Sensitivity Analysis of Parameters in HEC-RAS Software

As for the level of tail-water often rose when the situation of tailrace river changing during the process of construction of hydroelectric power station, one-dimensional mathematical model is used through two procedures to solve this problem. In the first, the sensitivity of three key parameters including roughness, cross-section spacing Δs, starting regulation level and section in the mathematical model were discussed. The results indicate that: (1) Positive relationship between ΔY/Y and n, shows the greater flow rate, the more sensitive of water depth changes to roughness coefficient; (2) The cross-section spacing Δs affect the large flow more obvious than the smaller; (3) The effect of the middle and lower reaches of river are bigger than the upstream. Research results provided guidance of model parameters selection.