Download Connection between geological heterogeneity and area in Denmark

NOVATECH 2013
Connection between geological heterogeneity and
hydrological performance of SUDS in a peri-urban
area in Denmark
Connecter l'hétérogénéité géologique et les
performances hydrauliques de SUDS dans un secteur
péri-urbain du Danemark
Britta Bockhorn, Knud Erik Klint, Marina Bergen Jensen
Department of Geosciences and Natural Resource Management, University
of Copenhagen, Copenhagen, Denmark ([email protected])
ABSTRACT
Climate change, urban densification and a growing concern of eco-environmental issues call sewerbased urban drainage systems into question. Infiltration of stormwater runoff into the soil can be an
alternative to a cost-intensive enlargement of the existing sewer system. Most Danish cities are
located on low water-permeable glacial deposits where infiltration of stormwater runoff poses a major
challenge (Hermansen et al. 2000).
The objective of this project is to investigate non-destructive infiltration methods for stormwater runoff
into low permeable glacial sediments. The Danish city Mårslet, 10 km South of Århus, is located on a
clay till site and serves as the experimental area for this study. Geophysical investigations and field
studies on fractures and biopores which serve as hydraulic flow-paths through an otherwise
impermeable clay (Fredericia 1990; Hendry 1982; Klint et al. 2001) show a vast geologic variability for
the site. The results give different options for infiltration strategies of stormwater runoff.
The hypothesis is that the infiltration rate can be enhanced by the exploitation of the site specific
geologic and hydraulic variability. In that way the efficiency of water sensitive urban designs can be
increased significantly. Identifying the optimal location for the installation of infiltration trenches, as well
as more advanced technologies to stimulate the hydraulic performance of the subsurface will be
investigated, thus facilitating optimal conditions for the infiltration of surface water.
References:
Fredericia, J (1990): Saturated hydraulic conductivity of clayey tills and the role of fractures. Nord Hydrol 25:119–
132.
Hendry, MJ (1982): Hydraulic conductivity of a glacial till in Alberta. Ground Water. 20(2):162–169.
Hermansen, B.; Jakobsen, P.R. (2000): Danmarks digitale jordartskort 1:25 000. Danmarks og Grønlands
Geologiske Undersøgelse, version 2,0, GEUS rapport nr. 81, 2000.
Klint, K.E.S.; Abildtrup, C.A.; Gravesen, P.; Jakobsen, P.R.; Vosgerau, H. (2001): Sprækkers oprindelse og
udbredelse i moræneler i Danmark. Vand og Jord 8, 3, 111-119.
KEYWORDS
Glacial deposits, infiltration, stormwater management, SUDS
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A7 - OUTILS AMÉNAGEURS & DD / PLANNER TOOLS & SD
In what aspects does this case study:
Integrate stormwater?
Objective of this study is to investigate techniques for an enhanced infiltration of stormwater run-off
into low permeable soils.
Has a sustainable approach?
The outcome will give an important contribution to an improved work efficiency of green technologies
for stormwater infiltration and consequently be beneficial for climate change adaption.
Is innovative?
The case study takes the geological variability of a clay soils into account to enhance infiltration of
stormwater run-off.
Is applicable to other projects?
The case study can be transferred to regions which are covered by low permeable clay sediments and
where the infiltration of stormwater run-off consequently poses a challenge.
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