Author(s): Han Congji; Kawaike Kenji; Wada Keiko; Koshiba Takahiro
Linked Author(s): Kenji Kawaike
Keywords: Parameter identification inverse method subset simulation pollutant transport optimization problem
Abstract: Conciliation of water resource management has become a significant challenge with the increasing extreme weather events and human activities. Environmental hydraulics models, as mathematical and computational models capable of describing the water quality of a given water body, serve as valuable tools due to their ability to simulate various scenarios and the possibility to support decision-making in water resource management. However, the difficulty in calculating or measuring key parameters of environmental hydraulics models, such as hydrodynamic parameters, dispersion coefficients, and source and sink terms, remains a major obstacle. In this paper, Inverse Problem Methods are applied to estimate the environmental hydraulics parameters of hypothetical conservative pollutant release events. The advection-diffusion equation is employed to model pollutant transport. By introducing an objective function, the inverse problem is transformed into an optimization problem, which is solved using a heuristic algorithm -- the Subset Simulation method. The proposed method is tested using sampling data of pollutant concentration with noise. In scenarios without obstacles, the proposed method achieves reliable results even with data containing noise levels of ±20%. On the other hand, in scenarios with obstacles, the proposed method also shows robust performance. The results of this paper demonstrated the feasibility of inverse problem methods in estimating environmental hydraulics parameters with satisfactory accuracy based on concentration data from measurement points.
Year: 2025