The article proposes a new method for assessing the water resources of river basins. The essence of the proposed assessment with Runoff Coefficients Method (RCM) is the principle of estimating river water resources using runoff coefficients that take into account the influence of complex runoff-forming factors. Runoff coefficients are values that reflect the level of atmospheric precipitation formation into surface runoff under specific physical-geographical conditions. The main goal of applying new method was to transform the inter-component natural regularities into a quantitative form and use this approach to estimate the water resources of the territory. Research using the RCM method is carried out based on the principle of “maximum information, minimum dependence”. Thus, the assessment of water resources is fulfilled more efficiently and reliably by taking into account the data of most factors affecting the rivers runoff formation to the maximum extent, through the application of space information and fast GIS technologies. At the same time, dependence on observation data, spatial-temporal limitations, and difficulties associated with physical contact with the area are minimized. Advantages of the RCM can be used to solve most water-related problems. The water resources of the Nakhchivanchay river, given as an example in the article, were estimated at 6.805 m3/s (214.36 million m3) using RCM. There was a very small difference between the actual gauged data of the river and the volume assessed by the new method (233.8 million m3) and it amounted to only 8.31%.
https://www.researchgate.net/publication/395979118_Assessment_of_Water_Resources_in_Nakhchivanchay_River_Basin_Using_Runoff_Coefficients_Method