modulus of drainage

例句：

1. 1. The engineer calculated the modulus of drainage for the new road.
   工程师计算了新道路的排水模数。
2. 2.The construction company needs to ensure that the modulus of drainage is within acceptable limits.
   建筑公司需要确保排水模数在可接受的范围内。
3. 3. The city has implemented measures to improve the modulus of drainage in order to prevent flooding during heavy rains.
   城市已经采取措施改善排水模数，以防止大雨期间发生洪水。