Gires Auguste, de Gouvello Bernard
Université Paris-Est, Leesu, UMR MA 102 AgroParisTech, 6-8 avenue Blaise Pascal, F 77455, Marne la Vallée cedex 2, France.
Water Sci Technol. 2009;60(3):543-53. doi: 10.2166/wst.2009.361.
The collection, storage and use of rainwater from roofs reduce the need for potable water. However, if water suppliers are to decrease their infrastructure costs as well as their operational costs (due to water savings), the rainwater system has to provide most of the time a significant percentage of the water demand. This paper adopts the viewpoint of the water suppliers and investigates how reliable this source of water is in the case of a housing estate, considering WC flushing as the only water demand. A housing estate was modelled and different realistic input scenarios (water demand for WC flushing, storage capacity, roof area, and rainfall) were defined. Three indicators were exhibited. The variability generated by each input on the indicators was evaluated. The indicators were estimated for 63 homogeneously distributed French cities. Among the indicators exhibited in this paper, the most relevant one is the percentage of water supplied from the tank that is secured during 95% of the days of the simulation. The main conclusion is that the optimum way of determining the storage capacity of the rainwater collection system is not the same from the viewpoint of the users than from the viewpoint of the water suppliers. Indeed, water suppliers tend to require bigger tanks in order to take into account the rainwater collection systems in their management plan.
收集、储存和使用屋顶雨水可减少对饮用水的需求。然而，如果供水公司想要降低基础设施成本以及运营成本（由于节水），雨水系统必须在大多数时间满足很大一部分用水需求。本文从供水公司的角度出发，以住宅区内的厕所冲洗作为唯一用水需求，研究了这种水源的可靠性。对一个住宅区进行了建模，并定义了不同的实际输入场景（厕所冲洗用水需求、储存容量、屋顶面积和降雨量）。展示了三个指标。评估了每个输入对指标产生的变异性。对63个分布均匀的法国城市的指标进行了估算。在本文展示的指标中，最相关的是在模拟的95%天数内，水箱供应的有保障的水量百分比。主要结论是，从用户角度和供水公司角度来看，确定雨水收集系统储存容量的最佳方法是不同的。事实上，供水公司倾向于要求更大的水箱，以便在其管理计划中考虑雨水收集系统。
