The implementation of rainwater harvesting (RWH) has emerged as a key strategy to cope with the water crisis in urban areas. However, the required design parameters of the RWH system in different buildings vary widely because of the differences in architectural characteristics. In this paper, the relationships between the building characteristics parameters and the optimal tank (T_c) capacity are investigated by simulating the RWH system for more than 120 buildings at different locations in Guangzhou. Explicit expressions relating the optimal storage volume of RWH systems to building characteristics are derived based on nonlinear regression analysis. A set of bivariate exponential equations for estimating the optimal tank size under different building conditions was obtained. The model has a MER of less than 10% for buildings with a C/D ratio between 17.5 and 85. In Guangzhou, the unit cost of an RWH system can be reduced to CNY 2.62/m² with optimally designed tanks.

中文翻译：

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RWH系统优化设计解析解的开发——以广州为例

实施雨水收集（RWH）已成为应对城市地区水危机的关键战略。然而，由于建筑特点的差异，不同建筑的RWH系统所需的设计参数差异很大。本文通过模拟广州不同地点的 120 多座建筑的 RWH 系统，研究了建筑特征参数与最佳水箱容量( T _{c ) 之间的关系。}基于非线性回归分析，推导了 RWH 系统最佳存储量与建筑特性的显式表达式。获得了一组用于估计不同建筑条件下最佳水箱尺寸的双变量指数方程。对于C/D 比在17.5 至85 之间的建筑物，该模型的MER 小于10%。在广州，通过优化设计的水箱，RWH 系统的单位成本可降低至2.62 元/m ²。