Hi list,
this is a rather theoretical question, so sorry if it is not very
appropriate for this list, but with a bit of luck someone may
feel
challenged to reply.
I am looking for the correct procedure to average spatially
interpolated
data over an area. Specifically, I used kriging to interpolate
point
rainfall over a grid covering a catchment and now I want to
estimate the
average rainfall over the catchment, including the uncertainty on
the
estimation.
Obviously, taking just the mean and the variance of all the grid
cell values doesn't work because it does not take into account
spatial
correlation and thus underestimates the uncertainty.
So what is/are the best method(s)? Suggestions on how to
implement them in
R are very welcome, as well as suggestions for literature if the
answer
would turn out to be more complicate than I imagined.
Many thanks!
Wouter Buytaert
Lancaster University