Understanding Surface and Ground Water Interaction, and Water Quality using Stable Isotopes and Major Ions

Understanding Surface and Ground Water Interaction, and Water Quality using Stable Isotopes and Major Ions

Presenter(s)

Caroline Johnstone

Description

Stable isotopes of oxygen and hydrogen are conservative dual tracers and provide key information about movement of water in the hydrologic cycle. Surface and groundwater are important components in the water cycle that variably interact depending on geology, topography and rainfall seasonality. Understanding the degree of this interaction is critical to determine both the quality and quantity of water. Here, we use stable isotopes of oxygen and hydrogen, and geochemical analysis of water to quantify the degree of interaction between surface and groundwater. This approach solely depends on the water chemistry and unique isotopic composition of seasonal rainfall, surface and groundwater. Water isotope data in the region is very limited to monthly precipitation isotope data in Coshocton, OH monitored by the Global Networks of Isotopes in Precipitation. To fully use this powerful tracing technique in hydrology, water resources and climate studies, establishing the seasonal variability of water isotopes in the surface and groundwater is a critical first step. Here we present a weekly water isotope data collected at four locations, Still Water River, Mad River and two locations at the Great Miami River. River and groundwater sample collection for isotopic and geochemical data analysis will continue the rest of the year to obtain seasonal isotope end members. However, our preliminary data collected for fall 2018 shows that the average isotopic composition of the rivers is 6.82‰ for δ 18 O and 43.24‰ for δD, and groundwater average 7.08‰ for δ 18 O and 44.46‰ for δD. Using this data, we employed an isotope mass balance to determine the degree of surface and groundwater interaction. Preliminary results suggest that the Miami River could contribute up to 90% recharge to the buried aquifer. The overall outcome of this research will help to quantify seasonal groundwater recharge and determine the fate of contaminants to the local aquifer.

Publication Date

4-18-2018

Project Designation

Capstone Project

Primary Advisor

Zelalem K. Bedaso

Primary Advisor's Department

Geology

Keywords

Stander Symposium project

Understanding Surface and Ground Water Interaction, and Water Quality using Stable Isotopes and Major Ions

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