MODIS NDWI, monthly aggregated time series for Mauritania at 30 arc seconds (ca. 1000 meter) resolution (2019 - 2023)

Normalized Difference Water Index (NDWI) from MODIS data for Mauritania at 30 arc seconds (ca. 1000 meter) resolution (2019 - 2023).

Source data:

- MODIS/Terra Surface Reflectance 8-Day L3 Global 500 m SIN Grid (MOD09A1 v061): https://lpdaac.usgs.gov/products/mod09a1v061/

The Moderate Resolution Imaging Spectroradiometer (MODIS) Terra MOD09A1 Version 6.1 product provides an estimate of the surface spectral reflectance of Terra MODIS Bands 1 through 7 corrected for atmospheric conditions such as gasses, aerosols, and Rayleigh scattering. Along with the seven 500 meter (m) reflectance bands are two quality layers and four observation bands. For each pixel, a value is selected from all the acquisitions within the 8-day composite period. The criteria for the pixel choice include cloud and solar zenith. When several acquisitions meet the criteria the pixel with the minimum channel 3 (blue) value is used.

For the time period January 2019 - December 2023, the NDWI has been calculated from the Terra MOD09A1 Version 6.1 product. The layers B02 (near infrared) and B06 (shortwave infrared) of the original data have been processed. Bad quality pixels or pixels with snow/ice and/or cloud cover have been masked using the provided quality assurance (QA) layer. The time series has been gapfilled with a temporal and a spatial approach. Gaps in the time series were filled with a harmonic analysis of time series using six frequencies to also model relatively short-term changes in NDWI. Only missing values were replaced by modelled values. NDWI was calculated as the normalized difference of the bands B02 (near infrared) and B06 (shortwave infrared) with: NDWI = (B02 – B06) / (B02 + B06). This NDWI represents vegetation water content. The 8-day data are then aggregated to monthly temporal resolution using the average and reprojected to Latitude-Longitude/WGS84.

File naming:

ndwi_monthly_YYYY_MM_30arcsec.tif

e.g.: ndwi_monthly_2023_12_30arcsec.tif

The date within the filename are year and month of aggregated timestamp.

Pixel values:

Raster values are in the range [0, 2000]. Real NDWI in the range [-1, 1] can be retrieved with: NDWI = raster_value * 0.001 - 1.

Projection + EPSG code:

Latitude-Longitude/WGS84 (EPSG: 4326)

Spatial extent:

north: 28N

south: 14N

west: 18W

east: 4W

Temporal extent:

January 2019 - December 2023

Spatial resolution:

30 arc seconds (approx. 1000 m)

Temporal resolution:

monthly

Software used:

GRASS GIS 8.3.2

Format: GeoTIFF

Original dataset license:

All data products distributed by NASA's Land Processes Distributed Active Archive Center (LP DAAC) are available at no charge. The LP DAAC requests that any author using NASA data products in their work provide credit for the data, and any assistance provided by the LP DAAC, in the data section of the paper, the acknowledgement section, and/or as a reference. The recommended citation for each data product is available on its Digital Object Identifier (DOI) Landing page, which can be accessed through the Search Data Catalog interface. For more information see: https://lpdaac.usgs.gov/products/mod13a2v061/

Processed by:

mundialis GmbH & Co. KG, Germany (https://www.mundialis.de/)

Contact:

mundialis GmbH & Co. KG, info@mundialis.de

Acknowledgements:

This study was partially funded by EU grant 874850 MOOD. The contents of this publication are the sole responsibility of the authors and don't necessarily reflect the views of the European Commission.

Citation proposal
(2025) . MODIS NDWI, monthly aggregated time series for Mauritania at 30 arc seconds (ca. 1000 meter) resolution (2019 - 2023). https://gdk.gdi-de.org/geonetwork/srv/api/records/e4941c0b-27c0-4522-857f-5e02d719721e

INSPIRE
SDS

INSPIRE

Identification

File identifier: e4941c0b-27c0-4522-857f-5e02d719721e XML

Hierarchy level: Dataset

Online resource

Protocol: WWW:DOWNLOAD-1.0-http--download

Protocol: WWW:DOWNLOAD-1.0-http--download

Protocol: WWW:DOWNLOAD-1.0-http--download

Protocol: WWW:DOWNLOAD-1.0-http--download

Protocol: WWW:DOWNLOAD-1.0-http--download

Resource identifier

code: 10.5281/zenodo.14764686

Metadata language: English

Spatial representation type: Grid

Encoding

Format: GeoTiff

Version

Projection

code: WGS 84 (EPSG:4326)

Classification of data and services

Topic category

Geoscientific information
Health

Classification of data and services

Coupled resource

Classification of data and services

Coupled resource

Keywords

GEMET - INSPIRE themes, version 1.0 ( Theme )

Human health and safety

Other keywords

Keywords ( Theme )

MOOD-H2020
Normalized Difference Water Index
NDWI
Rift Valley Fever
RVF

Keywords ( Place )

Mauritania

Geographic coverage

Temporal reference

Temporal extent

Date ( Publication ): 2025-01-30

Quality and validity

Lineage

Derived from: MODIS/Terra Surface Reflectance 8-Day L3 Global 500 m SIN Grid (MOD09A1 v061): https://lpdaac.usgs.gov/products/mod09a1v061/

NDWI has been calculated from the Terra MOD09A1 Version 6.1 product. The layers B02 (near infrared) and B06 (shortwave infrared) of the original data have been processed. Bad quality pixels or pixels with snow/ice and/or cloud cover have been masked using the provided quality assurance (QA) layer. The time series has been gapfilled with a temporal and a spatial approach.

Distance: 30 arc-seconds

Conformity

Explanation: See specified reference

Restrictions on access and use

Access constraints: All data products distributed by NASA's Land Processes Distributed Active Archive Center (LP DAAC) are available at no charge.

Access constraints

All LP DAAC current data and products acquired through the LP DAAC have no restrictions on reuse, sale, or redistribution.

The LP DAAC requests that any author using NASA data products in their work provide credit for the data, and any assistance provided by the LP DAAC, in the data section of the paper, the acknowledgement section, and/or as a reference. The recommended citation for each data product is available on its Digital Object Identifier (DOI) Landing page, which can be accessed through the Search Data Catalog interface.

For full information on LP DAAC Data Citation and Policies, see: https://lpdaac.usgs.gov/data/data-citation-and-policies/