[Npsource-cbpmodel] P53 Installation on Ubuntu 16.04

[ather a. <ath...@ya...>]

Hi everyone
I am trying to install P5.3 watershed model on my machine with Ubuntu 16.04 by following readme file. The point 3b o 'readme' says me to execute 'compile_all.csh' script. When I execute it from terminal, I get following errorMANPATH: Variable not defined. 
How can I fix this error?
Regards,Ather Abbas