Enhanced Vegetation Index (EVI) - Switzerland [2020-2021, Landsat]

This dataset is an time-serie of Landsat Analysis Ready Data (ARD)- derived Enhanced Vegetation Index (EVI) computed from Landsat 5-7-8 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*(NIR − Red)/(NIR + 6*Red − 7.5*Blue + 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Landsat 5、7、8号卫星数据生成的时间序列Landsat分析就绪数据（Analysis Ready Data，ARD）衍生增强型植被指数（Enhanced Vegetation Index，EVI）数据集。增强型植被指数通过探测植被强反射的近红外波段与植被吸收的红光波段之间的差值实现植被量化，计算公式为：EVI=2.5*(NIR − Red)/(NIR + 6*Red − 7.5*Blue + 1)。相关研究细节参见Huete等人（2002）的成果，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）易出现饱和效应的区域。该指数可用于量化植被绿度，有助于解析植被密度变化并评估植物健康状况。

EVI的取值范围为-1至+1，数据以整数格式存储并已做1000倍缩放处理。

数据集包含以下统计指标：年际（后缀为_annual）与季节（后缀分别为_spring、_summer、_autumn、_winter）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。

本数据集由瑞士数据立方（Swiss Data Cube，http://www.swissdatacube.ch）在ValPar.CH项目框架下生成。