Examination of Changes in the Characteristics of Precipitation in the West Coast Florida

Abstract:

Examining potential changes exhibited in regional precipitation is not only the key to understand possible changes in the whole hydrologic processes, it also has practical meanings for water resources management. This study aims to investigate possible changes in precipitation at multiple time scales using observed data and examine the driving force of such changes in the West coast Florida. Rainfall stations with a record of at least 70 years and daily data availability great than 90% are identified for analyses. Different aspects of precipitation properties are examined, including within-year distribution of total rainfall amount, onset and demise of summer rainy season, no-rainfall days in summer rainy season, and extreme daily precipitation. The first three are chosen due to the importance of filling up within-year reservoirs for water supply systems in the study region. Extreme daily precipitation is modeled using extreme value distribution, with the assistance of extRemes package in R. Potential changes in the extreme precipitation pattern is incorporated in a non-stationary modeling framework. Possible connections between ocean-atmospheric climate index and changes in precipitation are investigated. Implications of changes in such precipitation properties on water supply systems are also discussed.