TROPICAL GEOGRAPHY ›› 2015, Vol. 35 ›› Issue (3): 386-392.

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Extraction of Remote Sensing Information of Karst Rocky Desertification on the Scale of Small Watershed

LI Song1,2,LUO Xuqiang1,3   

  1. (1.Institute of Resources,Environment and Disasters,Guiyang 550018,China;2.Institute of Remote Sensing and Digital Earth,Chinese Academy of Sciences,Beijing 100101,China;3.Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550002,China)
  • Online:2015-06-05 Published:2015-06-05

Abstract:

A segmentation approach based on small watershed patches to karst rocky desertification information extraction was presented to improve the objectivity of karst rocky desertification mapping. Taking the western region of Guizhou Province as a study case, this paper tested the segmentation approach based on small watershed patches to rocky desertification information extraction by using DEM (30 m) and an image of Landsat 8 captured on June 16, 2013. Consequentially, desertification stability index (DSI) was developed to analyze the effects of different patches on karst rocky desertification information, which were extracted from land use patches based on the image captured in 2013. The results showed that the percentage of moderate desertification or better extracted from two kinds of patches was over 80% of the karst area in study case. There was a variable difference in rocky desertification based on the two categories of patches, and the values of non-obvious, slight, moderate, severe and intense desertification were 66.5%, 26.8%, 72.4%, 75.4% and 55.9% respectively. The value of DSI was just 0.15. The segmentation method based on small watershed patches had a significant effect on karst rocky desertification information extraction. Finally, the image segmentation method based on small watershed patches indicated a geographical significance and stability, which was an effective method of karst rocky desertification information extraction.

Key words: small watershed scale, digital elevation model, karst rocky desertification, remote sensing, information extraction