Regional water body drawing method based on Landsat OLI remote sensing image

Abstract

The invention discloses a regional water body drawing method based on a Landsat OLI remote sensing image. The regional water body drawing method comprises the following steps: 1) constructing a universal water body index model; 2) automatically selecting an optimal water body index threshold value; 3) extracting regional water body; 4) verifying a water body extraction result; and 5) performing regional water body drawing. The method is based on an existing water body index model, and a regional water body extraction index model suitable for a Landsat OLI remote sensing image is developed. After a model wave band is adopted for operation, water body and non-water body type value domains can be effectively separated, wherein the water body shows a relatively concentrated value domain range,an image entropy algorithm is adopted to overcome the reflectivity heterogeneity of the land-saving object caused by space-time difference, and the algorithm automatically selects the optimal water body to extract the threshold value, so that the uncertainty and subjectivity of manually determining the threshold value are reduced, and the drawing precision and efficiency of the water body are improved.

Description

technical field [0001] The invention relates to a regional water body remote sensing mapping method, in particular to a regional water body mapping method based on Landsat OLI remote sensing images, and belongs to the technical field of remote sensing mapping. Background technique [0002] With the deepening and progress of research on modern water mapping methods, the construction method of water body extraction index model is also continuously improved and improved: in 1996, Mcfeeters first used green light (Green, 0.52-0.60um) band and near infrared (NIR , 0.76-0.96um) band to construct the normalized difference water index (NDWI). In 2004, Roger and Kearney used the red (Red, 0.62-0.69um) band and short-wave infrared (SWIR1, 1.55-1.75um) band to propose another An index model for water extraction, which can effectively identify water and bare soil; in 2005, Professor Xu Hanqiu used green light (Green, 0.52-0.60 μm) and short-wave infrared (SWIR1, 1.55-1.75 μm) to constru...

AI Technical Summary

Problems solved by technology

[0006] (1) Existing water body index models seldom take into account the influence of remote sensing images in different geographical spaces on water reflection values. Time-consuming and labor-intensive;

[0007] (2) Most of the existing water body index models do not take into account the influence of seasonal changes on the reflectance of water bodies. Since there are certain differences in the reflectance of the same ground features in different seasons, when using a constant water body index threshold to extract water bodies, it will lead to the extracted The accuracy of the water body is inconsistent and the volatility is large;

[0008] (3) The selection of the threshold of the existing index model is highly subjective, and the accuracy of water extraction varies with the selection of the threshold

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