PhD defence: Jan Støvring
Jan Støvring defends his thesis,
Urban Surfaces in a New Era:
Planning and designing with permeable pavement systems for storm water management
Associate Professor Torben Dam, IGN
Professor Marina B. Jensen, IGN
Senior Lecturer Andrew Clayden, The University of Sheffield
Senior Lecturer Rolf Larsson, Lund University
Professor Gertrud Jørgensen (chair), IGN
Pluvial floods in highly urbanized areas are a frequently occurring problem for society due to intense rainstorms and the continuous sealing of the urban landscape. Permeable pavement (PP) systems offer more benefits for dealing with pluvial floods. The aim of this thesis is two-fold: 1) to explore the hydrological performance of PP systems as a means of supporting urban storm water management, and 2) to assess the planning and design prerequisites for this performance as a means of strengthening urban resilience.
The research for this PhD thesis included three studies, each with their own specific aims. In Study I, four types of PP surfaces and three types of sub-base aggregates were combined and tested when built as six independently lined constructions into an existing parking area in Copenhagen. In Study II, a multiple case study, nine existing PP systems were tested for their surface permeability in two periods with an interval of one year and the results related to each site’s unique history of sedimentation. In Study III, a single-case study was used to explore suitable areas for converting existing paved areas on municipal land to PP systems, with due respect to spatial constraints. To highlight the potential hydraulic benefits of a conversion, calculations were made for a 10-year and 100-year design storm. Results show considerable variation in annual reductions of storm water volumes among the six PP systems tested. Variation ranged from almost zero to one-third, while volume reduction and lag-time to single events were more homogeneous across the PP system tested. Performance was associated with surface properties as well as sub-base aggregate properties (Study I). On-site sedimentation factors, particularly the perimeter design and adjacent land cover and land use, affect the surface permeability, potential to a level that override the effect of maintenance. This finding underscores the importance of proactive design and planning (Study II). In a dense urban context, there is considerable potential for siting PP systems. Regardless of whether the PP systems are unlined or lined, the hydraulic capacity is considerable and could be a valuable asset in addressing pluvial floods and storm water management on a city-wide scale (Study III).
The studies described in this PhD thesis demonstrate that PP systems can contribute to improved urban storm water management, better landscape design and enhanced urban resilience.
The thesis is available for inspection at the PhD administration office 04.1.413, Øster Voldgade 10