national administrative department of statistics dane...

@DANE_Colombia /DANEColombia /DANEColombia

National Administrative Department of Statistics –DANE

Colombia

October 2015

Using satellite images to calculate land use and land cover

statistics

Background (1)

Objective

• Explore the usefulness of Big Data from satellite land images for theupdating and improvement of statistic information.

• Calculate an indicator that shows the urban agglomeration degree by usingsatellite images and population data.

• This indicator would provide additional information to the framework forthe implementation of several goals referred to in health and food security.

Data collection

Changesdetection

Ratescalculation

Indicatorcalculation

Satelliteimagescollection

Populationdata collection

Image pre-processing

Imageclassification

Populationgrowth rate

Urban landconsumptionrate

Ratio of therates

Methodology

Imagery collection

Landsat 2005 Landsat 2010Landsat 2015

Criteria:

• Availability

• Quality (percentage of cloud cover)

• Acquisitions at the same time of the year

• Spatial coverage

• Similar spectral bands

http://earthexplorer.usgs.gov/

Imagery pre-processing

Original 2005 Image Pre-processed image

Semantic net

Rules and operatorsdefinition

Coveragesgeneration

Coverages generation with object-oriented classification

Coverage map

Water

Urban/Built - Up

Grassland

Barren/Minimal Vegetation

Forest, Shrub and Scrubland

Coverage map 2005Coverage map 2010Coverage map 2015

Map Legend

Approach to the Land Consumption Rate (ULCR)

)(

)( )(

1

12

tAreaLandUrban

tAreaLandUrbantAreaLandUrbanLCR

10.807

11.288

12.178

2005 2010 2015

Barranquilla Metropolitan Area

Urban hectares

8%4%

Approach to the Population Growth Rate (PGR)

)(

)()(

1

12

tPopulation

tPopulationtPopulationPGR

1,769,191

1,898,007

2,025,071

2005 2010 2015

Barranquilla Metropolitan Area

Population

7%7%

*Population projections

* *

Proposed Indicator

RateGrowthPopulation

RatenConsumptioLandIIndicator )(

I=0.642005-2010 I=1.13

2010-2015

* *

* Preliminary data

• Big Data from satellite imagery is a powerful tool to increase thepotential applications of statistics and to improve the quality ofstatistics data. This integration allows the exploration of newmethodologies and the improvement of those already available.

• The benefits generated by the use of remote sensing, create theopportunity to make the information more traceable and allow thedesign of different types of multitemporal studies.

• This project is a good example for the use of open source software andsatellite images, which are both available on the web for free.

Comments

@DANE_Colombia /DANEColombia /DANEColombia

dig@dane.gov.cosyrodriguezf@dane.gov.co