序列水质参数进行分析,再利用模糊综合评价法评价历年水质状况,同时找出导致水质变化的主要影响因子。趋势分析表明:长荡湖p H、EC、DO、BOD、COD、TP、CODMn、SS呈上升趋势,SD、NH3-N、TN、粪大肠杆菌群数和石油类呈下降趋势,其中SS近年急剧上升,SD下降,耗氧类参数上升明显,说明长荡湖近8年水质总体呈下降趋势。突变分析表明:SS有1个突变点位于极显著信度线(α=0.01)之外,SS、BOD、COD还各有1个突变点位于显著信度线(α=0.05)与极显著信度线之间,其余突变点均位于显著信度线之间。对突变次数及时间进行分析,结果表明:COD突变最复杂,SD和石油类变化趋势最简单,突变主要集中在2006、2008和2012年。模糊综合评价结果显示长荡湖水质2005—2009年变化不大,2009年后水质由Ⅲ类变为Ⅳ类,其主要影响因子为BOD、COD、TN和CODMn。
A long series of water quality parameters of Changdang Lake was analyzed using the Mann -Kendall method, which is a non-parameter statistical test method .The water quality of the lake was evaluated with the fuzzy comprehensive evaluation method , and the main factors influencing the water quality were determined .Trend analysis shows that pH , EC, DO, BOD, COD, TP, CODMn , and SS had an increasing trend , while SD, NH3-N, TN, fecal coliform , and petroleum had a decreasing trend in the lake .Over the past eight years , SS has increased sharply , SD has decreased , and oxygen consumption parameters have increased significantly , indicating that the water quality of Changdang Lake has deteriorated .SS had an abrupt change point exceeding the extremely significant reliability line （α=0.01）;BOD, COD, and SS had abrupt change points between the significant reliability line （α=0.05） and the extremely significant reliability line （α=0.01）;and the other abrupt change points were between two significant reliability lines .Analysis of the abrupt change frequency and time shows that abrupt changes mainly occurred in years 2006, 2008, and 2012, and the change of COD was most complex , while the change trends of SD and petroleum were easiest to follow .Fuzzy comprehensive evaluation shows that the water quality of Changdang Lake changed insignificantly during the period from 2005 to 2009.Since the year 2009, with the effects of BOD , COD, TN, and CODMn , the water quality of Changdang Lake has decreased from class III to class IV .
出处
《水资源保护》
CAS
2014年第6期48-53,共6页
Water Resources Protection
