特征水位是防汛预警决策的重要依据。近年来，淮河三河尖水位站经常出现大范围长历时的水位超警，现有的特征水位已逐渐不能适应当前防汛工作需要。采用上下游水面线分析水力学法水位过程线对比分析和最高水位年频次分析等方法分别得出相应的特征水位，综合考虑堤防超高特征水位确定原则以及抗洪抢险联动性等因素，提出更为合理可行的特征水位，最后对三河尖两岸淹没情况和上游圩区进行影响分析。结果表明：特征水位调整对三河尖两岸及上游圩区堤防影响不大；三河尖水位站原警戒水位和保证水位过低，应适当提高。

The characteristic water level is an important basis for flood control and early warning decision-making. In recent years, large-scale and long-lasting water level over-alarms have frequently occurred at the Sanhejian Water Level Station of the Huaihe River. The existing characteristic water level has gradually been unable to meet the needs of current flood control work. This paper uses upstream and downstream water surface line analysis, hydraulics method, water level process line comparison analysis, and highest water level annual frequency analysis to obtain the corresponding characteristic water levels, comprehensively considering factors such as the superelevation of the embankment, the principle of determining the characteristic water level, and the linkage of flood fighting and emergency rescue. A more reasonable and feasible characteristic water level is put forward. Finally, the impact analysis of the flooding situation on both banks of Sanhejian and the upstream polder area is carried out. The results show that the characteristic water level adjustment has little effect on the dikes along the banks of Sanhejian and the upstream polder; the original warning water level and guaranteed water level of the Sanhejian Water Level Station is too low and should be appropriately raised.