Arinala has a bachelor degree in civil engineering (B.Sc.).  He holds a Master of Science (M.Sc.) degree in hydrogeology. During his master thesis, he studied the modelling and simulation of biogenic chloroform (trichloromethane) transportation in the unsaturated zone of a sandy porous aquifer.

Arinala works on parametric sensitivity analysis of lumped (GR4J, MORDOR10) and distributed (SWAT) hydrologic models. The main objective of his PhD research is to facilitate the tasks of model users by reducing the number of the parameters to be optimized through the identification of those model parameters which have the greatest influence on the variation of model outputs.