Eleventh International Conference on Climate Change: Impacts & Responses

Abstract

Climate change has already been experienced in Australia with recent more frequent hot weather, fewer cold days, shifting rainfall patterns. Thus climate change would influence the hydrologic cycle by changing rainfall intensity, frequency, and spatial and temporal distribution in this region. This study aims to find out change in rainfall frequency at five selected rainfall stations in Melbourn, Australia. Two widely used probability distribution functions, Generalized Rare Value (GEV) and Log-Pearson type III (LP3) distributions are adopted in this study for frequency analysis using annual maximum rainfall data with help of FLIKE software. The annual maximum rainfall data at each of these stations were sub-sets: 1889-1952, 1953-2016, 1889-1986 and 1987-2016 to observe changes in rainfall frequency in previous and recent period. Recent periods (1953-2016 & 1987-2016) were compared to respective past observation periods (1889-1952 & 1889-1986) for each of the stations. GEV always produced higher values than LP3 for any Annual Exceedance Probability. In most cases, recent period (1953-2016) had higher values than respective past. During very recent period (1987-2016), it had higher rainfall at Lovely Banks and Melbourne Airport but had reduced magnitudes for frequent storms at Essendon Airport and Narre Warren North stations. On the other hand, Flemington Racecourse station had lower rainfall in very recent period for all AEPs compared to past. Thus, the popular proclamation in the arena of climate change of rainfall incidents are becoming rare in this area is not entirely accurate; rather it has spatial variation at regional scale.