Rainfall, temperature and evaporation trends in the Fitzroy Basin, Queensland, Australia

Rainfall, temperature and evaporation govern the regional hydrologic cycle. There are several studies that have analysed the changing pattern of climatic variables at a global scale as well as regional scale in Australia. It is suggested from the recent studies that trend analysis of climatic variables should be performed at the catchment scale rather than at a global or regional scale as the trends and their effects may vary from one location to another. Fitzroy Basin is the second largest coastal river system in Australia. No study at the catchment scale is found to exist in this important catchment. This study analysed the rainfall, maximum and minimum temperature and evaporation trend at 31 measuring stations within the catchment for the period 1954 to 2010. The most widely nonparametric test, Mann-Kendall, has been used here to detect the trend. In summer, an overall insignificant decreasing trend of rainfall has been found in most of the stations whereas no trend has found for winter rainfall. In contrast increasing trend has been found in the maximum temperature, minimum temperature and evaporation station. Moreover to get a clear idea, seasonal time series plots of rainfall data and monthly percentage of annual average rainfall cycle has been presented. Besides annual anomalies for maximum and minimum temperature has been shown here.