Jonathan M. Malzone
Ephemeral wetlands dry seasonally and are found throughout the Daniel Boone National Forest (DBNF), including on remote ridgetops. Recent research suggests some wetlands constructed in the past few decades in DBNF remain wet year round. Little research comparing hydrogeological properties of natural and constructed wetlands in DBNF is present. This project attempts to quantify spatial variability in physical properties of a natural, ephemeral wetland and compares hydrogeological properties of three natural and three constructed wetlands in DBNF. 30 PVC monitoring wells were installed in a natural ridgetop wetland in spring 2017. Horizontal and vertical soil heterogeneity were determined through slug tests and basic water chemistry sampling. To find soil permeability, 33 slug tests were administered, and hydraulic conductivity was calculated via the Bouwer-Rice method. Temperature (°C), dissolved oxygen (DO%), pH, and specific conductance (μS/cm) were measured and mapped to determine preferential groundwater flow patterns. Vertical heterogeneity was estimated by taking water chemistry measurements for six well water columns. Finally, slug tests were conducted and compared between three natural and three constructed wetlands. Warmer water emanated from the natural ridgetop wetland’s pool and followed a preferential flow path located on the aquifer’s surface. Permeability varies by three orders of magnitude (0.007 m/d to 7.594 m/d) for the natural ridgetop wetland. Permeability is generally lower in the artificial wetlands than the three natural ephemeral wetlands.