 The study aims to quantify environmental flow requirements, EFRs, for freshwater ecosystems. EFRs are calculated using five different methods, including the variable monthly flow method and the Q90 underscore Q50 method. These methods take into account intranual variability by allocating EFRs with a percentage of mean monthly flow or annual flow quantiles depending on the flow season. The results showed that more water is needed for environmental flows during low flow periods compared to high flow periods. The test man VMF methods showed the highest correlation with locally calculated EFRs, while the tenant Q90 underscore Q50 and smocked in methods were less accurate. The global applicability of the five methods was tested using a hydrological model and the calculated global annual EFRs for fair ecological conditions represent between 25 and 46 percent of mean annual flow. Variable flow regimes have lower EFRs than stable tropical regimes. This article was authored by A.V. Pastor, F. Ludwig, H. Beeman's, and others. We are article.tv, links in the description below.