Evaluating long-term trends in annual and seasonal precipitation in Taiwan

This work studies long-term rainfall variations in Taiwan and provides local climate change analyses to global climate change. Around a century of rainfall data from 33 rain-gauges populate the database used herein. Statistical tests, such as cumulative deviations, Mann-Whitney-Pettitt statistics and the Kruskal-Wallis test, were first employed to determine whether annual rainfall series exhibit any regular trend. Analytical results indicate that the annual rainfall has increased in northern Taiwan, declined in central and southern Taiwan, and exhibited no clear tendency in Eastern Taiwan. Almost all of these rainfall series changed significantly around 1960, which date divides historical rainfall series into two sample groups. This change in the seasonal rainfall was further investigated.