明渠和管道的糙率系数是很好推求的,但耕地和森林的糙率就不那么容易了。在耕地漫流情况下,曼宁糙率系数(n)是很重要的。因为它是好几种模型的主要输入参数,如运动波模型、无惯性模型和几个相似模型或流域水文学等。 曼宁糙率值一般是在实测径流过程线(或灌溉推进曲线)中选配无惯性模型或运动波模型中求得。然而,这种计算方法要求作繁杂的计算。 Roughness coefficient of open channel and pipeline is well deduced, but the roughness of cultivated land and forest is not so easy. Manning roughness coefficient (n) is very important in the case of arable land runoff. Because it is the main input parameter for several models, such as the motion wave model, the inertial model and several similar models or hydrological hydrology. The Manning roughness value is generally obtained from an inertial or motion wave model selected from measured runoff curves (or irrigation propulsion curves). However, this method of calculation requires complicated calculations.