Su Yifan, Gan Lin, Li Yun, Fan Ziwu, Xie Chen, Liu Yang, Liao Yipeng, Ding Rui, Liu Guoqin, Wu Jingxiu, Chen Guangyu, Sun Jianhao, Zhu Wenhan, Ma Jingtian
Nanjing Hydraulic Research Institute, 210029 Nanjing, China.
Key Laboratory of Taihu Basin Water Resources Research and Management of Ministry of Water Resources, 210029 Nanjing, China.
Heliyon. 2022 Sep 21;8(10):e10601. doi: 10.1016/j.heliyon.2022.e10601. eCollection 2022 Oct.
Increasing eutrophication and climate change have led to heavy cyanobacterial blooms in water diversion sources (e.g., lakes, reservoirs), which can potentially cause algae-bearing water to spread to downstream to an urban river network via diversion channels. Defining the extent of cyanobacterial blooms in an urban river network has become a novel concern in urban river management. In this paper, we investigated the physicochemical and algae community characteristics of a small, closed, urban river network, JiangXinZhou (JXZ), in the Lake Taihu basin. We propose a novel indicator, resource use efficiency (RUE), for defining the extent of cyanobacterial blooms in JXZ, whose recreational drinking water comes entirely from outside diversion sources. The results show that the JXZ's aquatic habitat conditions (mean water temperature, total nitrogen concentration, total phosphorus concentration, and nitrogen to phosphorus ratio) are highly suitable for the proliferation of cyanobacterial biomass during the high-water period. The RUE was used for calculation and shows a strong relationship with algae density, which means that it can be used as an index to define the degree of urban river cyanobacterial blooms. The findings indicate that the risk of cyanobacterial bloom is absent when the RUE is less than 46.81; blooms appear in the water bodies when the RUE reaches up to 106.68. This work provides theoretical support for the sustainable use of regional water resources.
日益严重的富营养化和气候变化导致了引水水源（如湖泊、水库）中蓝藻大量繁殖，这可能致使含藻水通过引水渠道扩散至下游的城市河网。确定城市河网中蓝藻大量繁殖的范围已成为城市河流管理中的一个新问题。在本文中，我们调查了太湖流域一个小型封闭城市河网江心洲（JXZ）的理化和藻类群落特征。我们提出了一种新的指标，即资源利用效率（RUE），用于确定JXZ中蓝藻大量繁殖的范围，其休闲饮用水完全来自外部引水水源。结果表明，JXZ的水生栖息地条件（平均水温、总氮浓度、总磷浓度和氮磷比）在高水位期非常适合蓝藻生物量的增殖。利用RUE进行计算，结果表明它与藻类密度有很强的关系，这意味着它可以作为一个指标来定义城市河流蓝藻大量繁殖的程度。研究结果表明，当RUE小于46.81时，不存在蓝藻大量繁殖的风险；当RUE达到106.68时，水体中会出现蓝藻大量繁殖。这项工作为区域水资源的可持续利用提供了理论支持。
