Hello Tejaswi

The problem is that the method that you are using doesn't fit for chemical
parameters, because those values could be from decimals to thousands. I Strongly
recommend you to use Krigging method, BUT using the appropiete variogram. The
best software could be SURFER or an Arcview extention for krigging (you can find
out in the internet).

Regards

Xavier COELLO-RUBIO
UNESCO-IHE
The Netherlands

Tejaswi <tejaswi_sh@...> wrote:
Hello members,
I am using ArcView 3.2a (demo version) to generate contour maps for
different physico chemical parameters of groundwater samples. The contours are
being generated by making use of the point interpolation method. While
generating these maps from the database created, i am encountering this problem.
The problem is, many of the contours are displaying negative values. There are
no negative values in the database and moreover no field in the database is left
blank. The minimum value for any of the parametes is zero. Eventhough for some
of the parameters there are not even zero values, the negative contour values
are being displayed.
Any one knowing the solution for this problem is kindly requested to help
me in this regard.

Thanks in advance

Tejaswi