Hi
I am currently crrying out water management studies in a hard rock
watershed (1000 sq.km) in Tamil Nadu and needs to compute the non-
committed surplus runoff available for my studies. As there are no
gauging stations, I have to use empirical methods for runoff
computation. I've computed the monsoon rainfall for the raingauge
stations using Theissen Polygon method and was planning to use
Strang's tables for runoff estimation. However, one of my polygons
have normal rainfall > 1000 mm. (hilly area, mostly) and I find that
Strang's Tables are available only upt 600 mm rainfall. Can anybody
tell me whether it is proper to extrapolate the curves graphically
using the available data ? If not, what other methods could I use?
Curve Number method is out of question as I don't have enough data
for that!

Recently I came across a software namely 'WADI' by ENEX Corporation,
which has a subroutine for runoff estimation. However, I am not able
to find any information or user manual of the program ( for the
theoritical background of the equations used etc.)anywhere. Any
suggestions.

Thanking you in advance

regards

Nandakumar