Peb hydrodynamic tsis siv neeg dej nyab teeb meem yog tsim rau hauv nroog underground qhov chaw (xws li underground constructions, underground garage, subway station, underground shop, street passage and underground pipe gallery, etc.) thiab kev nkag thiab tawm ntawm cov tsev qis qis los yog thaj chaw hauv av, thiab kev nkag thiab tawm ntawm substations thiab faib chav, uas tuaj yeem raug dej nyab los ntawm cov dej hauv av.
