肇庆星湖水质现状与变化趋势

在2002年对星湖四个子湖进行采样调查,运用相关加权综合营养状态指数来评价水质营养状态,结果富营养化程度由高到低依次为波海湖、中心湖、青莲湖、仙女湖。与1996～1997年的调查结果比较,波海湖仍处于富营养化状态,中心湖富营养化程度加剧,其富营养化程度超过了青莲湖和仙女湖,由中营养型过渡到了中富营养型。营养盐与叶绿素a的相关分析表明,硝态氮与叶绿素有正相关关系,与磷盐没有明显相关性,说明了硝态氮是星湖初级生产力的主要限制因子之一,而磷的含量充足,对初级生产力没有明显的限制作用。与1996～1997年比较,星湖总氮负荷增加46.5%,总磷负荷下降40.8%,而叶绿素a由6.0mg·m^-3升高到16.9mg·m^-3,说明星湖的富营养化仍在进一步加剧。

Water quality and its change in Xianhu Lake, Guangdong Province

Xianghu Lake is tropical urban lake, lacated in Zhaoqin city of Guangdong Province, and it has five sublakes which connect each other. The water quality for the four sub-lakes was investigated in 2002. The results indicated that the trophic level in the sublake Bohai was the highest, and followed by sublake: Zhongxin. In comparison with the measurement in 1996-1997, Zhongxin sublake, used to be the lowest sulake in trophic level, changed from mesotrophic to meso-eutrophic. The concentration of Chlorophyll-a was significately relayed to the concentration of NO₃^-, but not with the concentration of PO₄^3-, suggested that NO₃^- may be the main limited factor for primary production. In contrast to the data from 1996-1997, the nitrogen loading in Xinghu Lake increased by 46.5%, phosphorus loading decreased by 40.8%, the concentration of Chlorohylla increased from 6.0mg·m^-3 to 16.9 mg·m^-3.