Abstract: The surface formed by the influence of the meteorological disasters is no more than a polygon in its geometry shape. And the assimilatory meteorological elements, the character of the underlying surface, the habitat and accumulative assets of human beings are all combined on the characteristic influencing dimension of disaster, so that the condition indicates significant difference on the distribution and space background. However, the spatial analysis and the method of morphology to initialize the digitized dynamical convolution operator are generally implemented, according to the multi-types of land use and the land cover represented by the complexity of underlying surface on the urban area. Supported by the combined GIS and the morphology technique, the gridded atlas of the meteorological map is handled by the operation of erosion or dilation. Moreover, with the dynamical erosion and dilation operation to the grid map derived from the map containing the contour lines of these meteorological elements, such as the temperature, the precipitation, the humidity, and any of those observations when the disasters occur, the gridded atlas for the urban area influenced by the disaster could be set up, it would be a good way to evaluate the meteorological disasters. The research on the high temperature event occurred on July 22, 1999 is carried out as a case study, and it shows that the grids which near or contain the water or green land have been applied with the erosion operation. On the contrary, the grids which are mainly made up of buildings, roads, or cement surfaces are applied with the dilation. The conclusion drawn by the research is conformity with the characteristic of the land surface processed in the urbanized underlying surface, and even the responding behavior is extremely similar. The effectiveness of the case study is very good by applying the spatial evaluating model, and the outcome by the form of atlas is consistent with the actual situation influenced by the disaster. It is also demonstrated that the disaster evaluation with the morphological method is easy to operate, and has the ability to deal with the multi-factors that bring about the loss of disaster, by which the characteristic of the distribution is embodied.