Enhanced Vegetation Index (EVI) - Switzerland [2018, Sentinel-2]

This dataset is an time-serie of Sentinel-2 Analysis Ready Data (ARD)- derived Enhanced Vegetation Index (EVI) computed from Sentinel-2 data. EVI quantifies vegetation by measuring the difference between near-infrared (which vegetation strongly reflects) and red light (which vegetation absorbs) using the forumla EVI=2.5*(b8 − b4)/(b8 + 6*b4 − 7.5*b2 + 1). See Huete et al. (2002) DOI: 10.1016/S0034-4257(02)00096-2 EVI is usually used for areas with high LAI where NDVI is expected to saturate. EVI is used to quantify vegetation greenness and is useful in understanding vegetation density and assessing changes in plant health. EVI values ranges from -1 to +1. Values are provided as integer and multiplied by 1000 Metrics: annual (_annual) and seasonal (_spring; _summer; _autumn; _winter) mean (_nanmean), standard dev (_nanstd), min (_nanmin), max (_nanmax), median (_nanmedian), and amplitude (_range) Data format: GeoTiff This dataset has been genereated with the Swiss Data Cube (http://www.swissdatacube.ch) in the frame of the ValPar.CH project

本数据集为基于哨兵-2号（Sentinel-2）分析就绪数据（Analysis Ready Data, ARD）衍生的增强型植被指数（Enhanced Vegetation Index, EVI）时间序列数据。增强型植被指数通过测量近红外波段（植被强反射波段）与红光波段（植被强吸收波段）的差值实现植被量化，计算公式为：EVI=2.5*(b8 − b4)/(b8 + 6*b4 − 7.5*b2 + 1)，相关研究详见Huete等人（2002），DOI: 10.1016/S0034-4257(02)00096-2。增强型植被指数通常适用于叶面积指数（Leaf Area Index, LAI）较高、归一化植被指数（Normalized Difference Vegetation Index, NDVI）易出现饱和的区域，可用于量化植被绿度，有助于解析植被密度与评估植物健康状态变化。增强型植被指数的取值范围为-1至+1，数据以整数形式存储且已乘以1000。本数据集包含多项统计指标：年度（后缀_annual）与季节（后缀_spring代表春季、_summer代表夏季、_autumn代表秋季、_winter代表冬季）维度下的均值（_nanmean）、标准差（_nanstd）、最小值（_nanmin）、最大值（_nanmax）、中位数（_nanmedian）以及振幅（_range）。数据格式为GeoTiff。本数据集依托瑞士数据立方体（Swiss Data Cube, http://www.swissdatacube.ch），在ValPar.CH项目框架下生成。