Sustainable Drainage Systems (SuDS) retrofit planning: a scalar approach to site prioritisation

肥皂提供了一种控制城市弥漫污染、降低洪水风险、减少联合下水道溢流的发生率的手段，还可能具有美化市容的价值。然而，即使新建筑的SOD不会对相关场地的扩散负荷和排放制度产生净变化，现有城市发展的遗留问题意味着洪水风险和扩散污染问题将不会得到解决。到2050年，我们将拥有的所有开发项目的大部分已经建成，显然需要将肥皂水改造到现有的建成环境中。改造肥皂水比新建肥皂水带来更大的挑战，原因有两个。首先，在建筑环境中的哪些地方最需要肥皂水存在很大的不确定性。这一点很重要，因为与新建筑相比，翻新肥皂水的监管驱动因素较少，因此重要的是要相信任何投资都是在正确的地方进行的。其次，改装肥皂水面临着更大的物理、经济和社会挑战。一般来说，我们可以假设需要高SOD的区域也发生在实施限制最大的区域。因此，在任何建筑环境中，考虑到需要和可行性，可能会有一系列最适合进行肥皂水改造的地点。这项研究的目的是通过考虑需要和可行性，确定如何最好地确定在给定的城市化集水区的哪些地方进行肥皂水改造的最佳地点。

SuDS provide a means of controlling urban diffuse pollution, reducing flood risk, incidence of combined sewer overflow, and may also have amenity value. They are most commonly implemented with respect to new build however, even if SuDS for new build result in no net change to the diffuse load and discharge regime of the site in question, the legacy of extant urban development means that flood risk and diffuse pollution problems will not be addressed. The bulk of all development we will have in 2050 has already been built, and there is a clear need for SuDS retrofit into the existing built environment.Retrofit SuDS offer a greater challenge than new build SuDS for two reasons. First, there is significant uncertainty over where in the built environment SuDS are needed most. This is important as, compared to new build, there are fewer regulatory drivers for retrofit SuDS and so it is important to be confident that any investment is made in the right places. Second, retrofit SuDS face greater physical, economic and social challenges. In general, we can assume that areas of high SuDS need occur in areas where the implementation constraints are also greatest. There is therefore likely to be a series of sites within any built environment which are optimal for SuDS retrofit, considering need and feasibility.The purpose of this research is to determine how best to identify where, in a given urbanised catchment, the optimal sites for SuDS retrofit are through consideration of need and feasibility.