An Empirical Model for Estimating Soil Thermal Diffusivity from Texture, Bulk Density, and Degree of Saturation
Abstract
Soil thermal diffusivity κ is an essential parameter for studying surface and subsurface heat transfer and temperature changes. It is well understood that κ mainly varies with soil texture, water content θ, and bulk density ρb, but few models are available to accurately quantify the relationship. In this study, an empirical model is developed for estimating κ from soil particle size distribution, ρb, and degree of water saturation Sr. The model parameters are determined by fitting the proposed equations to heat-pulse κ data for eight soils covering wide ranges of texture, ρb, and Sr. Independent evaluations with published κ data show that the new model describes the κ(Sr) relationship accurately, with root-mean-square errors less than 0.75 × 10−7 m2 s−1. The proposed κ(Sr) model also describes the responses of κ to ρb changes accurately in both laboratory and field conditions. The new model is also used successfully for predicting near-surface soil temperature dynamics using the harmonic method. The results suggest that this model provides useful estimates of κ from Sr, ρb, and soil texture.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 01, 2018
- Source ID
- 10.1175/jhm-d-17-0131.1
Entities
People
- Robert Horton
- Tusheng Ren
- Xiaoting Xie
- Yili Lu
Organizations
- Army Research Office
- China Postdoctoral Science Foundation
- Iowa State University
- National Natural Science Foundation of China
- National Science Foundation