Ces données ont été générées à l'aide de 4 185 439 scènes Landsat 5, 7 et 8 acquises entre le 16 mars 1984 et le 31 décembre 2019.
Chaque pixel a été classé individuellement dans la catégorie "eau" ou "non-eau" à l'aide d'un système expert. Les résultats ont été compilés dans un historique mensuel pour l'ensemble de la période et deux époques (1984-1999, 2000-2019) pour la détection des changements.
Ce produit de cartographie se compose d'une image contenant sept bandes.
Elle cartographie différentes facettes de la distribution spatiale et temporelle des eaux de surface au cours des 35 dernières années. Les zones où de l'eau n'a jamais été détectée sont masquées.
Bracelets
Taille des pixels 30 mètres
Bandes de fréquences
Nom
Unités
Min
Max
Taille des pixels
Description
occurrence
%
0
100
mètres
La fréquence à laquelle de l'eau était présente.
change_abs
%
-100
100
mètres
Variation absolue de l'occurrence entre deux époques : 1984-1999 et 2000-2019.
change_norm
%
-100
100
mètres
Variation normalisée de l'occurrence. (epoch1-epoch2)/(epoch1+epoch2) * 100
seasonality
0
12
mètres
Nombre de mois où l'eau est présente.
recurrence
%
0
100
mètres
Fréquence à laquelle l'eau revient d'une année sur l'autre.
transition
mètres
Classification catégorielle de l'évolution entre la première et la dernière année.
max_extent
mètres
Image binaire contenant la valeur 1 partout où de l'eau a été détectée.
Masque de bits pour max_extent
Bit 0 : indicateur indiquant si de l'eau a été détectée ou non
0 : Pas de l'eau
1 : Eau
Tableau de classe de transition
Valeur
Couleur
Description
0
#ffffff
Aucun changement
1
#0000ff
Permanente
2
#22b14c
Nouveau permanent
3
#d1102d
Perte définitive
4
#99d9ea
Saisonnier
5
#b5e61d
Nouveaux contenus saisonniers
6
#e6a1aa
Saisonnalité perdue
7
#ff7f27
Passer d'un contenu saisonnier à un contenu permanent
8
#ffc90e
Passer d'un forfait permanent à un forfait saisonnier
9
#7f7f7f
Éphémère permanent
10
#c3c3c3
Éphémère saisonnier
Conditions d'utilisation
Conditions d'utilisation
Toutes les données présentées ici sont produites dans le cadre du programme Copernicus et sont fournies sans frais, sans restriction d'utilisation. Pour obtenir des informations complètes sur la licence, consultez le règlement Copernicus.
Les publications, les modèles et les produits de données qui utilisent ces ensembles de données doivent inclure les remerciements appropriés, y compris en citant les ensembles de données et l'article de revue comme dans la citation suivante.
Si vous utilisez les données comme calque dans une carte publiée, veuillez inclure le texte d'attribution suivant : "Source : CE JRC/Google".
Citations
Citations :
Jean-Francois Pekel, Andrew Cottam, Noel Gorelick, Alan S. Belward,
High-resolution mapping of global surface water and its long-term changes.
Nature 540, 418-422 (2016). (doi:10.1038/nature20584)
Cet ensemble de données contient des cartes de l'emplacement et de la distribution temporelle des eaux de surface de 1984 à 2019, et fournit des statistiques sur l'étendue et l'évolution de ces eaux de surface. Pour en savoir plus, consultez l'article de revue associé : High-resolution mapping of global surface water and its long-term changes (Nature, 2016) et …
[null,null,[],[[["\u003cp\u003eThis dataset provides maps of global surface water and its changes from 1984 to 2019, derived from Landsat 5, 7, and 8 imagery.\u003c/p\u003e\n"],["\u003cp\u003eIt includes occurrence, change, seasonality, recurrence, and transition classifications of surface water.\u003c/p\u003e\n"],["\u003cp\u003eThe dataset offers various bands, including water frequency, change detection, and seasonality, at a 30-meter resolution.\u003c/p\u003e\n"],["\u003cp\u003eData is freely available for use with proper attribution to EC JRC/Google and citation of the associated journal article.\u003c/p\u003e\n"],["\u003cp\u003eUsers can explore and analyze the data using Google Earth Engine.\u003c/p\u003e\n"]]],["The dataset maps surface water's location and temporal distribution from March 16, 1984, to December 31, 2019, using Landsat data. It classifies each pixel as water or non-water, providing monthly histories and change detection for two epochs (1984-1999 and 2000-2019). Seven bands map the spatial and temporal distribution, including water occurrence, change, seasonality, recurrence, and transitions. The data, provided by EC JRC/Google, is available through Google Earth Engine and is free to use with proper citation.\n"],null,["# JRC Global Surface Water Mapping Layers, v1.2 [deprecated]\n\nDataset Availability\n: 1984-03-16T00:00:00Z--2020-01-01T00:00:00Z\n\nDataset Provider\n:\n\n\n [EC JRC / Google](https://global-surface-water.appspot.com)\n\nTags\n:\n[geophysical](/earth-engine/datasets/tags/geophysical) [google](/earth-engine/datasets/tags/google) [jrc](/earth-engine/datasets/tags/jrc) [landsat-derived](/earth-engine/datasets/tags/landsat-derived) [surface](/earth-engine/datasets/tags/surface) [surface-ground-water](/earth-engine/datasets/tags/surface-ground-water) [water](/earth-engine/datasets/tags/water) \n\n#### Description\n\nThis dataset contains maps of the location and temporal\ndistribution of surface water from 1984 to 2019 and provides\nstatistics on the extent and change of those water surfaces.\nFor more information see the associated journal article: [High-resolution\nmapping of global surface water and its long-term changes](https://www.nature.com/nature/journal/v540/n7633/full/nature20584.html)\n(Nature, 2016) and the online [Data Users Guide](https://storage.googleapis.com/global-surface-water/downloads_ancillary/DataUsersGuidev2.pdf).\n\nThese data were generated using 4,185,439 scenes from Landsat\n5, 7, and 8 acquired between 16 March 1984 and 31 December 2019.\nEach pixel was individually classified into water / non-water\nusing an expert system and the results were collated into a monthly\nhistory for the entire time period and two epochs (1984-1999,\n2000-2019) for change detection.\n\nThis mapping layers product consists of 1 image containing 7 bands.\nIt maps different facets of the spatial and temporal distribution of\nsurface water over the last 35 years. Areas where water has\nnever been detected are masked.\n\n### Bands\n\n\n**Pixel Size**\n\n30 meters\n\n**Bands**\n\n| Name | Units | Min | Max | Pixel Size | Description |\n|---------------|-------|------|-----|------------|---------------------------------------------------------------------------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|\n| `occurrence` | % | 0 | 100 | meters | The frequency with which water was present. |\n| `change_abs` | % | -100 | 100 | meters | Absolute change in occurrence between two epochs: 1984-1999 vs 2000-2019. |\n| `change_norm` | % | -100 | 100 | meters | Normalized change in occurrence. (epoch1-epoch2)/(epoch1+epoch2) \\* 100 |\n| `seasonality` | | 0 | 12 | meters | Number of months water is present. |\n| `recurrence` | % | 0 | 100 | meters | The frequency with which water returns from year to year. |\n| `transition` | | | | meters | Categorical classification of change between first and last year. |\n| `max_extent` | | | | meters | Binary image containing 1 anywhere water has ever been detected. |\n| Bitmask for max_extent - Bit 0: Flag indicating if water was detected or not - 0: Not water - 1: Water ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||\n\n**transition Class Table**\n\n| Value | Color | Description |\n|-------|---------|-----------------------|\n| 0 | #ffffff | No change |\n| 1 | #0000ff | Permanent |\n| 2 | #22b14c | New permanent |\n| 3 | #d1102d | Lost permanent |\n| 4 | #99d9ea | Seasonal |\n| 5 | #b5e61d | New seasonal |\n| 6 | #e6a1aa | Lost seasonal |\n| 7 | #ff7f27 | Seasonal to permanent |\n| 8 | #ffc90e | Permanent to seasonal |\n| 9 | #7f7f7f | Ephemeral permanent |\n| 10 | #c3c3c3 | Ephemeral seasonal |\n\n### Terms of Use\n\n**Terms of Use**\n\nAll data here is produced under the Copernicus Programme and is provided\nfree of charge, without restriction of use. For the full license\ninformation see the Copernicus Regulation.\n\nPublications, models, and data products that make use of these datasets\nmust include proper acknowledgement, including citing datasets and the\njournal article as in the following citation.\n\nIf you are using the data as a layer in a published map, please include the\nfollowing attribution text: 'Source: EC JRC/Google'\n\n### Citations\n\nCitations:\n\n- Jean-Francois Pekel, Andrew Cottam, Noel Gorelick, Alan S. Belward,\n High-resolution mapping of global surface water and its long-term changes.\n Nature 540, 418-422 (2016). ([doi:10.1038/nature20584](https://doi.org/10.1038/nature20584))\n\n### Explore with Earth Engine\n\n| **Important:** Earth Engine is a platform for petabyte-scale scientific analysis and visualization of geospatial datasets, both for public benefit and for business and government users. Earth Engine is free to use for research, education, and nonprofit use. To get started, please [register for Earth Engine access.](https://console.cloud.google.com/earth-engine)\n\n### Code Editor (JavaScript)\n\n```javascript\nvar dataset = ee.Image('JRC/GSW1_2/GlobalSurfaceWater');\n\nvar visualization = {\n bands: ['occurrence'],\n min: 0.0,\n max: 100.0,\n palette: ['ffffff', 'ffbbbb', '0000ff']\n};\n\nMap.setCenter(59.414, 45.182, 6);\n\nMap.addLayer(dataset, visualization, 'Occurrence');\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/JRC/JRC_GSW1_2_GlobalSurfaceWater) \n[JRC Global Surface Water Mapping Layers, v1.2 \\[deprecated\\]](/earth-engine/datasets/catalog/JRC_GSW1_2_GlobalSurfaceWater) \nThis dataset contains maps of the location and temporal distribution of surface water from 1984 to 2019 and provides statistics on the extent and change of those water surfaces. For more information see the associated journal article: High-resolution mapping of global surface water and its long-term changes (Nature, 2016) and ... \nJRC/GSW1_2/GlobalSurfaceWater, geophysical,google,jrc,landsat-derived,surface,surface-ground-water,water \n1984-03-16T00:00:00Z/2020-01-01T00:00:00Z \n-90 -180 90 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [](https://doi.org/https://global-surface-water.appspot.com)\n- [](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/JRC_GSW1_2_GlobalSurfaceWater)"]]
