Options for the remediation of Windermere: PROTECH modelling of the effects of different management scenarios
Options for the remediation of Windermere: PROTECH modelling of the effects of different management scenarios
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温德米尔修复方案：不同管理方案影响的 PROTECH 建模
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
J. Elliott
中科院分区：
文献类型：
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作者：
S. Maberly;J. Elliott
1.本报告的目的是建立减少营养负荷的影响，从两个污水处理厂（WwTW）在安布莱赛德和塔伍德的数量和类型的浮游植物在温德米尔的两个盆地。第二个目标是评估浮游动物减少放牧压力对浮游植物数量的可能影响。
2.在以前的报告中估计了整个湖泊（Maberly 2008年，2009年）的集水区和WwTW的营养负荷，但在此计算了流域特定负荷。建模工作是使用基于1998年的藻湖模型CNOH进行的。该模型产生了一个很好的代表性的浮游植物叶绿素a的季节性变化，也成功地模拟了藻类的类型。
3.在1997年至2007年期间，来自WwTW的SRP直接排放的平均贡献为温德米尔北部盆地总负荷的30%，但为南部盆地总负荷的52%。在1998年，即模拟工作所用的年份，这一差异甚至更大，北部和南部盆地分别为15%和62%。
4. WwTW对各自流域的不同贡献转化为每个流域对WwTW SRP负荷减少的响应。在北海盆，即使从安布莱赛德的WwTW完全去除SRP负荷，也仅导致年平均浮游植物叶绿素a减少11%。相比之下，在南部盆地完全去除SRP负载从温德米尔WwTW将导致54%的年度平均浮游植物叶绿素a减少。然而，这些差异是一致的，观察到的最低限度的减少冬季浓度的SRP和TP在北盆地三级治疗后，在1992年，而大量减少已记录在南盆地。
5.进一步清除安布莱赛德污水处理厂的SRP虽然有利，但并不足以进一步显著改善北盆的水质。需要更多的努力来解决磷的其他来源，包括较小的点源和来自集水区的扩散源。相比之下，严重减少SRP负荷从WwTW排放到南盆地应该有进一步的好处，减少浮游植物。
6.浮游动物吃浮游植物的影响的有限的建模没有显示出很大的影响，但一个更复杂的浮游动物吃模块是必要的（目前正在开发）之前，我们可以相信这种影响的大小。今后的模型中还需要包括处理气候变化影响的进一步工作，通过模拟更多年份，可以使预测更加可靠。
1. The purpose of this report was to establish the effect of reduced nutrient loading from the two wastewater treatment works (WwTW) at Ambleside and Tower Wood on the amount and types of phytoplankton in the two basins of Windermere. A secondary objective was to assess the likely impact of reduced grazing pressure by zooplankton on phytoplankton amount.
2. The nutrient loads from the catchment and the WwTWs were estimated in previous reports for the whole lake (Maberly 2008, 2009) but basin-specific loads were calculated here. The modelling work was carried out using the algal lake model PROTECH based on the year 1998. The model produced a good representation of the seasonal changes in phytoplankton chlorophyll a and also successfully simulated the types of algae present.
3. The mean contribution of direct discharge of SRP from WwTW between 1997 and 2007 was 30% of the total load in the North Basin but 52% of the total load in the South Basin of Windermere. In 1998, the year used for the modelling exercise, this difference was even greater at 15% and 62% for the North and South Basin respectively.
4. The differential contribution of the WwTWs to their respective basin translated across to the responsiveness of each basin to reductions in SRP loading from the WwTW. In the North Basin, even complete removal of the SRP load from the WwTW at Ambleside only caused an 11% decrease in annual mean phytoplankton chlorophyll a. In contrast, in the South Basin complete removal of the SRP load from the Windermere WwTW would cause a 54% decrease in annual mean phytoplankton chlorophyll a. However, these differences are consistent with the observed minimal reduction in winter concentrations of SRP and TP in the North Basin following tertiary treatment in 1992, while substantial reductions have been recorded in the South Basin.
5. Further removal of SRP from the Ambleside WwTW, while beneficial, will not be sufficient to cause a marked further improvement in water quality in the North Basin. More effort will be needed to tackle other sources of phosphorus including smaller point sources and diffuse sources from the catchment. In contrast, severely reducing the SRP load from WwTW discharging to the South Basin should have a further benefit in reducing phytoplankton.
6. The limited modelling of the effect of zooplankton grazing on phytoplankton did not show a large effect but a more sophisticated zooplankton grazing module is needed (and is currently being developed) before we can be confident about the magnitude of this effect. Further work addressing the effect of climate change will also need to be included in future models and the forecasts could be made more robust by modelling additional years.