|Title:||Integration of Landscape Metrics and Variograms to Characterize and Quantify the Spatial Heterogeneity Change of Vegetation Induced by the 2008 Wenchuan Earthquake|
|Author's alias:||小池, 克明|
|Journal title:||ISPRS International Journal of Geo-Information|
|Abstract:||The quantification of spatial heterogeneity can be used to examine the structure of ecological systems. The 2008 Wenchuan earthquake caused severe vegetation damage. In addition to simply detecting change, the magnitude of changes must also be examined. Remote sensing and geographic information system techniques were used to produce landscape maps before and after the earthquake and analyze the spatial-temporal change of the vegetation pattern. Landscape metrics were selected to quantify the spatial heterogeneity in a categorical map at both the class and landscape levels. The results reveal that the Wenchuan earthquake greatly increased the heterogeneity in the study area. In particular, forests experienced the most fragmentation among all of the landscape types. In addition, spatial heterogeneity in a numerical map was studied by using variogram analysis of normalized difference vegetation indices derived from Landsat images. In comparison to before the earthquake, the spatial variability after the earthquake had doubled. The structure of the spatial heterogeneity represented by the range of normalized difference vegetation index (NDVI) variograms also changed due to the earthquake. Moreover, the results of the NDVI variogram analysis of three contrasting landscapes, which were farmland, broadleaved forest, and coniferous forest, confirm that the earthquake produced spatial variability and changed the structure of the landscapes. Regardless of before or after the earthquake, farmland sites are the most heterogeneous among the three landscapes studied.|
|Rights:||© 2017 by the authors. Licensee MDPI, Basel, Switzerland. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).|
|Appears in Collections:||Journal Articles|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.