Wetlands Ecology and Management

, Volume 23, Issue 2, pp 167–182

A hydrologic tracer study in a small, natural wetland in the humid tropics of Costa Rica

  • D. Kaplan
  • M. Bachelin
  • C. Yu
  • R. Muñoz-Carpena
  • Thomas L. Potter
  • W. Rodriguez-Chacón
Original Paper

DOI: 10.1007/s11273-014-9367-1

Cite this article as:
Kaplan, D., Bachelin, M., Yu, C. et al. Wetlands Ecol Manage (2015) 23: 167. doi:10.1007/s11273-014-9367-1

Abstract

Growing populations and food demand in the tropics are leading to increased environmental pressures on wetland ecosystems, including a greater reliance on natural wetlands for water quality improvement. Effective assessment of wetland treatment potential requires an improved understanding of the hydraulic and biogeochemical factors that govern contaminant behavior, however detailed studies of flow through natural, tropical wetlands are scarce. We performed a tracer study using a conservative salt (potassium bromide) to examine the hydraulic behavior of a small, natural wetland in the Costa Rican humid tropics and modeled observed breakthrough curves using the 1-D advection–dispersion equation. Velocities in the wetland were extremely slow, from less than 4 m day−1 to a maximum of ~30 m day−1, and were distributed across several flowpaths, illustrating a spatial heterogeneity of flow and velocities. Modeled dispersion coefficients were also low (33 ± 33 mday−1). Estimated residence times suggested high potential pollutant removal capacity over a range of influent concentrations, reinforcing the environmental services provided by this and other small tropical wetlands. The study also highlighted how small variations in wetland topography and vegetation yield strong differences in transport patterns that affect transport and mixing in densely vegetated, heterogeneous wetland systems. Empirical data on the hydraulics, and resulting ecosystem functions, of small, distributed wetlands may provide support for improved conservation and management of these important ecosystems.

Keywords

Tracer study Wetland hydrology Bromide Residence time Water quality Humid tropics Ecosystem services 

Abbreviations

Br

Bromide

BTC

Breakthrough curve

τ

Residence time

Copyright information

© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  • D. Kaplan
    • 1
    • 2
  • M. Bachelin
    • 2
    • 3
  • C. Yu
    • 2
  • R. Muñoz-Carpena
    • 2
  • Thomas L. Potter
    • 4
  • W. Rodriguez-Chacón
    • 5
  1. 1.Environmental Engineering Sciences Department, Engineering School of Sustainable Infrastructure and EnvironmentUniversity of FloridaGainesvilleUSA
  2. 2.Agricultural and Biological Engineering DepartmentUniversity of FloridaGainesvilleUSA
  3. 3.Section Sciences et Ingénierie de l’EnvironnementÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
  4. 4.USDA-ARS Southeast Watershed LaboratoryTiftonUSA
  5. 5.EARTH UniversitySan JoséCosta Rica

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