云南抚仙湖透明度的时空变化及影响因子分析

Spatial-temporal dynamic changes of the water transparency and their influencing factors in Lake Fuxian, Yunnan Province

根据2005年的综合调查资料和1980年以来的常规监测资料,分析了云南高原深水湖泊抚仙湖透明度的空间分布、年际变化及影响因子.2005年6-7月抚仙湖水体透明度范围为0.5-6.2m,平均值为4.6m,透明度分布的总体格局是:南区>北区,湖心区>沿岸区,河口区较低.藻类和悬浮物是影响透明度空间分布的主要因子,随着水体中藻类和悬浮物的增加,透明度下降.近20多年来,抚仙湖透明度呈下降趋势,藻类增加是直接影响因子,水体总氮、总磷的增加促进了藻类的增殖,是重要的间接影响因子.

The spatial distribution, temporal changes of water transparency and their influencing factors in Lake Fuxian, a deep lake in Yunnan Plateau, were analyzed according to the investigations during June-July in 2005 and the regular monitoring data since 1980, The Secchi disk transparency varied from 0.5-6.2m with an average value of 4,6m in Lake Fuxian during June-July in 2005, The spatial distribution pattern of transparency was： north area〈south area, littoral zone〈pelagic zone, and very low in the estuary area. Suspended solid and algae were the main influencing factors on spatial distribution of water transparency which decreased with their increase, In the last 20 more years, water transparency in Lake Fuxian showed decrease trend, and the increase of algae was the main direct influencing factor. The increase of total nitrogen and total phosphorous was the important indirect influencing factors which could lead to algae multiplication.