SosteniPrA (ICTA-IRTA-Inèdit), Institute of Environmental Science and Technology (ICTA), Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Barcelona, Spain.
Water Res. 2011 May;45(10):3245-54. doi: 10.1016/j.watres.2011.03.036. Epub 2011 Mar 29.
Roofs are the first candidates for rainwater harvesting in urban areas. This research integrates quantitative and qualitative data of rooftop stormwater runoff in an urban Mediterranean-weather environment. The objective of this paper is to provide criteria for the roof selection in order to maximise the availability and quality of rainwater. Four roofs have been selected and monitored over a period of 2 years (2008-2010): three sloping roofs - clay tiles, metal sheet and polycarbonate plastic - and one flat gravel roof. The authors offer a model for the estimation of the runoff volume and the initial abstraction of each roof, and assess the physicochemical contamination of roof runoff. Great differences in the runoff coefficient (RC) are observed, depending mostly on the slope and the roughness of the roof. Thus, sloping smooth roofs (RC>0.90) may harvest up to about 50% more rainwater than flat rough roofs (RC=0.62). Physicochemical runoff quality appears to be generally better than the average quality found in the literature review (conductivity: 85.0 ± 10.0 μS/cm, total suspended solids: 5.98 ± 0.95 mg/L, total organic carbon: 11.6 ± 1.7 mg/L, pH: 7.59 ± 0.07 upH). However, statistically significant differences are found between sloping and flat rough roofs for some parameters (conductivity, total organic carbon, total carbonates system and ammonium), with the former presenting better quality in all parameters (except for ammonium). The results have an important significance for local governments and urban planners in the (re)design of buildings and cities from the perspective of sustainable rainwater management. The inclusion of criteria related to the roof's slope and roughness in city planning may be useful to promote rainwater as an alternative water supply while preventing flooding and water scarcity.
屋顶是城市雨水收集的首选。本研究整合了城市地中海气候环境中屋顶雨水径流的定量和定性数据。本文的目的是提供屋顶选择的标准,以最大限度地提高雨水的可用性和质量。选择了四个屋顶进行监测,监测时间为 2 年(2008-2010 年):三个倾斜屋顶 - 粘土瓦、金属板和聚碳酸酯塑料 - 和一个平坦砾石屋顶。作者提供了一种估算每个屋顶径流量和初始截留量的模型,并评估了屋顶径流水的理化污染。根据屋顶的坡度和粗糙度,径流系数(RC)存在很大差异。因此,倾斜平滑屋顶(RC>0.90)比平坦粗糙屋顶(RC=0.62)可能多收集多达 50%的雨水。理化径流水质似乎普遍优于文献综述中发现的平均水质(电导率:85.0 ± 10.0 μS/cm,总悬浮固体:5.98 ± 0.95 mg/L,总有机碳:11.6 ± 1.7 mg/L,pH 值:7.59 ± 0.07 upH)。然而,对于一些参数(电导率、总有机碳、总碳酸盐系统和铵),倾斜和平坦粗糙屋顶之间存在显著差异,前者在所有参数中表现出更好的质量(铵除外)。这些结果对于地方政府和城市规划者从可持续雨水管理的角度重新设计建筑物和城市具有重要意义。在城市规划中纳入与屋顶坡度和粗糙度相关的标准,可能有助于促进雨水作为替代水源,同时防止洪水和水资源短缺。