WORLD GREEN INFRASTRUCTURE AWARD
Rain garden responses to real rainfall events
Category:
GREEN INFRASTRUCTURE RESEARCH AND ACADEMIC WORK
Project creators
Poland
Country
Wroclaw
City
Wroclaw University of Environmental and Life Sciences
Institution
PostDoc
Nominator Degree Program
Ewa Burszta-Adamiak
Nominator
Project specifications
Research includes physical testing
or observation location
Location City(s)
Main location Country
Other countries list
YES
Wrocław
Poland
Polska
Project Abstract
Originality Declaration
Consent for Use of Materials
The submitted achievement is an original reserach paper entitled: Rain garden hydrological performance - responses to real rainfall events by: Ewa Burszta-Adamiak, Małgorzata Biniak-Pieróg, Paweł Dąbek and Aleksandra Sternik published in the journal Science of the Total Environment, Elsevier (DOI: http://dx.doi.org/10.1016/j.scitotenv.2023.164153). The subject matter presented in the manuscript is in line with the global trend towards sustainable stormwater management. Our research focuses on the evaluation of the ability of a field rain garden to retain runoff under different rain events and the assessment of substrate moisture variability. The results obtained are important in providing guidelines for the design of bioretention cells and methodological support for urban planners and other stakeholders in planning and implementing rain gardens on a larger scale in urban areas.
All field research and analyses of the results were carried out on their own by the authors of the publication. As practice shows, investors focusing on the construction of the systems and their commissioning skip their monitoring during the operating period, thus missing the opportunity to obtain reliable data on their hydrological performance under actual field conditions. In this context, the results obtained represent an original approach to the hydrological performance of rain gardens.
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Research details
Breef research description
Poland
Source of funding
Poland
The Research type
The Research relates to
Source of funding
rain garden
environmental issues
university
Year of construction
Year of research completion
Area brutto (m2)
2019
2021
7
Research outcomes
Is the research a precursor to expected follow up research?
Yes, we consider this research to be preliminary. The authors are continuing their research. From the point of view of building a sponge city on a large scale, it is important to scientifically determine the layout plan of rain gardens for controlling urban rainfall and flooding problems, given the topographical features and rainfall runoff characteristics of urban areas. Research will also be carried out into the development of biodiversity and natural succession (the spontaneous appearance of new species create favourable conditions for various groups of animals, e.g. pollinators, beetles. A model using machine learning tools will also be developed to determine the rain garden's response to rainfall and its potential for rainwater retention and infiltration, based on field monitoring data.
How does the research address the issue of water stewardship?
In urban areas, the increased proportion of sealed surfaces and the increased frequency of heavy rainfall are leading to flooding and even inundation. More specifically, in our paper we analyse the answers to the following questions: Is the rain garden able to manage roof runoff during heavy rainfall events? How does rainfall intensity affect the response of the rain garden? During which rainfall events does direct infiltration occur and when does temporary retention occur? Does the rain garden overflow during rainfall events that occur in the study area? How does soil moisture affect the occurrence of runoff retention or infiltration in the rain garden?
How does the research address the human well-being aspects of GI?
No, but the research presented in this paper has been conducted in an urban area, which suffers from insufficient rain-runoff management. Green infrastructure is used to deal with urban runoff at the source. Therefore, the use of sustainable rainwater management methods such as rain gardens in urban areas can reduce property damage and activity disruption due to insufficient sewer network capacity.
How does the research address the economic aspects of GI?
No
How does the research address the environmental sustainability aspects of GI?
As an engineering structure, rain gardens can help mitigate the negative effects of runoff by increasing the retention capacity of the catchment and minimize the negative environmental impact of rapid urban sprawl and climate change. Our analysis showed that the formation of the ponding time and the level of water was influenced not only by the amount of rainfall but mainly by its intensity. Runoff retention efficiency was 100 % for the whole monitoring period. The rain garden managed a total of 4.92 m3 of runoff through direct infiltration and 22.67 m3 after retaining runoff in the garden for several minutes during rainfall. This proves that even relatively small green infrastructure solutions contribute to improving local rainwater management in cities and are important for engineering practice to identify important factors in sizing bioretention facilities.
How does the research address social aspects of GI?
No, but the rain garden is located on the grounds of a High School where pupils can observe the measurements and develop an awareness of the role of green infrastructure systems in local stormwater management.
How does the research address the topic of biodiversity?
No, but rain gardens in addition to their hydrological aspect enrich biodiversity - in terms of plants and animals, developing complete ecosystems, contributing to promote other ecosystem services. Therefore, a very strong emphasis was placed on the selection of plant species in analyzed rain gardens.
What types of GI multifuncionality are addressed by the nominated research?
The research and analysis carried out on the rain garden in full scale allowed to assess the effectiveness of the operation of such a facility during the occurrence of rainfall episodes of different characteristics. There is a limited knowledge of field hydrological studies based on continuous high resolution rainfall and water ponding time and height measurements, particularly for bioretention cells. In this research laser disdrometer and hydrostatic water level probe were used to continuously monitor rainfall depth and intensity as well as ponding water level at one-minute intervals. The moisture of the vegetation layer was measured at a depth of 5 cm during 22 measurement campaigns fairly evenly spaced over time (once a week). The time domain reflectometry method (TDR) was used for the measurements.
Does the research support innovation?
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