Monthly and seasonal rainfall (1963–2017) for a typhoon-influenced area in a Chinese karst basin

Abstract. Under the dual influence of global warming and typhoon weather, the characteristics of monthly and seasonal rainfall become more complicated and extreme, leading to more frequent rainfall and flood disasters. The objective of this study is to propose a framework for analysing the characteristics of rainfall and its correlation with typhoons. The proposed framework consists of an analysis of inner-annual distribution, inter-annual variation as well as correlation between rainfall and typhoons. Especially, a DVM method is proposed to compute the rationality and reliability of the abrupt change time analysis. Finally, the proposed framework was successfully implemented using a 55-year time series (1963–2017) of rainfall data recorded by 12 rain gauges in Chengbi River Basin (South China).The results are as follows. (1) The relative variability of monthly rainfall is relatively large (above 30 %), and the rainfall tends to be centralized, and is mainly concentrated in July. (2) The monthly average rainfall is relatively stable, the seasonal rainfall decreases in spring and summer, while increases in autumn and winter. The abrupt change occurred during 1980s–1990s.The main periods of rainfall in summer and winter are shorter than those in spring and autumn. (3) The typhoon-caused rain is the main factor affecting the summer and autumn rainfall while the number of typhoons has the least influence. It is suggested that the impact of typhoon should be taken into consideration in the modelling of spatial and temporal evolution of hazardous rainfall evens and their social hazard assessment for a typhoon-influenced area .Besides, preventive measures should be strengthened for flood and waterlogging disasters and that the reservoir should be operated at different FLWLs during different flood sub seasons in Chengbi River Basin.