The investigation of bed topography downstream of culverts is very important. Since bed topography goes through extreme changes through time, this study investigated the temporal evaluations of bed topography. Also, the bed level downstream of culverts, as one of effective parameters in topography in different time spans, was investigated. One of the most important findings of the study is that with increasing the experiment time and approaching the equilibrium moment, the change percentage of the maximum scour depth decreased. Also with changes to and decrease in the bed level downstream of the culvert, the change percentage of the depth scour decreased. Another salient finding of this study was that the maximum scour over the beginning durations of the tests in case of equal downstream level and culvert bed level was approximately equal to the maximum scour in cases where the downstream bed level differed from the culvert bed level by 0.067 and 0.13 times the culvert mouth width.

涵洞下游河床地形调查十分重要。由于河床地形随着时间的推移会经历极大的变化，因此本研究调查了河床地形的时间评估。此外，还对涵洞下游的床位作为不同时间段地形的有效参数之一进行了研究。该研究最重要的发现之一是，随着实验时间的增加和接近平衡时刻，最大冲刷深度的变化百分比减小。此外，随着涵洞下游河床水位的变化和降低，深度冲刷的变化百分比也降低。这项研究的另一个显着发现是，在下游水位和涵洞床位相等的情况下，测试开始持续时间的最大冲刷大约等于下游床位与涵洞床位相差 0.067 的情况下的最大冲刷。涵口宽度的0.13倍。