Spatial and temporal characteristics of rain-spells in New Zealand

The present study analyzes the spatial and temporal distributions of rain-spells and their characteristics in New Zealand. Various rain-spell parameters such as their average number (NRS), average yield (RSY), average intensity (RSI), and average duration (RSD) and the inter-correlations among all variables are analyzed. Intra-annual variability and the rain-spell characteristics during dry and wet years are presented. Daily rainfall totals from 19 stations on both islands for the period 1965–2017 were used. Rain-spell characteristics were defined using a daily rainfall threshold (DRT) of 1.0 mm. Various functions were fitted to represent the relationship between rain-spell characteristics and their duration-RSD. Dry and wet years were defined according to their standardized departures from the long-term mean: