2018 Volume 74 Issue 5 Pages I_145-I_150
To seek accurate quantification of material transport in a watershed is an urgent issue in the examination of adaptation measures against climate change. A distributed hydrological model is a powerful tool for the issue, though there are many parameters and their values have wide ranges. The setting of parameters and validation take much effort. In this study, we developed an adjoint code of a distributed hydrological model and a method to estimate the spatial variability of parameters using the adjoint method. We applied this method to the Ibo River and assimilated river discharge, and estimated the parameters such as roughness coefficient, hydraulic conductivity, and storage coefficients. The results showed the adjoint model can estimate their spatial distributions suited to their characteristics. Especially, they were largely corrected from the middle area where the total precipitation was large to the assimilation point in the lower watershed. The simulations using the corrected parameters show the data assimilation can improve the peak discharge.
PROCEEDINGS OF HYDRAULIC ENGINEERING
