Abstract: Despite wide application abroad, the “abcd” water balance model is barely used in China. In order to explore the applicability and effectiveness of the “abcd” model in small and medium-sized watersheds in China, we first of all expound the principle and structure of the “abcd” model, and applied the model to the runoff forecasting simulation for Xin’an River Basin. Moreover, we examined the sensitivity of four parameters of the “abcd” model for the first time in China by comparing the simulated values with measured values, and further discussed the responses of performance indicators to parameter changes using univariate and multivariate methods. Results manifested that Nash-Sutcliffe efficiency (NSE)in verification is 0.929 in flood season and 0.863 in non-flood season, indicating a high fitting degree. Meanwhile, sensitivity analysis could evidently improve the efficiency and accuracy of calibration. Result of the univariate method is similar to that of the multivariate method, and NSE is the most sensitive to parameter c. In conclusion, the “abcd” model can be widely applied to small and medium-sized watersheds in China with high accuracy and adaptability.

Key words: “abcd” water balance model, runoff simulation, sensitivity analysis, performance index, multivariate method, Xin’an River Basin