Dear Sanghoon,
I thought of the issue for a while too.
In my mind, variability is a word to be used in broad sense, but
heterogeneity is one more specific. Dependent on the spatial context (known
spatial location or unknown), the two words convey different level of
content. Variability (variations of values) are actually spatial scale
dependent(study plot or area), but many studies usually don't require an
accurate record of spatial location (or pattern) of their sampling, rather,
more focus on changes of "central tendency" for their research goals. I
have used coefficient of variation (CV) and Cocran's C test to index
variability in my study. With accurate spatial location known, variability
can be well represented by heterogeneity, which can be indexed by a various
of methods (trend surface analysis, autocorrlation correlograms, kriging
maps).
In my recent publication we explored the within-plot variability and
contrasting spatial heterogeneity among three land uses.
Li J, Richter DD, Mendoza A, Heine P (2010) Effects of land-use history on
soil spatial heterogeneity of macro- and trace elements in the Southern
Piedmont USA. Geoderma 156:60-73
Hope it helps.
Thanks,
Jianwei
------
Jianwei Li, Ph.D
Postdoctoral Researcher
Department of Ecology and Evolutionary Biology
Kansas Biological Survey
University of Kansas
Lawrence, KS 66047
Email: j...@ku.edu
Office: 785-864-1564
Fax: 785-864-1534
--On Friday, May 28, 2010 6:17 PM -0400 Sanghoon Kang <sk...@ou.edu> wrote:
I was writing a paper discussing spatial heterogeneity of soil
measurements. At the moment, I became confused between the concept of
heterogeneity and variability. To me 'heterogeneity' contains 'spatial'
context,
and 'variability' has 'variations of values'. Thus 'heterogeneity of N'
means 'N concentrations are different at different sampling locations',
while 'variability of N' means simply 'variations of N concentration
without considering locations of sample'. Then in the context of
'spatial' it seem like they become indistinguishable. But I feel like
they are not exactly same. Any insight?
SANGHOON KANG.
