發送短信 : Time of concentration formulas for overland flow

  _  __     ___     ______      ___              
 | |/ //   / _ \\  |      \\   / _ \\    ____    
 | ' //   | / \ || |  --  //  / //\ \\  |    \\  
 | . \\   | \_/ || |  --  \\ |  ___  || | [] ||  
 |_|\_\\   \___//  |______// |_||  |_|| |  __//  
 `-` --`   `---`   `------`  `-`   `-`  |_|`-`   
                                        `-`