多分辨率量化全球生境的空间异质性数据集
全球栖息地异质性
这些数据集包含14个指标,根据中分辨率成像分光仪(MODIS)获取的增强植被指数(EVI)图像的纹理特征,以多种分辨率量化全球生境的空间异质性。关于这些指标的更多信息以及对其在生物多样性建模中的效用的评价。该数据集以1公里、5公里和25公里的分辨率生成,这里只列出了1公里的资产,只需根据需要用_5公里和_25公里替换_1公里。
数据集细节
在30角秒(赤道约1公里)、2.5角分(约5公里)和12.5角分(约25公里)的分辨率下,有6个一阶和8个二阶纹理测量。一阶纹理测量是描述EVI值频率分布的统计数据,测量一个地区内EVI的组成变化。二阶纹理测量是一个区域内像素对之间不同EVI组合的出现概率的统计,因此也反映了EVI值的空间排列和依赖性。
First-order texture measures
Metric | Measure | Value Range | Expected Relationship with Heterogeneity |
---|---|---|---|
Coefficient of variation | Normalized dispersion of EVI | >=0 | Positive |
Evenness | Evenness of EVI | >=0; <=1 | Positive |
Range | Range of EVI | >=0 | Positive |
Shannon | Diversity of EVI | >=0; <=ln(max # of different EVI) | Positive |
Simpson | Diversity of EVI | >=0; <=1-1/(max # of different EVI) | Positive |
Standard deviation | Dispersion of EVI | >=0 | Positive |
Second-order texture measures
Metric | Measure | Value Range | Expected Relationship with Heterogeneity |
---|---|---|---|
Contrast | Exponentially weighted difference in EVI between adjacent pixels | >=0 | Positive |
Correlation | Linear dependency of EVI on adjacent pixels | >=-1; <=1 | Nonlinear |
Dissimilarity | Difference in EVI between adjacent pixels | >=0 | Positive |
Entropy | Disorderliness of EVI | >=0 | Positive |
Homogeneity | Similarity of EVI between adjacent pixels | >=0; <=1 | Negative |
Maximum | Dominance of EVI combinations between adjacent pixels | >=0; <=1 | Negative |
Uniformity | Orderliness of EVI | >=0; <=1 | Negative |
Variance | Dispersion of EVI combinations between adjacent pixels | >=0 | Positive |
All data layers are in WGS84 projection and have a spatial extent from 85ºN - 60ºS and from 180ºW - 180ºE. The pixel values of the data layers should be mulitplied by 0.0001 to obtain the actual values of the metrics.
Dataset Citation
Project Website:
App Website:
Curated by: Samapriya Roy
Keywords: Earthenv, habitat heterogeneity, shannon, simpson, pielou, dissimilarity, homogeneity, variance, contrast
Last updated: 2021-05-09
Paper Citation
Earth Engine Snippet
Sample Script:
License
Global Habitat Heterogeneity Metrics Version 1 by Tuanmu & Jetz is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. Permissions beyond the scope of this license may be available at
.Dataset Citation
Project Website:
App Website:
Curated by: Samapriya Roy
Keywords: Earthenv, habitat heterogeneity, shannon, simpson, pielou, dissimilarity, homogeneity, variance, contrast
Last updated: 2021-05-09
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