Development of a simplified grid cells ordering method facilitating GIS-based spatially distributed hydrological modeling

In many spatially distributed hydrological models the watershed is discretized into grid cells each of which represents an area with average properties. The hydrological response of these cells is flowing downhill from one cell to other neighboring cells until it reaches the specified outlet. However, in these models the computations should proceed in correct hydrological sequence. In this study, an alternative simplified grid cells ordering method, facilitating GIS-based spatially distributed hydrological modeling, is presented. The proposed method utilizes recent developments on the analysis of grid-based terrains to serialize the grid cells of the studied area to a single thread representing a proper hydrologic cascading system. The main advantage of this new method is that it is very simple, but at the same time efficient. Furthermore, the resulted ordered sequence of cells can be accessed serially in a single pass for each time step, enhancing the performance and simplifying the implementation of hydrological models.