Of note, I bumped into an interesting article in the RUSI journal discussing "intensity" and critiquing its utility.

Christopher Bellamy (1998): If you cant stand the heat ... new concepts of conflict intensity, The RUSI Journal, 143:1, 25-31

You're institution should allow you online access to the RUSI archives through informaworld. If not, PM me an email address and I'll send you a copy if you wish.