Regional Maximum Annual Rainfall Estimates Using TL-moment and LQ-moment: A Comparative Case Study for North East India

Abstract

Rainfall data of the North East region of India has been considered for selecting the best fit model for rainfall frequency analysis. The five extreme probability distributions, namely Generalized extreme value (GEV), Generalized Logistic (GLO), Pearson type 3 (PE3), Generalized Log normal (GLO) and Generalized Pareto (GPA) distributions have been fitted using LQ-moment. Also three probability distributions namely Generalized extreme value (GEV), Generalized Logistic(GLO) and Generalized Pareto (GPA) distributions have been fitted using TL-moment. Both TL-moment and LQ-moment analysis show that GPA distribution is the best fitting distribution for the North Eastern Region. Relative root mean square error (RRMSE) and RBIAS are employed to compare between the results found from TL-moment and LQ-moment analysis. It is found that the TL-moment method is significantly more efficient than LQ-moment for maximum rainfall estimates of North East India. The rainfall frequency model for the region has been developed by using the identified robust distribution for the region.