在进行标准海塘工程初步设计时 ,通常需要分析在河段江道的不利冲刷高程值 ,给海塘整体抗滑稳定计算条件组合提供依据。目前人们缺乏较好的分析手段 ,通常借用水文统计方法加以解决。由于受到江道地形测量的时间、间隔次数及来水来沙等因素的影响 ,一般很难获得冲刷最深的地形资料 ,往往难以统计。但是 ,当年内测次较多 ,并有汛期的地形测次 ,则可以取年内几次测图中冲刷最深值作样本 ,进行统计分析。这种方法仅适用于江道冲淤只受水动力条件控制的情形 ,对于床底下卧抗冲能力极强的地层 (如砂砾石层 ) ,江道的不利冲刷高程仅受地质条件控制。通过对钱塘江闻家堰河段水沙条件、河床地质构成、实测地形资料等综合分析 ,证明以上观点 In the preliminary design of standard seawall project, it is usually necessary to analyze the unfavorable flushing elevation value of the river course in the river section, and provide the basis for the combination of the antiskid stability calculation conditions of the seawall. At present, people lack a good analytical means, often using hydrological statistical methods to solve them. Due to the terrain measurement of the river, the number of intervals and water coming and going sand and other factors, it is generally difficult to obtain the most washed topographic data, often difficult to statistics. However, when there are more test times in a year and the topography of the flood season is measured, the deepest values ​​scoured in several times during the year can be taken as samples for statistical analysis. This method is only applicable to the case that the erosion and deposition of the riverway is controlled only by the hydrodynamic conditions. For the formations with extremely strong impact resistance under the bed (such as sand and gravel layer), the adverse erosion elevation of the riverway is only controlled by the geological conditions. Through a comprehensive analysis of water and sediment conditions, river bed geological composition and measured terrain data at Wenjiayan section of Qiantang River, it is proved that the above points