Green areas - Copernicus · for rural green areas and monitoring land consumption. Sentinel 2 are...

Copernicus EU

Copernicus EU www.copernicus.eu

Copernicus EU

Copernicus Training and Information Session

10 and 11 may 2017 in Lund, Sweden

Green areas: numerous positive effects for sustainable metropolisSatellite images : an easy way to map vegetation

Dominique HEBRARD

Land Monitoring

Urban Heat Island

“Through the Urban Agenda for the EU, national governments, the European Commission, European institutions and other stakeholders will be working together for a sustainable, innovative and economically powerful Europe that offers a good quality of life.”http://urbanagendaforthe.eu

The green areas contribute of the quality of life for urban inhabitants.

Urban Agenda for the EU

Urban Agenda for the UE

U r b a n a g e n d a f o r t h e E U

Land Monitoring

The followings positive effects should be taken into account :

Green areas benefits are numerous

- limitation of floods- biodiversity conservation policies- inhabitant well-being and positive impacts on health- urban quality- cooling effect (urban heat island)

B e n e fi t s o f g r e e n a r e a s a r e n u m e r o u s

Land Monitoring

The Urban vegetation is usually not well known in the current database especially in the private areas. It’s an important lack of data for the public policies makers who need Inventory of the situation of their metropolis. They need also data to asses the efficiency of the strategies implemented.

K n o w l e d g e o f g r e e n a r e a s f o r u r b a n p l a n n e r s

Land Monitoring

Most of the optical earth observation satellites have sensors that are able to map the vegetation.

How satellite images can contributeto the knowledge of green areas ?

Vegetation is characterized by

- high absorbtion on the red - low absorption on Near Infrared.

H o w s a t e l l i t e d a t a c a n c o n t r i b u t e t o t h e k n o w l e d g e o f g r e e n a r e a s ?

Land Monitoring

A simple vegetation indicator called NDVI (Normalized Difference Vegetation Index) enables to map in a simple way the vegetation.

NIR : Near Infra-Red bandRED : Red Band

NDVI = NIR - REDNIR + RED

J. W. Rouse. “Monitoring the vernal advancement and retrogradation of natural vegetation,”Type ii report, NASA/GSFCT, Greenbelt, MD, USA, 1973. 12.1.1

lRVI (Ratio Vegetation Index) l RVI = NIR / RED

lDVI (Difference Vegetation Index) DVI = NIR - RED

l…..

Other vegetation index combining RED and NIR exist as :

H o w s a t e l l i t e d a t a c a n c o n t r i b u t e t o t h e k n o w l e d g e o f g r e e n a r e a s ?

Land Monitoring Of course channels red and infra-red are needed, but the resolution is

also a key issue.

Very High Resolution images are the best solution to map the vegetation, especially at the cadastral parcel level. - Pleiades (50 cm) fit to this need for urban areas- Sentinel 2 have a lower resolution (10 m). This lower resolution can fit for rural green areas and monitoring land consumption. Sentinel 2 are easy to get and it’s possible to choose easily the best season.

The season for the selected image has to be adpated, depending on the local climate. (eg: in France it should be good to select an image between march and september)

W h i c h i m a g e a r e r e l e v a n t f o r g r e e n a r e a s ?

Land Monitoring

Copernicus sources for Vegetation mapping

Satellite data•Copernicus Contributing MissionsOptical missions with NIR and Red bands as Pléiades with Very High Resolution for urban areas, or RapidEye, SPOT with High Resolution ...

•Sentinel-2 missionFull constellation will provide image with NIR (band8) and RED (band4) about every day at 10-20m spatial resolution

Copernicus Land Monitoring servicesCopernicus Global Land Service provides access to Pan-european High Resolution Layers of Forests and grassland maps from 20m resolution satellite imagery updated every 3 years.

Copernicus sources for Green Areas

Land Monitoring

Using satellite data to map green areas

DEMONSTRATION

Use of very high resolution optical satellite data to have a global view of Green areas in urban context.

Land Monitoring

Demonstration

Data used:Pléiades image acquired the 05-MAR-2014, orthorectified

Software used for the demo:

Qgis software is usedFree and Open Source Geographic Information System

Sentinel Application Platform (SNAP) Free Toolboxes made available by ESA

can be used for similar manipulation with Sentinel2

Land Monitoring

Demonstration

> Open satellite dataDemonstration

Land Monitoring

Demonstration> Adapt radiometric parameters to see the landscape in true colors

Demonstration

Land Monitoring

Demonstration> Adapt radiometric parameters to see the landscape in true colors

Demonstration

Land Monitoring

> Zoom in the area of interestDemonstration

Land Monitoring

> NDVI computationDemonstration

Land Monitoring

> NDVI computation

=NDVI=(PIR-R)/(PIR+R)

Demonstration

Land Monitoring

> NDVI computationDemonstration

Land Monitoring

> Vegetation extractionDemonstration

Land Monitoring

> Vegetation layerDemonstration

Land Monitoring

> Vegetation layer : create a mask of vegetation

Mask=1 if NDVI>0.3

Demonstration

Land Monitoring

> Vegetation vector layerDemonstration

Land Monitoring

> Vegetation vector layerDemonstration

Land Monitoring

> Vegetation vector layerDemonstration

Land Monitoring

> Vegetation vector layerDemonstration

Land Monitoring

> Vegetation vector layerDemonstration

Land Monitoring

> Vegetation vector layerDemonstration

Land Monitoring

> Vegetation area estimationDemonstration

Land Monitoring

> Vegetation area estimationDemonstration

Land Monitoring

Outlook : a step towards more sophisticated products Contribution of Pléiades-HR images to the assessment of urban green infrastructures : dealing with urban ecological network issues and urban densification

Source : Pauline Crombette (LISST CIEU, CNES)

roughness coefficientVegetation : trees

Increase of the roughness ceof. Depending on the buidings and roads

Area with vegetation trees

ecological network

Land Monitoring

Thank you for your attention !

dominique.hebrard@cerema.fr