Burford Michele A, Johnson Suzanne A, Cook Andrew J, Packer Timothy V, Taylor Bradley M, Townsley E Robert
Australian Rivers Institute, Griffith University, Nathan, Qld 4111, Australia.
Water Res. 2007 Oct;41(18):4105-14. doi: 10.1016/j.watres.2007.05.053. Epub 2007 Jun 3.
This study examined the correlations between watershed and reservoir characteristics, and water quality parameters related to algal blooms in seven subtropical reservoirs. Analysis of the dissimilarity of physico-chemical parameters resulted in separation of the reservoirs into three main groups: four reservoirs with the highest proportion of agriculture and/or urban land use in their watersheds; two reservoirs with a high proportion of forest cover; and one small reservoir with a relatively pristine watershed intermediate between the other two groups. All reservoirs were dominated by cyanobacteria, and at times, had species capable of producing toxins. However, the three reservoirs with the lowest percentage forest cover ( approximately 50%) had the highest frequency and magnitude of toxic species, principally Cylindrospermopsis raciborskii. Analysis of dissimilarity of algal species composition resulted in three reservoir groups similar to that for the physico-chemical parameters, with the exception of the reservoir with the highest percentage urban land use being an outlier. Across all reservoirs, percentage forest cover in the watershed, watershed area and reservoir volume were all significantly correlated with algal cell concentrations and total nitrogen (TN), but not with chlorophyll a concentrations. Total phosphorus (TP) was only correlated with the proportion forest cover in the watershed, suggesting that reservoir volume and depth were of less importance for TP than for algal cell concentrations or TN. These results suggest that watershed pattern and reservoir characteristics, such as water volume and depth, have a measurable effect on the type of algal blooms in reservoirs.
本研究考察了七个亚热带水库的流域和水库特征与藻华相关水质参数之间的相关性。对理化参数差异的分析结果显示，这些水库可分为三大类：四个流域内农业和/或城市土地利用比例最高的水库；两个森林覆盖率高的水库；以及一个小水库，其流域相对原始，处于另外两组之间。所有水库均以蓝藻为主，且有时存在能够产生毒素的物种。然而，森林覆盖率最低（约50%）的三个水库有毒物种的出现频率和数量最高，主要是柱孢鱼腥藻。对藻类物种组成差异的分析得出了与理化参数类似的三个水库组，但城市土地利用比例最高的水库是一个异常值。在所有水库中，流域内的森林覆盖率、流域面积和水库库容均与藻细胞浓度和总氮（TN）显著相关，但与叶绿素a浓度无关。总磷（TP）仅与流域内的森林覆盖率相关，这表明水库库容和深度对TP的重要性低于对藻细胞浓度或TN的重要性。这些结果表明，流域模式和水库特征，如水量和深度，对水库中藻华的类型具有可测量的影响。
