【摘要】 曼宁糙率系数是描述地表水流运动的重要参数之一，但目前对于特定地块表面糙率的确定尚没有一种理想的方法。本文提出了一种根据田间水流推进资料来计算曼宁糙率的新方法。该方法以水量平衡原理为基础，用迭代法求解。经在不同地区、不同土壤类型和地面状况的田间观测数据验证，结果令人满意。更多还原

【Abstract】 Manming′s roughness coefficent is one of the most important parameters for describing movement of water flow on the ground.However it is not well established to determine surface roughness value in a particular field situation of surface irrigation.In this paper the method for calculating Manning′s roughness coefficient is presented based on the law of water balance and solved by iteration.The result is satisfied via testing with the field data obtained in different regions and various soil type and situation of filed surface.更多还原