Vegetation Condition Index (Global - Dekadal - 1 km ) - FAO ASIS

The Vegetation Condition Index (VCI) evaluates the current vegetation health in comparison to the historical trends. The VCI relates current dekadal Normalized Difference Vegetation Index (NDVI) to its long-term minimum and maximum, normalized by the historical range of NDVI values for the same dekad. The VCI was designed to separate the weather-related component of the NDVI from the ecological element. 𝑉𝐶𝐼𝑖=(𝑁𝐷𝑉𝐼𝑖−𝑁𝐷𝑉𝐼𝑚𝑖𝑛) / (𝑁𝐷𝑉𝐼𝑚𝑎𝑥−𝑁𝐷𝑉𝐼𝑚𝑖𝑛) Phenomenon Mapped: Vegetation Condition Index Units: None Time Interval: 10-day Time Extent: 1984-Present Cell Size: 1 km Pixel Type: 32-bit Signed Integer Data Projection: WGS 1984 Mosaic Projection: WGS 1984 Web Mercator Source: Food and Agriculture Organization of the United Nations Update Cycle: 10-day + 3-4 days lag Together with Temperature Condition Index (TCI), Vegetation Condition Index (VCI) is used to calculate Vegetation Health Index (VHI) using formula: VHI=0.5VCI+0.5TCI In ASIS, VCI is computed in two temporal granularities: dekadal and monthly. The dekadal/monthly VCI raster layer published is further updated in the following 5 dekads (improve data precision, remove cloud pixel etc.). Flags of raster file: 251=missing, 252=cloud, 253=snow, 254=sea, 255=background Explore this and related data in this web application More information please visit FAO GIEWS Earth Observation website植被状况指数（Vegetation Condition Index, VCI）用于对比历史趋势，评估当前植被健康状况。该指数将当前十日合成归一化差分植被指数（Normalized Difference Vegetation Index, NDVI）与同期历史NDVI的最小、最大值进行关联，并基于历史同期十日段的NDVI值域范围完成归一化处理。VCI的设计目标是将NDVI中与天气相关的组分与生态要素分离开来，计算公式为： 𝑉𝐶𝐼𝑖=(𝑁𝐷𝑉𝐼𝑖−𝑁𝐷𝑉𝐼𝑚𝑖𝑛) / (𝑁𝐷𝑉𝐼𝑚𝑎𝑥−𝑁𝐷𝑉𝐼𝑚𝑖𝑛) 制图对象：植被状况指数 单位：无 时间间隔：10日 时间范围：1984年至今 栅格单元尺寸：1 km 像素类型：32位有符号整数 数据投影：WGS 1984 镶嵌投影：WGS 1984 Web墨卡托 数据来源：联合国粮食及农业组织（Food and Agriculture Organization of the United Nations） 更新周期：每10日，存在3-4日滞后 植被状况指数（VCI）可与温度状况指数（Temperature Condition Index, TCI）结合，通过以下公式计算植被健康指数（Vegetation Health Index, VHI）：VHI=0.5VCI+0.5TCI 在ASIS系统中，VCI支持两种时间粒度的计算：十日合成尺度与月尺度。所发布的十日/月合成VCI栅格图层将在后续5个十日合成周期内进行更新，以提升数据精度、移除云像元等干扰信息。栅格文件标记值说明：251=缺失数据，252=云覆盖，253=积雪，254=海洋区域，255=背景区域 您可通过本Web应用探索本数据集及相关数据。更多信息请访问FAO GIEWS地球观测官方网站。