JOURNAL OF NATURAL RESOURCES ›› 2015, Vol. 30 ›› Issue (6): 1024-1034.doi: 10.11849/zrzyxb.2015.06.013

• Resource Research Method • Previous Articles     Next Articles

Research on Biological Soil Crust Extraction by Spectral Analysis in Mu Us Desert, China

FENG Xiu-rong1, BU Chong-feng2,5, HAO Hong-ke3, YANG Yan-zheng3, ZHANG Guang-jun4   

  1. 1. College of Science, Northwest A & F University, Yangling 712100, China;
    2. Institute of Soil and Water Conservation, Northwest A & F University, Yangling 712100, China;
    3. College of Forestry, Northwest A & F University, Yangling 712100, China;
    4. College of Environment and Resource, Northwest A & F University, Yangling 712100, China;
    5. Institute of Soil and Water Conservation, CAS & Ministry of Water Resources, Yangling 712100, China
  • Received:2014-04-14 Revised:2014-08-24 Online:2015-06-20 Published:2015-06-20

Abstract:

Using the hyperspectral reflectance data of typical objects and TM remote sensing images, the paper extracts the moss-dominated biological soil crusts at vigorous growth stage (from July to August) in Mu Us Desert. We collected the reflectance spectra of six typical ground features including bare sand, algae crust, dry vegetation, green vegetation, the moss crusts of 33% coverage and 100% coverage. Remote sensing data include twelve Landsat TM images acquired from July to August in 2010 and 2011. The results are as follows: 1) Moss crust in vigorous growth stage has similar spectral reflectance curves with green plants. There are obvious reflection peak and“red edge”phenomenon in visible light band. However, in the red band (680-760 nm), they have differences in all“red edge”parameters including red edge amplitude, red edge width and red edge area, except red edge position. In the near- infrared shortwave bands(760-900 nm), the reflectance of moss crust is much lower than that of green plants. Their average reflectance is 0.198 and 0.424 respectively. Moss crust has no reflection peak at the wavelength of 550 nm, but at the wavelength of 625 nm. The moss crust of 33% coverage, algae crust and dry vegetation have similar spectral curves between the wavelength of 400 nm and 900 nm. Their spectral reflectance is lower than that of bare sand which is 48%. 2) Based on the Landsat TM images, the method extracts biological crust by combing biological soil crust index (BSCI), normalized difference vegetation index (NDVI), supervised classification and slope classification. 3) The pixel area of moss crusts is 7200 km2, which takes 6.43% of the total study area.

Key words: Mu Us Desert, extraction, biological soil crust, spectral characteristic, TM remote sensing image

CLC Number: 

  • S127