CAJ | 학술논문

为评估长湖水体富营养化程度,20122013年分4个季度对全湖区20个采样点的物理、化学和生物要素进行监测,在评价水质现状的基础上采用综合营养状况指数法和浮游植物细胞丰度指数法综合评价水体营养状况,并应用典型相关分析( CCA)方法揭示水体富营养化状况与湖泊理化要素之间的典型相关性.结果显示：4个季节长湖全湖区的水质均处于地表水IV类~劣V类水标准；综合营养状态指数值在49.54~82.55之间,浮游植物细胞丰度在2.88×106~61.73×106 cells/L之间,均显示其处于富营养化状态；长湖富营养化状况的分布呈现一定的时空差异性；CCA分析显示,长湖理化要素变量可解释68.6%的水体富营养化状况变量的变异,影响其富营养化状况的主要理化因素有水体总磷、总氮、溶解氧、亚硝态氮、硝态氮浓度,水深和沉积物总磷、总氮含量.长湖水体富营养化主要是由于外源的磷污染,其次是氮污染,富营养化最严重的夏、秋季浮游植物的生长主要受氮营养限制,而冬、春季则部分受磷营养限制,部分属于过渡类型.因此,建议大力削减围网/围栏养殖量,同时考虑结合水生植物栽种等生态工程建设措施以降低长湖水体发生严重富营养化的风险,并进一步改善长湖的水质现状.
위평고장호수체부영양화정도,20122013년분4개계도대전호구20개채양점적물리、화학화생물요소진행감측,재평개수질현상적기출상채용종합영양상황지수법화부유식물세포봉도지수법종합평개수체영양상황,병응용전형상관분석( CCA)방법게시수체부영양화상황여호박이화요소지간적전형상관성.결과현시：4개계절장호전호구적수질균처우지표수IV류~렬V류수표준；종합영양상태지수치재49.54~82.55지간,부유식물세포봉도재2.88×106~61.73×106 cells/L지간,균현시기처우부영양화상태；장호부영양화상황적분포정현일정적시공차이성；CCA분석현시,장호이화요소변량가해석68.6%적수체부영양화상황변량적변이,영향기부영양화상황적주요이화인소유수체총린、총담、용해양、아초태담、초태담농도,수심화침적물총린、총담함량.장호수체부영양화주요시유우외원적린오염,기차시담오염,부영양화최엄중적하、추계부유식물적생장주요수담영양한제,이동、춘계칙부분수린영양한제,부분속우과도류형.인차,건의대력삭감위망/위란양식량,동시고필결합수생식물재충등생태공정건설조시이강저장호수체발생엄중부영양화적풍험,병진일보개선장호적수질현상.
In order to assess the water eutrophication status of Lake Changhu, 20 sampling sites with physical, chemical and bio-logical elements of lake were monitored seasonally during 2012 2013. On the basis of evaluated water quality by single-factor wa-ter quality assessment method, two other methods( phytoplankton cell abundance index method and comprehensive trophic level in-dex( TLI) method) were chosen to assess water eutrophication status of Lake Changhu. Then canonical correlation analysis( CCA) was used to demonstrate the canonical relationships between variables of“water eutrophication status” and variables of“physical/chemical elements of lake”. The results indicated that water quality of Lake Changhu in four seasons conformed to the standard of type IV to bad V surface waters. TLI values ranged from 49. 54 to 82. 55, and phytoplankton cell density varied from 2. 88 × 106 cells/L to 61. 73 × 106 cells/L, both of which exhibited the state of eutrophication of Lake Changhu. The water eutrophication of the lake was characterized by significant spatial-temporal variations. The CCA revealed that variables of“physical/chemical indices of lake” could explain 68. 6% of the variations of the variables of“water eutrophication status”, and the main factors affecting eu-trophication of Lake Changhu were total phosphorus, total nitrogen, nitrite-nitrogen and nitrate-nitrogen of water, total phosphorus and total nitrogen of sediment, dissolved oxygen, water depth. Water eutrophication in Lake Changhu was mainly from the pollution of external phosphorus, followed by external nitrogen. In summer and autumn, eutrophication was the worst, and the growth of phytoplankton was mainly influenced by nitrogen limitation. However, in winter and spring, eutrophication could be limited by phosphorus and transitional type. Therefore, we suggest that slashing enclosure culture in the lake, together with transplanting aquatic plants and other measures of ecological engineering, should be carried out with great care in order to reduce the risk of se-vere water eutrophication and to improve water quality in Lake Changhu in the future.