College of Environmental and Chemical Engineering, Xi'an Polytechnic University, Xi'an 710048, China.
Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
Int J Environ Res Public Health. 2023 Feb 25;20(5):4141. doi: 10.3390/ijerph20054141.
Water-scarce cities have fewer surface water (SW) resources available for ecological use, causing landscape water to deteriorate due to water shortage and fail to perform their intended landscape functions. As a result, many cities use reclaimed water (RW) to replenish them. However, this could cause concern among the people, as RW usually has higher nutrient concentrations, which may stimulate algae growth and deteriorate the aesthetic senses of the receiving water bodies. In order to assess the feasibility of using RW for this purpose, this study used Xingqing Lake in Northwest China as insight into the effect of RW replenishment on the visual landscape quality of urban landscape water. Water transparency (measured by SD) is used as an intuitive indicator to reflect the comprehensive influence of suspended solids and algae growth on the water's aesthetic quality. Scenario analyses were carried out after calibrating and validating one-year data in MIKE 3 software with both SD and algae growth calculations, and the results showed that the low concentration of suspended matter in RW could compensate for the decrease in SD due to algal blooms caused by high concentrations of nitrogen and phosphorus, and the effect on SD is especially pronounced under conditions that are not conducive to algal growth, such as good flow conditions and low temperature. In addition, to meet a SD ≥ 70 mm, the total water inflow required can be significantly reduced with the optimal application of RW. It is also indicated that partial or complete utilization of RW to replace SW for replenishing the landscape water could be feasible from the viewpoint of landscape quality, at least for the landscape water investigated in this study. This can provide a method for the improvement to urban water management practices by using RW for replenishment in water-scarce cities.
缺水城市的地表水 (SW) 资源较少，用于生态用途，导致景观水因缺水而恶化，无法发挥其预期的景观功能。因此，许多城市使用再生水 (RW) 来补充。然而，这可能会引起人们的担忧，因为 RW 通常具有更高的营养浓度，这可能会刺激藻类生长，恶化受纳水体的美学感受。为了评估 RW 用于此目的的可行性，本研究以中国西北的兴庆湖为例，研究 RW 补给对城市景观水视觉景观质量的影响。水透明度（用 SD 测量）被用作反映悬浮固体和藻类生长对水的美学质量的综合影响的直观指标。在 MIKE 3 软件中对一年的数据进行校准和验证后，进行了情景分析，该软件同时计算了 SD 和藻类生长，结果表明，RW 中低浓度的悬浮物可以补偿由于氮和磷浓度高而导致的藻类大量繁殖导致的 SD 下降，并且在不利于藻类生长的条件下，例如良好的流动条件和低温下，对 SD 的影响尤其明显。此外，为了达到 SD≥70mm，可以显著减少所需的总进水流量，通过 RW 的最佳应用。这也表明，从景观质量的角度来看，部分或完全利用 RW 替代 SW 来补充景观水是可行的，至少对于本研究中调查的景观水是可行的。这可以为缺水城市利用 RW 进行补水来改善城市水管理实践提供一种方法。
