NDVI, NDBI, NDWI, and NDMI are all indices that are commonly used in remote sensing and GIS applications to analyze various land cover and land use characteristics. Here is a brief explanation of each index.

NDVI (Normalized Difference Vegetation Index): NDVI is used to evaluate vegetation density and health. It is calculated using the red and near-infrared (NIR) bands of remote sensing data, and ranges from -1 to 1. Higher values indicate a higher density of healthy vegetation.

NDBI (Normalized Difference Built-Up Index): NDBI is used to identify and map built-up areas such as buildings and roads. It is calculated using the near-infrared (NIR) and shortwave-infrared (SWIR) bands of remote sensing data, and ranges from -1 to 1. Higher values indicate a higher density of built-up areas.

NDWI (Normalized Difference Water Index): NDWI is used to identify and map water bodies such as rivers, lakes, and wetlands. It is calculated using the green and NIR bands of remote sensing data, and ranges from -1 to 1. Higher values indicate a higher density of water.

NDMI (Normalized Difference Moisture Index): NDMI is used to evaluate the moisture content in vegetation. It is calculated using the NIR and mid-infrared (MIR) bands of remote sensing data, and ranges from -1 to 1. Higher values indicate a higher moisture content in vegetation.

Author of the text : Douha AKKARI, GIS Specialist, Geographer. Reach out her Linkedin Page.