城西试验流域水文特性及水文过程模拟

水文试验是认识水文规律的重要基础工作。根据我国东部低山丘陵区城西试验流域的实测资料,分析不同尺度降雨径流之间的响应关系,再利用新安江流域水文模型进行径流模拟,进一步探讨该模型在我国东部低山丘陵区的适用性。结果表明:在试验流域空间尺度(几十平方公里)的暴雨洪水过程中,洪水峰现时间一般滞后雨峰3～4 h;场次和月尺度上的降雨径流具有较好的正相关关系;在日尺度上,降雨径流关系散乱,以10和70 mm降雨量为阈值呈U型分布; 3种时间尺度上,径流均受到前期退水过程的影响,其中,时间尺度越短,受前期退水过程的影响越显著;新安江流域水文模型在我国东部低山丘陵区具有较好的水文模拟能力,且月尺度水文过程的模拟效果优于日尺度,对天然流域的模拟效果优于人类活动扰动的流域。

Hydrological characteristics and process simulation of Chengxi experimental watershed

Hydrology experiment is of importance to understand hydrological laws. According to the observed data of Chengxi experimental watershed located in the eastern low hilly area of China, responses of runoff to rainfall variation at different scales were analyzed. The feasibility of the Xin''anjiang model to low hilly area of China was verified using the hydrological simulation approach. The results showed that: At experimental watershed scale (tens of square kilometers), discharge peak time usually lags 3-4 hours from storm peak time. Runoff highly correlated to rainfall at both event-and month-scale whereas the weak correlation was found at daily-scale, the scatter points of daily runoff to rainfall presented a U-type distribution with rainfall thresholds of approximately 10 mm and 70 mm. Runoff was extensively influenced by antecedent hydrological recession at three time scales, with higher influence at shorter scale. The Xin''anjiang model can generally reproduce hydrological process of the eastern low hilly area with a better performance at monthly scale, and the simulation of natural watershed is better than that of human disturbed watershed.