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

Journal of Hydrology: Regional Studies

Amandine Bosserelle¹  Crile Doscher²  Leanne Morgan³  Irene Setiawan⁴  Kelvin Ng⁵ 

[1] College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia;Corresponding author at: Faculty of Environment, Society and Design, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand.;Waterways Centre for Freshwater Management, University of Canterbury, Private Bag 4800, New Zealand;Faculty of Environment, Society and Design, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand;Waterways Centre for Freshwater Management, University of Canterbury, Private Bag 4800, New Zealand;

关键词: Water table;    Specific conductance;    Groundwater salinization;    Coastal aquifer;    Saltwater intrusion;    Infrastructure;   

DOI  :  

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown