为探讨降雨对山丘区小流域洪峰模拟不确定性的影响,提高山丘区小流域洪水预报的精度,本文采用新安江水文模型在河南省山丘区小流域进行不同降雨误差输入条件下的径流模拟对比分析,并进一步探讨了考虑前期土壤干湿程度的降雨输入对洪峰模拟结果的影响及其变化趋势。研究结果表明：山丘区小流域洪峰模拟值的偏差随降雨输入误差的增加而增加,二者呈正相关；随着前期土壤由干到湿变化,对于相同的降雨输入误差,洪峰模拟偏差逐渐变小,且降雨输入偏大程度越大时,这种变小趋势越明显。

: In order to discuss the effect of rainfall on uncertainty of flood peak simulation in small-scale watershed in mountainous area and improve accuracy of prediction in there, the Xinanjiang model was chosen as the flood forecasting model in this paper to compare and analyze the runoff simulation under different inputs of rainfall deviation in small mountainous watersheds of Henan Province. It also discussed influence and rainfall input to flood peak simulation result under the condition of different preliminary soil dryness and wetness. The study result indicated: deviation of simulation value in small-scale watershed in mountainous area increases with increase of rainfall input deviation, the two presented positive correlation; with the preliminary changed of soil from dry to wet, the deviation of flood peak simulation was gradually getting smaller compared for the same rainfall input deviation, and the large degree of larger rainfall input is, the more obvious such smaller trend will be.