Integrating Remotely Sensed Data Using a Simple Vegetation Parameter Aggregation Method Applicable to a Distributed Rainfall-Runoff Model

摘要

The specification of the land cover characteristics is essential to have runoff simulated by a rainfall-runoff (RR) model in watershed hydrology. The recent availability of land cover map from remotely sensed data makes the specification of the land cover characteristics easier but it is unlikely that the RR models incorporate all spatial scales of the land cover map in need of application. This paper proposes a simple but physically based aggregation method to upscale natural vegetative heterogeneity, which is represented by Manning's roughness coefficient, to the grid scale used in typical RR model, and it compares the strength of the new method with the conventional methods and uses a hydrologic model to test the sensitivity of using different methods. The results show the new method provides better performance in terms of both the amount and time to peak flow in relative terms. The proposed method provides a reasonably realistic description of area-averaged vegetation nature and characteristics.