High-Precision Measurements of Wetland Sediment Elevation: II. The Rod Surface Elevation Table

ABSTRACT A new high-precision device for measuring sediment elevation in emergent and shallow water wetland systems is described. The rod surface-elevation table (RSET) is a balanced, lightweight mechanical leveling device that attaches to both shallow ( 1 m in order to be stable. The pipe is driven to refusal but typically to a depth shallower than the rod bench mark because of greater surface resistance of the pipe. Thus, the RSET makes it possible to partition change in sediment elevation over shallower (e.g., the root zone) and deeper depths of the sediment profile than is possible with the SET. The confidence intervals for the height of an individual pin measured by two different operators with the RSET under laboratory conditions were ± 1.0 and ± 1.5 mm. Under field conditions, confidence intervals for the measured height of an individual pin ranged from ± 1.3 mm in a mangrove forest up to ± 4.3 mm in a salt marsh.