洪涝灾害是海河流域最严重的自然灾害之一，对基础设施、电力、交通、农业等都具有巨大破坏性，一直以来受到各防汛决策部门的重视和关注。而海河流域西部、北部为山区高原，东南部为华北平原，地势平缓，流域山地与平原间丘陵过渡带较短，河道源短流急，洪水流速大，传播时间短，从山区降雨到河道出口出现洪水，最长不超过1~2天，短的仅几个小时，使得流域洪水具有预见期短且突发性强的特性。暴雨是造成洪灾最直接最根本的原因，本文应用水文、气象资料相结合来筛选海河流域历史致洪暴雨个例并进行特征分析的研究，具体采用海河流域水文监测资料、国家气象站日降水资料和ERA5全球再分析资料，依据海河水利委员会《海河流域设计洪水修订推荐成果表》中规定的频率和相应的洪峰流量设计值，按照1952-2020年海河流域各水文站日最大流量数据筛选出近70年海河流域的历史特大洪水、大洪水和中等洪水过程，并进一步根据发生洪水的水文站点和时间间隔将洪水分为区域性洪水和局地性洪水。通过分析洪水发生次数随时间变化和海河流域不同河系历史洪水发生频率分布得到海河流域海河流域历史洪水时空变化特征。结果表明：近 70年流域的特大洪水、大洪水和中等洪水均出现在 7月和 8月，洪水发生频数存在两个峰值点，这与夏季风的移动和强度变化有关；空间上流域洪水地理分布呈东北-西南走向，呈现出南多北少、西多东少的特点，其与流域地形密切相关，发源地为山区背风坡的河系，河流源远流长，汇水面积大、水系集中，比较容易控制，而发源地为迎风坡的河系，支流分散、源短流急，突发性强，较难控制，且流域太行山、燕山迎风区也是大暴雨的集中地带，使得河系陡涨抖落、洪量集中、洪峰高、历史短的形式出现，这导致流域中南部是区域性特大洪水频发区。进一步对 1952-2020年海河流域历史洪水分布及降水距平年际变化进行统计分析，发现 80%以上的洪水个例和 100%的区域性洪水均发生在降水偏多年份，历史洪水次数的年代际波动较大，呈“多-少-多-少”阶段式变化特征，与华北夏季降水的变化特征相符。最后，本文通过分析致洪暴雨历史个例发生当日及过去 4天的天气图，将海河流域（111°E-121°E，34°N-43°N）作为关键区，分析关键区暴雨的影响系统和发生机制，将海河流域致洪暴雨大致分为5种天气型，分别为：北上台风型、东北冷涡+西南涡型、低涡型、高空槽型和蒙古冷涡型，其中海河流域致洪暴雨受台风影响占比最高，为42. 4%，其次是冷涡和低涡，占比分别为27. 3%和15. 2%。而流域发生过的3次区域性特大洪水也均受台风和低涡影响。

Flood disasters are among the most serious natural disasters in the Haihe River Basin，inflicting substantial damage on infrastructure，electricity，transportation，agriculture，and other critical sectors. It has always been given great attention and concern by various flood control decision-making departments. The western and northern parts of the Haihe River Basin are mountainous and plateaus，while the southeastern part is the North China Plain with gentle terrain. The transition zone between the mountainous area and the plain is relatively short，and the river channels have short sources，rapid flow，and large flood flow velocity. The propagation time of floods is short，with the longest time from rainfall in the mountainous area to the occurrence of floods at the river outlet not exceeding 1~2 days，and the shortest time being only a few hours. This makes floods in the basin characterized by a short lead time and strong suddenness. Heavy rain is the most direct and fundamental cause of flood disasters. In this study，hydrological and meteorological data are used to select and analyze the characteristics of historical flood-causing rainstorms in the Haihe River basin. Based on hydrological monitoring data in the Haihe River Basin，daily precipitation data from national meteorological stations，and ERA5 global reanalysis data，refered to the recommended design flood revision results and corresponding peak discharge design values specified in the Haihe River Water Conservancy Commission's "Recommended Results Table of Design Flood Re‐ vision in the Haihe River Basin"，historical extreme floods，major floods，and moderate floods in the Haihe River Basin since 1952 were selected and analyzed. According to the number of hydrological stations with flood and the time interval between flood occurrences，the flood can be divided into regional flood and local flood. Analy‐ sis on the frequency of flood with time and the frequency distribution of historical flood in different river systems，The temporal and spatial characteristics of historical flood in Haihe River Basin are obtained. The results indicate that extreme floods，major floods，and moderate floods in the basin over the past 70 years all occurred in July and August，and there are two peak points in the frequency of flood occurrences，which is related to the movement and intensity changes of the summer monsoon climate；Geographically，the occurrence of floods in the basin shows a northeast-southwest trend，with the characteristics of more occurrences in the south and fewer in the north，and more occurrences in the west and fewer in the east. Analysis of the basin's topographical features shows that the river systems on the leeward slopes in the mountainous areas，with long river sources and large drainage areas，are relatively easy to control，while the river systems on the windward slopes have dispersed tributaries，short sources，rapid flow，and strong suddenness，making them relatively difficult to control. Moreover，the windward areas of the Taihang Mountains and the Yan Mountains are also concentrated areas of heavy rain，leading to sharp rises in river levels，concentrated flood volumes，high flood peaks，and short historical durations. Therefore，extremely large floods are most likely to occur in the central and southern parts of the basin. Furthermore，statistical analysis on the historical flood distribution and interannual variation of precipitation anomaly in the Haihe River Basin from 1952 to 2020 shows that over 80% of individual flood events and 100% of regional floods occurred in years with above-average precipitation. The inter-decadal fluctuations in the number of historical floods exhibit a "more-less-more-less" stage-wise characteristic，which is consistent with the characteristics of summer precipitation changes in North China. Finally，based on the analysis of the weather chart on the day and the past 4 days of the extreme rainfall events causing floods occurrence，selected Haihe River Basin（111° E-121° E，34° N-43° N）as a key area，with analyzing the influencing system and occurrence mechanism of the heavy rain in the key area，the extreme rainfall events causing floods in the Haihe River Basin can be roughly classified into five synoptic patterns：northward typhoon pattern，northeast cold vortex + south‐ west vortex pattern，low vortex pattern，upper-level trough pattern，and Mongolian cold vortex pattern. Among them，the proportion of extreme rainfall events caused by typhoons in the Haihe River Basin is the highest，ac‐ counting for 42. 4%，followed by cold vortices and low vortices，accounting for 27. 3% and 15. 2% respectively. The three regional extreme floods that occurred in the basin were also influenced by typhoons and low vortices.