Simulating soil water dynamics in a cutover bog

Abstract

A simulation model flow in cutover peat systems (FLOCOPS) was developed to improve the current understanding of the hydrology of cutover peatlands and the water management programs designed to restore them. FLOCOPS considers temporal variability in peat bulk density, shrinkage character and θ-Ψ (soil moisture-pressure head) relationships, volume changes due to compression, and changes to saturated hydraulic conductivity (KS) and saturated volumetric soil moisture (θS). FLOCOPS was evaluated by comparing simulated and observed 1998-1999 trends in elevation change (thickness of peat deposit), water table, θ, and Ψ. FLOCOPS effectively represented observed trends in elevation change, θ, and Ψ. A sensitivity analysis indicated that FLOCOPS was most sensitive to the retention, storage, and consolidation characteristics of the peat. Volume changes reduced hydrological variability, whereas low water retentivity and high water storage helped maintain high and stable θ, Ψ, and water table position. The sensitivity of the peat system's hydrology to changes in pore structure suggests that minimizing changes to the peat's characteristic pore structure during extraction and subsequent abandonment of the peatland will result in significantly more favorable hydrological conditions for bog restoration.