Mapping shallow groundwater salinity in a coastal urban setting to assess exposure of municipal assets

Type of content
Journal Article
Thesis discipline
Degree name
Publisher
Elsevier BV
Journal Title
Journal ISSN
Volume Title
Language
en
Date
2022
Authors
Setiawan I
Doscher C
Ng K
Bosserelle A
Morgan, Leanne
Abstract

Study region: Christchurch, New Zealand. Study focus: Low-lying coastal cities worldwide are vulnerable to shallow groundwater salinization caused by saltwater intrusion and anthropogenic activities. Shallow groundwater salinization can have cascading negative impacts on municipal assets, but this is rarely considered compared to impacts of salinization on water supply. Here, shallow groundwater salinity was sampled at high spatial resolution (1.3 piezometer/km2 ), then mapped and spatially interpolated. This was possible due to a uniquely extensive set of shallow piezometers installed in response to the 2010–11 Canterbury Earthquake Sequence to assess liquefaction risk. The municipal assets located within the brackish groundwater areas were highlighted. New hydrological insights for the region: Brackish groundwater areas were centred on a spit of coastal sand dunes and inside the meander of a tidal river with poorly drained soils. The municipal assets located within these areas include: (i) wastewater and stormwater pipes constructed from steel-reinforced concrete, which, if damaged, are vulnerable to premature failure when exposed to chloride underwater, and (ii) 41 parks and reserves totalling 236 ha, within which salt-intolerant groundwater-dependent species are at risk. This research highlights the importance of determining areas of saline shallow groundwater in low-lying coastal urban settings and the co-located municipal assets to allow the prioritisation of sites for future monitoring and management.

Description
Citation
Setiawan I, Morgan L, Doscher C, Ng K, Bosserelle A (2022). Mapping shallow groundwater salinity in a coastal urban setting to assess exposure of municipal assets. Journal of Hydrology: Regional Studies. 40. 100999-100999.
Keywords
Water table, Specific conductance, Groundwater salinization, Coastal aquifer, Saltwater intrusion, Infrastructure
Ngā upoko tukutuku/Māori subject headings
ANZSRC fields of research
0406 Physical Geography and Environmental Geoscience
0502 Environmental Science and Management
Fields of Research::37 - Earth sciences::3707 - Hydrology::370703 - Groundwater hydrology
Fields of Research::37 - Earth sciences::3707 - Hydrology::370705 - Urban hydrology
Fields of Research::41 - Environmental sciences::4105 - Pollution and contamination::410503 - Groundwater quality processes and contaminated land assessment
Fields of Research::41 - Environmental sciences::4104 - Environmental management::410402 - Environmental assessment and monitoring
Rights
All rights reserved unless otherwise stated