短语词组短语surface runoff 地表径流；地面迳流urban runoff 城市径流runoff coefficient 径流系数runoff generation [水文]产流river runoff 河川径流;径流量;河流径流量presidential runoff 总统决胜选举runoff cycle [水文]径流循环;迳流循环runoff change 径流变化 返回 runoff