This directory contains MATLAB routines for computing the thermal
conductivity (lambda) and heat capacity (c) of a soil.  Since thermal
diffusivity is simply K=lambda/c, you can also compute the thermal
diffusivity.  
 
Input variables:
 
rhob                  Bulk density of the soil (in g/cm^3)
cs                    Heat capacity of the soil particles typically
                      around 0.73 kJ/(kg K)
cw                    Heat capacity of the water (4.18 kJ/(kg K))
thetag                Gravimetric water content
thetav                Volumetric water content 
phim                  Volume fraction of minerals other than quartz
phiq                  Volume fraction of quartz
phis=phiq+phim        Volume fraction of soil particles
mc                    Clay mass fraction

Note that thetag and thetav are related by 
 
  rhow*thetav=rhob*thetag

where rhow is the density of water (1 g/cm^3).  

The functions are
 
  lambda            Computes thermal conductivity
  heatcap           Computes the heat capacity

The "plotlambdas" script plots the thermal conductivity for three
different soils over a range of water contents.  The "plotheatcap"
script plots the heat capacities of the same soils over a range
of water contents.
