Features of Roof Rainwater Runoff Pollution in a Northern Coastal City under the Effects of Multiple Factors

Abstract

This paper attempts to disclose the features of roof rainwater runoff pollution under the effects of air pollution, season, rainfall intensity, and antecedent dry period. Targeting an inclined tile roof in Yantai, China, this paper samples rainwater multiple times from March to November, 2018. The quality of roof rainwater samples in 12 representative natural rainfalls was monitored, and the curves of the main pollutants in these samples were plotted. On this basis, the authors analyzed the change features and outflow laws of the main pollution indices of roof runoff rainwater under the effects of different factors. The results show that: The degree of air pollution directly bears on rainwater quality. The rainfall also has a certain impact on air pollution indices. Season is the leading influencing factor of the quality of roof runoff rainwater. The best rainwater quality was observed in autumn, followed by that in spring and then that in summer. In the first 10-20min of each rainfall, the pollutant contents decreased at a growing rate with the increase of rainfall intensity. The increments of the initial pollutant contents reached the maximum at the antecedent dry period of 10d. The changes of all pollution indices of roof runoff rainwater could be divided into the sudden change phase, the transition phase, and the stable phase. Roof rainwater runoff has an obvious initial washing effect, and exerts a secondary washing effect. The research results provide a good reference for northern coastal cities to rationalize the parameters of rainwater purification facilities.

Stormwater Harvesting from Roof Catchments: A Review of Design, Efficiency, and Sustainability

“…No filtration of articles from specific years was performed. The resulting documents were downloaded as a Research Information System (RIS) file on Water 2023, 15, 1774 3 of 22 23 August 2022 and parsed into a corpus using the CorText manager, an online software used to quantitatively assess scientific articles based on bibliometric information collected from a set of downloaded research articles [22]. Various scripts that include a network map of keywords, years, and countries, contingency matrices (keyword and journal; keyword and country), and a Sankey diagram of keywords were generated from the CorText Manager for the analysis of terms, references, and trends of topics related to roofing rainwater harvesting.…”

“…Roof rainwater quality can be influenced by a variety of factors, including roof characteristics (e.g., material, age, slope), environmental factors (air pollution, geographic location, season), and rainfall characteristics (rainfall intensity, antecedent dry period, rainfall duration). Studies have stated that pollutants accumulate both in the air and on the roof from the onset of rainfall until the emergence of roof runoff [23]. Rainwater harvesting components and external factors, such as climatological conditions, including rainfall intensity and dry days, also influence the quality of rainwater runoff [24].…”

“…The identification of contaminants and the conditions in which they arise can help to develop rules, regulations, and maintenance recommendations for small-scale rainwater harvesting [26]. Common contaminants from roof runoff include zinc, copper, and iron [27], although their concentration can depend on the roofing materials, environmental factors, and rainfall characteristics [23].…”

Roof-Integrated Green Technologies, Energy Saving and Outdoor Thermal Comfort: Insights from a Case Study in Urban Environment

“…New green roofs and walls improve buildings performance with a significant reduction in energy consumptions by reducing the absorption of solar radiation and mitigating UHI effect. The main advantages concern the contribution to thermal insulation, acoustic insulation, ecological preservation, mitigation of summer temperatures, attenuation of rainwater runoff and an aesthetic improvement of the property increasing building value [17][18][19][20][21].…”

Traceability of River Water Pollution Based on MFO and M-H Algorithms

“…Research on water pollution incidents focuses on spatio temporal dynamic changes in water quality [8,9], pollution causes [10], pollutant sources [11][12][13], and the traceability of water pollution sources [14][15][16][17][18][19]. Accidental pollutants will convene and spread in the river as water pollution incidents happen.…”