Spatiotemporal distribution analysis of extreme precipitation in the Huaihe River Basin based on continuity.

The Huaihe River Basin (HRB) is located in the climate transition zone between north and south of china, where cold and warm air flows are easily encountered, resulting in frequent extreme precipitation events occurred in this area. In this study, in order to extract the spatiotemporal distribution characteristics of extreme precipitation in the HRB, the optimal edge distribution functions were used to fit the precipitation series to obtain the extreme precipitation threshold, and then six indicators were used to describe the spatiotemporal distribution characteristics of extreme precipitation. The results show that the number of occurrences and the amount of precipitation in the HRB are generally greater in the southern part than in the northern part, but the intensity of precipitation in the eastern coastal areas is greater than in the inland areas. The Weibull function has the best fitting effect on both the precipitation and precipitation intensity series in the five zones of the HRB. As the cumulative probability increases, the area with the largest precipitation amount is Zone 1, and the area with the largest precipitation intensity is Zone 3. The spatial variation trends of extreme precipitation and intensity-based extreme precipitation in the HRB are roughly the same. The area with more extreme precipitation is in the southwest of the basin, while the area with higher precipitation intensity is on the eastern coast of the basin. The number of extreme precipitation occurrences has a decreasing trend in most of the basin, and the precipitation amount also has a decreasing trend, but the precipitation intensity has an increasing trend in the southern and northern parts of the basin. Both the start date and end date of extreme precipitation have an increasing trend, indicating that the occurrence time of extreme precipitation has a tendency to delay. This study can provide an important reference for the prevention of extreme precipitation disasters in the HRB. [ABSTRACT FROM AUTHOR]