Future Coasts: Assessing groundwater hazards associated with relative sea-level rise

MBIE Endeavour
2021-2026

Team

Dr Leanne Morgan, Dr Wes Kitlasten (GNS), Zeb Etheridge (Komanawa), Irene Setiawan, Amandine Bosserelle, Connor Cleary, Desmond McCoy, Matthew Jones

The problem

Aotearoa New Zealand’s coastal lowlands are flat low-lying land adjacent to coasts and estuaries. These coastal lowlands are popular places to live and valued for many reasons, including unique ecological wetlands, cultural sites of significance, recreational areas, highly-productive agriculture. Sea-level rise will force changes to coastal lowlands and our use of these environments.

Research approach

This project examines exposure to relative sea-level rise and linked compound groundwater hazards (flooding and salinization) in New Zealand’s coastal lowlands. Monitoring and modelling methods for assessing change in near-shore shallow groundwater will be assessed and validated at selected New Zealand case study areas, including the coast between the Ashley and Waimakariri Rivers in Canterbury. The detailed case study research will inform the design of a national-scale model that aims to predict coastal shallow groundwater level and salinity under several relative sea-level rise scenarios, out to 2100. 

Project Partners:

NIWA
GNS
Komanawa Solutions Ltd.
Future Coast Aotearoa

Outputs:
Setiawan I., Morgan L. and Doscher C. (2023) Saltwater intrusion from a tidal river: a field investigation. Journal of Hydrology 617(Part A) 128955 http://doi.org/10.1016/j.jhydrol.2022.128955

Bosserelle A, Morgan LK, Hughes, M (2022) Groundwater Rise and Associated Flooding in Coastal Settlements Due To Sea‐Level Rise: A Review of Processes and Methods, Earth’s Future 10(7), https://doi.org/10.1029/2021EF002580

Morgan LK, Mountjoy J (2022) Likelihood of offshore freshened groundwater in New Zealand, Hydrogeology Journal https://doi.org/10.1007/s10040-022-02525-1

Setiawan I., Morgan L., Doscher C., Ng K. and Bosserelle A. (2022) Mapping shallow groundwater salinity in a coastal urban setting to assess exposure of municipal assets. Journal of Hydrology: Regional Studies 40 http://doi.org/10.1016/j.ejrh.2022.100999

Setiawan I., Morgan L., Doscher C., Ng K. and Bosserelle A. (2022) Christchurch shallow groundwater quality survey dataset. Data in Brief 41 http://doi.org/10.1016/j.dib.2022.107982