Modeling of Carbon Dioxide Transport and Production in Soil 2. Parameter Selection, Sensitivity Analysis, and Comparison of Model Predictions to Field Data

Authors

Donald L. Suarez, USDA-ARSFollow
Jiří Šimůnek, USDA-ARS

Date of this Version

1993

Comments

Published in Water Resources Research, Vol. 29, No. 2, Pages 499-513, February 1993

Abstract

In paper 1 of this two-paper series (Šimůnek and Suarez, this issue) we presented a description of the numerical model, SOILCO2, for CO₂ transport and production in the unsaturated zone. In paper 2 the model sensitivity to various parameters is evaluated by both steady state and trasient simulations, with a range in the parameter values typically found under field conditions. We also select parameter values for optimal plant and microbial CO₂ production and production dependence on temperature, water content, osmotic potential and gas composition for plant and microbial respiration, all based on literature review. The predictive capabilities of the SOILCO2 model are evaluated by comparing model simulations to published field data from Missouri for three different cops and two growing seasons under transient conditions as well as a data set collected in Riverside, California, under relatively constant water content at depth. The model provided good prediction of the CO₂ flux to the atmosphere as well as the concentrations in the root zone for all data sets.