1. The relative importance of water temperature and residence time in predicting cyanobacteria abundance in regulated rivers
- Author
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Taegu Kang, Kyung Hwa Cho, Hyuk Lee, Joon Ha Kim, and YoonKyung Cha
- Subjects
Cyanobacteria ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Population Dynamics ,010501 environmental sciences ,Residence time (fluid dynamics) ,01 natural sciences ,Nutrient ,Rivers ,Abundance (ecology) ,Republic of Korea ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,Trophic level ,biology ,Ecology ,Ecological Modeling ,Temperature ,Water ,Bayes Theorem ,Eutrophication ,biology.organism_classification ,Pollution ,Water temperature ,Weir ,Environmental science ,Bloom ,Environmental Monitoring - Abstract
Despite a growing awareness of the problems associated with cyanobacterial blooms in rivers, and particularly in regulated rivers, the drivers of bloom formation and abundance in rivers are not well understood. We developed a Bayesian hierarchical model to assess the relative importance of predictors of summer cyanobacteria abundance, and to test whether the relative importance of each predictor varies by site, using monitoring data from 16 sites in the four major rivers of South Korea. The results suggested that temperature and residence time, but not nutrient levels, are important predictors of summer cyanobacteria abundance in rivers. Although the two predictors were of similar significance across the sites, the residence time was marginally better in accounting for the variation in cyanobacteria abundance. The model with spatial hierarchy demonstrated that temperature played a consistently significant role at all sites, and showed no effect from site-specific factors. In contrast, the importance of residence time varied significantly from site to site. This variation was shown to depend on the trophic state, indicated by the chlorophyll-a and total phosphorus levels. Our results also suggested that the magnitude of weir inflow is a key factor determining the cyanobacteria abundance under baseline conditions.
- Published
- 2017