Method for calculating ecological flow of region without actually measured runoff data

The invention belongs to the technical field of drainage basin ecological environment management, and particularly relates to a method for calculating the ecological flow of a region without actually measured runoff data, and the method comprises the following steps: 1, collecting day-by-day rainfall data and rainfall station geographic position coordinates of rainfall stations in a research drainage basin and around the drainage basin; 2, dividing the research basin into unit grids according to calculation precision requirements; step 3, year-by-year rainfall data of each rainfall station is spread to each unit grid through an inverse distance weighted leveling method; 4, calculating an annual rainfall variation coefficient Cv; 5, calculating the average flow R of many years; 6, determining an annual runoff variation coefficient CvR and a deviation coefficient CsR; and 7, solving the flow of the N% guarantee rate. The invention provides the method for calculating the ecological flow of the region without act