Modelling of Major Flood Arrivals on Chinese Rivers by Switch-time Processes

Nowadays, there is a considerable flood risk in China is. A brief description of major floods on Yangtze River and Huang He River is given. Both big Chinese rivers have long records of floods with severe life and property damages. Quantification of the stochastic behaviour of the largest floods is a key task in the risk assessment and mitigation. An exponential distribution of the time intervals between consecutive floods is assumed in classical study of inter-arrival times of floods. An approach for modelling of flood arrivals on both Chinese rivers by switch-time (ST) processes is proposed. These ST distributions can be considered as distributions of sums of random number exponentially distributed random variables. The proposed model specifies explicitly times of occurrence not only of floods but also of higher risk of potential floods. This approach could be useful for making prognoses of floods and for analysing changes in hydrologic behaviour of rivers.