Method for measuring riverway flow based on aerial-photography unmanned aerial vehicle

The invention discloses a method for measuring riverway flow based on an aerial-photography unmanned aerial vehicle. The method comprises the following steps that a buoy cross section is established; water depth is measured; the aerial-photography unmanned aerial vehicle is erected in a middle cross section; a buoy is put; when the put buoy passes through an upper cross section, the middle cross section and a lower cross section, the aerial-photography unmanned aerial vehicle is utilized to perform continuous photography according to the operating process of buoy putting, upper cross section photography, middle cross section photography and lower cross section photography; when the buoy is read and the flow is measured, a distance from a starting point and virtual flow are calculated. By adopting the method, the flow measuring time is greatly shortened, the efficiency of measuring flood discharge of a buoy method is greatly improved, accordingly the timeliness of flow measurement is wholly improved, and accur