前言观测时间是水文测验中重要因素之一,无论在汛期水情传播中,水文分析研究中,时间都是不可缺少的。观测时间不准确,常常会引起分析与研究工作的很大困难,成果紊乱,规律错杂,使工作无法进行。此外,由于各地时间互不一致,也易造成洪水传播及防洪报汛工作的错误。因此,欲提高测验成果的价值,避免在工作中产生错误,对于掌握正确的观测与传报时间是不可不注意的。作者在工作中,常常看到水文站提出关于观测时间校正的问题。由于钟表时刻快慢不一,大多数水文 Preface The observation time is one of the important factors in the hydrological test. No matter in the hydrological analysis of flood season, the time is indispensable. Inaccurate observation time often leads to great difficulties in analysis and research work. The results are disorganized and the laws are complicated so that the work can not be carried out. In addition, due to inconsistencies in time and place, it is also likely to cause errors in the flood spreading and flood prevention work. Therefore, to increase the value of the test results and avoid mistakes in the work, it is indispensable to grasp the correct time for observation and presentation. At work, it is often the case that the hydrological station has raised questions about the correction of the observation time. As the clock time varies, most of the hydrological