Picket plot only crossplot to define our waterzone from Rw and convert it to salinity (a, m & n has been defined before from core data). If you want to define a, m & n exponent from picket plot its was only seen based on gradient of our data distribution.
Buckle number made by buckle to identify characteristic of reservoir properties based on porosity vs swirr. In normal condition m & n value will increase on low quality reservoir and characterized by high value of KBuckle. Attached papers for Kbuckle.