蠡湖水体悬浮物的时空变化及其影响因素

根据2012~2013年的现场调查资料和历史监测资料,分析了浅水湖泊蠡湖总悬浮物(TSS)的时空分布特征、组成、变化规律,并探讨了水体悬浮物的影响因素及其与氮、磷的关系.结果表明, ρ(TSS)的年内变化范围在1.00~78.00mg/L之间,平均值为17.35mg/L,空间上呈现东蠡湖大于西蠡湖,沿岸高于湖心区的分布趋势;季节变化表现为秋季>夏季>春季>冬季,且冬季显著低于其他季节;全湖水体中ρ(OSS)和ρ(ISS)所占ρ(TSS)的比例相当,分别为51.52%和48.48%,但组成比例空间差异较大,东蠡湖ρ(OSS)比例较大,而西蠡湖ρ(ISS)的比例较大.线性拟合表明, ρ(TSS)与ρ(PN)、ρ(TN)、ρ(PP)、ρ(TP)均具呈显著正相关(P<0.01).浮游藻类增殖、水生植物的残体以及底泥的再悬浮是影响水体ρ(TSS)的主要因素.

Spatial-temporal dynamic changes of the water suspended matter and its influencing factors in Lihu Lake

The spatial-temporal distribution characteristics, composition and change rule of ρ(TSS) in Lihu Lake, a shallow lake, were analyzed by field survey data and historical monitoring data in 2012~2013. The key impacting factors of ρ(TSS) and relationship between it and nitrogen, phosphorus were discussed. Results showed that the annual ρ(TSS) was 1.00~78.00mg/L, with the mean value of 17.35mg/L. ρ(TSS) in east Lihu Lake and coastal areas was higher than that in west Lihu Lake and lake center, respectively. The seasonal characteristics of ρ(TSS) was autumn>summer> spring>winter, and ρ(TSS) in winter was significantly lower than the other seasons. ρ(OSS) and ρ(ISS) almost took the same proportion of ρ(TSS) in the whole lake, with the value of 51.52% and 48.48%, respectively. While significant spatial heterogeneity existed in the composition ratio. OSS was the main composition of east Lihu Lake, but the suspended matter of west Lihu Lake mainly existed in inorganic component. Results of multivariate regression analysis showed that ρ(TSS) was significant positive correlated with ρ(PN), ρ(TN), ρ(PP), and ρ(TP) (P<0.01). Planktonic algae proliferation, residues of aquatic plants and sediment resuspension were the main factors influencing ρ(TSS) in water.