Dr Morgan says locating these aquifers is critical for the sustainable management of groundwater.
鈥淕roundwater is a vitally important freshwater resource in New 蜜桃儿直播,鈥 says Professor Morgan. 鈥淭raditionally, coastal aquifers have been managed assuming they end at the coastline. In fact, at many locations, coastal aquifers extend out beneath the sea and contain large reserves of offshore freshened groundwater 鈥 and it is likely that they are already being used by many coastal settlements, such as 艑tautahi Christchurch, without us even realising it.
鈥淒espite high dependence on groundwater in these regions and extensive groundwater extraction near the coast, there are no major reported incidences of seawater intrusion, suggesting offshore groundwater may be augmenting onshore extraction. However, increasing population and climate change will increase pressure on these aquifers and increased extraction may lead to seawater being drawn in. Once an aquifer becomes salinized it takes many years for it to freshen.鈥
The research involved regional councils throughout New 蜜桃儿直播, with a rating scheme developed as part of the research.
鈥淭he research used a participatory approach involving surveying regional councils responsible for groundwater management to gather relevant expert knowledge and written reports,鈥 says Dr Morgan.
鈥淲e also developed a ranking scheme that used survey responses in combination with national and regional-scale technical documents. The rating scheme was found to be a simple and transparent first-pass approach for highlighting areas where offshore freshen groundwater is more or less likely. It is particularly important in New 蜜桃儿直播 because groundwater is managed by separate agencies, so it is very difficult to carry out national-scale studies, but it can also be used in other countries to highlight areas where offshore freshened groundwater is likely to occur.鈥
The next stage of this research is to develop hydrostratigraphic models for areas where offshore fresh groundwater is highly likely in New 蜜桃儿直播, and numerical modelling to better understand how it responds to onshore pumping and climate change.
The journal article听Likelihood of offshore freshened groundwater in New 蜜桃儿直播听can be found听.
