Mapping Plant Functional Types over Broad Mountainous Regions: A Hierarchical Soft Time-Space Classification Applied to the Tibetan PlateauReportar como inadecuado




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1

Institute of Remote Sensing and Digital Earth, University of Chinese Academy of Sciences, Beijing, 100101, China

2

Max-Planck-Institute for Meteorology, Hamburg, 20146, Germany





*

Author to whom correspondence should be addressed.



Abstract Research on global climate change requires plant functional type PFT products. Although several PFT mapping procedures for remote sensing imagery are being used, none of them appears to be specifically designed to map and evaluate PFTs over broad mountainous areas which are highly relevant regions to identify and analyze the response of natural ecosystems. We present a methodology for generating soft classifications of PFTs from remotely sensed time series that are based on a hierarchical strategy by integrating time varying integrated NDVI and phenological information with topography: i Temporal variability: a Fourier transform of a vegetation index MODIS NDVI, 2006 to 2010. ii Spatial partitioning: a primary image segmentation based on a small number of thresholds applied to the Fourier amplitude. iii Classification by a supervised soft classification step is based on a normalized distance metric constructed from a subset of Fourier coefficients and complimentary altitude data from a digital elevation model. Applicability and effectiveness is tested for the eastern Tibetan Plateau. A classification nomenclature is determined from temporally stable pixels in the MCD12Q1 time series. Overall accuracy statistics of the resulting classification reveal a gain of about 7% from 64.4% compared to 57.7% by the MODIS PFT products. View Full-Text

Keywords: plant functional types; fast Fourier transform; NDVI time series; Tibetan Plateau plant functional types; fast Fourier transform; NDVI time series; Tibetan Plateau





Autor: Danlu Cai 1,2,* , Yanning Guan 1, Shan Guo 1, Chunyan Zhang 1 and Klaus Fraedrich 2

Fuente: http://mdpi.com/



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