City water body extraction method for satellite remote sensing image

Abstract

The invention discloses a city water body extraction method for a satellite remote sensing image. The method comprises the steps of preprocessing remote sensing image data; obtaining two new normalized different water body indexes NNDWI1 and NNDWI2, and obtaining water body extraction results of NNDWI1 and NNDWI2; superposing a threshold segmentation result of NNDWI1 and a threshold segmentation result of NNDWI2 to obtain a threshold segmentation result of NNDWI, namely, a large-area water body object and a small-area object, performing constraint on the expanded small-area object, and performing shadow detection and removal on the constrained small-area object to obtain a small-area water body object; and superposing the large-area water body object and the small-area water body object to obtain a city water body extraction result of the satellite remote sensing image. The method provided by the invention has relatively high classification precision and relatively low missing detection and false alarm total error rate, improves subsequent water body extraction precision, and has relatively high water body edge detection precision.

Description

technical field [0001] The invention belongs to the technical field of remote sensing images of water bodies, and mainly relates to a method for extracting urban water bodies from satellite remote sensing images. Background technique [0002] Cities are the embodiment of the highly developed human society. As an important factor in the urban ecosystem, urban water bodies play a very important role in maintaining the stability of the urban ecosystem. Changes in urban water bodies will bring about huge changes in life, and may cause some disasters, such as urban water retention, water shortages, and even some diseases related to human healthy life. Therefore, understanding and mastering the distribution of urban water bodies and changes in water area has become the focus of increasing attention. [0003] In recent years, with the application and development of remote sensing technology, remote sensing images have played an increasingly important role in natural resource surve...

AI Technical Summary

Problems solved by technology

If the combination of high-resolution remote sensing image shadow detection method (morphological shadow index, MSI) and NDWI is used to extract water bodies from WorldView-2 high-resolution images, in order to improve the accuracy of water body detection; although the principle of this method is simple, due to This method uses the NDWI method as the basis for water body extraction, and its detection accuracy is not very high, especially in the small area of ​​water with dense vegetation around, the spectral characteristics of the water body will be seriously polluted, and the spectral characteristics of the water body are extremely unstable. The water body has the characteristics of high suspended sediment content, serious eutrophication of the water body, and high pollution by various pollutants, which makes the optical characteristics of the urban water body and the unpolluted water body in nature different.

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