Urban catchment area refined extraction method considering DSM and DLG

Abstract

The invention discloses an urban catchment area refined extraction method considering DSM and DLG, and the method comprises the following steps: the step 1, obtaining urban DSM data and correspondingDLG data, and carrying out the rasterization of the DSM data and the DLG data, and obtaining a DSM grid and a DLG grid; the step 2, removing a non-waterlogged area in the DSM grids; the step 3, calculating the flow direction of the DSM grids after the non-waterlogged area is removed to obtain flow direction grid data; the step 4, combining the DLG raster data and the flow direction raster data tocalculate flow; the step 5, setting a threshold value, extracting a catchment route according to the threshold value, and further extracting a water outlet; and the step 6, extracting to obtain a catchment area according to the data of the water outlet and the flow direction grid. According to the method, the DSM is adopted to divide the urban catchment area, so that the influence of urban planning and construction on urban terrain transformation can be well reflected, and the method is more practical; and the problem that a non-waterlogged area cannot be treated in a traditional catchment area dividing method is solved.

Description

technical field [0001] The present invention relates to the technical field of hydrological analysis, in particular to a method for finely extracting urban catchment areas in consideration of DSM (Digital Surface Model) and DLG (Digital Line Graphic). Background technique [0002] With the continuous acceleration of the urbanization process in our country, the natural cycle of water has been artificially cut off, and frequent rainstorms and waterlogging occur. The problem of torrential rain and waterlogging in Chinese cities is quite serious. Between 2008 and 2010, 62% of the cities suffered from waterlogging to varying degrees, and there were hundreds of cities with more than 3 waterlogging disasters. Among the cities that experienced waterlogging, about The longest flooding time in more than half of the cities exceeds 12 hours. At present, there are still a considerable number of cities in the country that have not met the flood control standards stipulated by the state. ...

AI Technical Summary

Problems solved by technology

[0004] There are also some urban rainstorm and waterlogging assessment models that use the D8 algorithm to divide the catchment area on the DSM data, which can reflect the impact of urban planning and construction on urban topography to a certain extent, but if the roof of the house is sunken , which will lead to the existence of catchment area in the house plane

The emergence of these problems will lead to the division of the catchment area is not fine enough, or even inaccurate, resulting in large errors in the subsequent evaluation of waterlogging

Images