2015-2018年一带一路区域地球大数据生态环境专题数据集

植被水分指数NDWI是基于中红外与近红外波段的归一化比值指数。与NDVI相比, 它能有效地提取植被冠层的水分含量;在植被冠层受水分胁迫时, NDWI指数能及时地响应, 这对于旱情监测具有重要意义。此数据通过Landsat8原值数据进行DN值转换，然后再进行NDWI数值计算。数据集压缩文件内为计算NDWI后的影像的切片数据，像素大小为256*256.由于文件量过大，因此采用压缩的形式给用户提供便捷的查看和下载。geojson内包含每个文件所属的边界及切片信息。

The Normalized Difference Water Index (NDWI) is a normalized ratio index based on the mid-infrared and near-infrared bands. Compared with the Normalized Difference Vegetation Index (NDVI), it can effectively extract the water content of vegetation canopies. When vegetation canopies are under water stress, the NDWI index can respond in a timely manner, which is of great significance for drought monitoring. This dataset is generated by converting DN values from raw Landsat 8 data, followed by NDWI value calculation. The compressed dataset package contains sliced image data obtained after NDWI calculation, with each slice having a pixel size of 256×256. Due to the large total file size, the compressed format is adopted to facilitate convenient viewing and downloading for users. The GeoJSON file contains the boundary and slice information corresponding to each image file.