Exercises

The exercises in this section provide an opportunity for readers to explore some common activities for estimating water, solute, and heat flow parameters and fluxes in peat.

A summary of each exercise follows.

1. Exercise 1 invovles calculating hydraulic conductivity in peat usin the method of Hvorslev (1951) and data from a slug test. Two examples are provided. The first one requires a standard solution for a piezometer response common in porous media. The second example is for a response showing strong evidence of peat compressibility, which requires manual adjustment of the bail-test response curve to force the solution to fit the tail of the curve.
2. Exercise 2 estimates the flow of groundwater and a reactive solute from a peatland to a stream channel, illustrating that the decrease of K_sat with depth causes flux to be strongly dependent on the water table position. Depth-dependent values of K_sat, porosity (𝜙_t), mobile porosity (𝜙_mob), bulk density (ρ_b), distribution coefficient that controls solute retardation (R_f), are used to determine the solute flux.
3. Exercise 3 illustrates the importance of accounting for the character of the K_sat distribution, by posing a question similar to Exercise 2 with a more dramatic decrease in K_sat with depth.
4. Exercise 4 evaluates the change in thermal properties of a peat soil as it thaws, transitioning from saturated and frozen, to saturated and unfrozen, and then to unsaturated and unfrozen. The purpose is to illustrate how this affects heat flow in to and out of the ground.
5. Exercise 5 demonstrates the impact of changing soil water content on permafrost thaw which creates a feedback loop in peatland systems that promotes permafrost loss.