Graduation Year


Document Type




Degree Name

Master of Science (M.S.)

Degree Granting Department

Geography, Environment and Planning

Major Professor

Philip van Beynen, Ph.D.

Committee Member

Anthony Menicucci, Ph.D.

Committee Member

Patricia Spellman, Ph.D.


Isotope hydrology, Karst, Spring, Stable isotope


A stable isotope study was carried out using precipitation, spring water, groundwater well sample, and a seawater sample during the wet season in the Sulphur Springs watershed in Tampa, Florida. Studies that track long term isotopic variation over wet seasons are limited in the region. To fill this knowledge gap, this study aims to quantify the contributions of precipitation and diffuse sources to discharge in Sulphur Springs. A three-component mixing model was applied using δ18O and δ2H values to determine different source water contributions to spring water discharge. The three-component mixing model calculations suggest spring water consists mainly of diffuse water sources, up to 76.98%. The spring water contains significant proportion of saltwater with the proportion of 21.6% while precipitation contributes 16.4% of the spring discharge for the whole study period. For this short four-month, which may not reflect the entire year’s physical situation, the mixing model results show that recharge input from a precipitation does not contribute significantly to the karstic spring discharge. The study’s results show that with the use of δ18O and δ2H, insights can be provided into the various short-term contributions of the various water sources to a karstic spring located in an urban area using δ18O and δ2H.