Auckland Technical Meetings

The New Zealand National Chapter of the International Association of Hydrogeologists (IAH) would like to invite you to the upcoming Auckland technical meeting scheduled for Tuesday 12 November 2019, from 5:30 pm to 7:30 pm.  The presentation will start around 6:00 pm.

Hangjian Zhao (Hydrogeologist at Williamson Water & Land Advisory) will be presenting his research paper.  The meeting will be held at the Beca office, located at Beca House, 21 Pitt Street, Auckland 1010.  Beca will be sponsoring the event and providing nibbles and drinks.

Access to parking  at the Beca office is off Hopetoun St. If you require parking, please let Breda know by email at breda.savoldelli@beca.com. 

The title of Hangiian’s paper is:

“Evaluating seepage lake drought resilience using stable isotopes of water and groundwater-flow models”

Abstract

Stable isotopes of water are a conservative tracer that can facilitate the unique estimation of lake water-budget components. Isotope fractionation processes allow different water-budget components to be distinguished based on their isotopic compositions. Fractionation during evaporation, which preferentially removes the lighter isotopes, results in heavier oxygen-18 (18O) and deuterium (D) signatures in lakes compared with groundwater recharged by snow and rainfall. Conventional water budget methods can be coupled with an 18O mass balance model to quantify groundwater and surface-water interactions in such lakes.

 Individual 18O mass balance models are developed for 18 seepage lakes in Chequamegon-Nicolet National Forest, Northern Wisconsin. The hydrological and 18O components of the isotope budgets come from different sources and analytical methods. The results from 18O mass balance models were also combined with the results of a GFLOW analytic element groundwater model.

Figure 4-16: Stable isotope compositions of 18 seepage lakes and the calculated stable isotope compositions of evaporation fluxes