Urban hydrogeology

Urban hydrogeology: Transport routes and mixing of water and solutes in a groundwater influenced urban lowland catchment

Yu, Liang (Vrije Universiteit Amsterdam; Waternet; TNO)
Rozemeijer, Joachim C. (Deltares)
van der Velde, Ype (Vrije Universiteit Amsterdam)
van Breukelen, B.M. (TU Delft Sanitary Engineering)
Ouboter, Maarten (Waternet)
Broers, Hans Peter (TNO)

2019

Urban areas in coastal lowlands host a significant part of the world's population. In these areas, cities have often expanded to unfavorable locations that have to be drained or where excess rain water and groundwater need to be pumped away in order to maintain dry feet for its citizens. As a result, groundwater seepage influences surface water quality in many of such urban lowland catchments. This study aims at identifying the flow routes and mixing processes that control surface water quality in the groundwater-influenced urban catchment Polder Geuzenveld, which is part of the city of Amsterdam. Geuzenveld is a highly paved urban area with a subsurface rain water collection system, a groundwater drainage system, and a main surface water system that receive runoff from pavement and roofs, shallow groundwater and direct groundwater seepage, respectively. We conducted a field survey and systematic monitoring to identify the spatial and temporal variations in water quality in runoff, ditch water, drain water, and shallow and deep groundwater. We found that Geuzenveld receives a substantial inflow of deep, O ₂ -depleted groundwater, which is enriched in ammonium and phosphorus due to the subsurface mineralization of organic matter under sulfate-reducing conditions. This groundwater is mixed in the ditches during wet periods with O ₂ -rich runoff, and iron- and phosphate-rich drain water. Unlike natural catchments, the newly created, separated urban flow routes lead to mixing of water in the main surface water itself, shortcutting much of the soil and shallow subsurface. This leads to low O ₂ and high ammonia concentrations in dry periods, which might be mitigated by water level management or artificially increasing O ₂ levels by water inlet or artificially aeration of the main water canals. Further research is necessary how to optimize artificial urban systems to deliver a better ecological and chemical status of the surface water.

Amsterdam
Groundwater quality
Groundwater-surface water interaction
Nutrients
Radon
Surface water quality

http://resolver.tudelft.nl/uuid:4a21c5d7-3068-423e-8825-554c2f58def7

https://doi.org/10.1016/j.scitotenv.2019.04.428

2019-10-29

0048-9697

Science of the Total Environment, 678, 288-300

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

journal article

© 2019 Liang Yu, Joachim C. Rozemeijer, Ype van der Velde, B.M. van Breukelen, Maarten Ouboter, Hans Peter Broers