The geographical distribution of flood disasters in China is very wide, and the flood pattern in historical period shows east-west differentiation. The frequency of disasters in the eastern region is higher than that in the western region, especially in Liaodong Peninsula and the plain in the middle and lower reaches of Liaohe River, as well as in the eastern region along a series of mountains such as Yanshan Mountain, Taihang Mountain, Funiu Mountain, Wushan Mountain and Xuefeng Mountain, and in the middle and lower reaches of Xijiang River south of Nanling Mountain. These areas are located in the middle and lower reaches of major rivers in China, affected by meteorological factors such as westerlies and tropical cyclones, with frequent rainstorms and large-scale floods.
China is located in the east of Eurasia, on the west coast of the Pacific Ocean, bordering the Indian Ocean in the southwest, with high terrain in the west and low terrain in the east, and most of it is in the middle and high latitudes. Affected by geographical location, topographical factors and climate, most parts of the country are threatened by flood disasters, and floods may occur all year round. In winter, ice flood disasters in northern China mainly occur in the lower reaches of Ningmeng, the main stream of the Yellow River, and Harbin section of Songhua River. During the freeze-thaw period, a large number of ice plugs form ice plugs or ice dams, which leads to high water level and flood. Floods may also occur in some areas in the south. In spring, the rainstorm in the first flood season in South China mainly causes floods, and there will be floods caused by snowmelt floods in the western region. Summer and autumn are the seasons with the most floods in a year, with a wide range, long duration and severe disasters. The floods in seven major rivers occur in summer and autumn.