Google Earth engine (GEE) - Global Human Settlements grid data 1975-1990-2000-2014 (p2016)

The GHSL relies on the design and implementation of new spatial data mining technologies allowing to automatically process and extract analytics and knowledge from large amount of heterogeneous data including: global, fine-scale satellite image data streams, census data, and crowd sources or volunteered geographic information sources.

The GHS-SMOD is the rural-urban Settlement classification MODel adopted by the GHSL. It is the representation of the degree of urbanization (DEGURBA) concept into the GHSL data scenario. Each grid in the GHS-SMOD has been generated by integrating the GHSL built-up areas and GHSL population grids data for reference epochs: 1975, 1990, 2000, 2015.

The DEGURBA classification schema is a people-based definition of cities and settlements: it operates using as main input a 1 km² grid cell accounting for population at a given point in time. The DEGURBA discriminates the population grid cells in three main classes: 'urban centers' (cities), 'urban clusters' (towns and suburbs), and 'rural grid cells'. (base). These class abstractions translate to 'high density clusters (HDC)', 'low density clusters (LDC)', and 'rural grid cells (RUR)', respectively, in the GHS-SMOD implementation.

The 'HDC' differ from the DEGURBA 'urban centers' in that they account for the over-fragmentation of cities in regions with large low-density residential development by integrating the built-up layer. In the GHS-SMOD representation, the 'HDC' are the spatial generalization of contiguous population grid cells (4-connectivity, gap-filling) with a density of at least 1500 inhabitants per km² or a density of built-up surface > 50%, and a minimum total resident population of 50000. The 'LDC' are continuous grid cells with a density of at least 300 inhabitants per km² and a minimum total population of 5000. The 'RUR' are grid cells outside 'HDC' and 'LDC' with population > 0 and < 300. Everything else is classified as inhabited areas where population = 0.

This dataset was produced in the World Mollweide projection (EPSG:54009).

For more information visit: Global Human Settlement - GHS SETTLEMENT GRID - European Commission.

The Global Human Settlement Layer (GHSL) project is supported by the European Commission, Joint Research Center, and Directorate-General for Regional and Urban Policy. The GHSL produces new global spatial information, evidence-based analytics, and knowledge describing the human presence in the planet.

GHSL It depends on the design and implementation of new spatial data mining technology , Allow automated processing and extraction of analysis and knowledge from large amounts of heterogeneous data , These data include ： The global 、 Fine scale satellite image data stream 、 Census data and population sources or voluntary geographic information sources .

GHS-SMOD yes GHSL Adopted urban and rural settlement classification model . It is the degree of urbanization ( DEGURBA ) Concept in GHSL Representation in data scenarios .GHS-SMOD Every grid in is integrated GHSL Built up areas and GHSL Population grid data generation , For reference periods ：1975、1990、2000、2015.

DEGURBA The classification model is based on the definition of human cities and settlements ： It USES 1 Square kilometer grid cells are used as the main input to calculate the population at a given point in time .DEGURBA The population grid cells are divided into three main categories ：“ City Center ”（ City ）、“ Urban agglomeration ”（ Towns and suburbs ） and “ Rural grid cells ”.（ according to ）. stay GHS-SMOD In the implementation , These class abstractions are transformed into “ High density cluster (HDC)”、“ Low density cluster (LDC)” and “ Rural grid cells (RUR)”.

“HDC” And DEGURBA Of “ City Center ” The difference is that , They explain the excessive fragmentation of cities with large low-density residential development areas by integrating built-up floors . stay GHS-SMOD In the middle ,“HDC” Is a continuous population grid cell （4 Connectivity , Gap filling ） Spatial generalization of , Its density shall be at least per square kilometer 1500 Density of residents or building surface > 50% , The minimum total resident population is 50000.“LDC” Is a continuous mesh cell , The density shall be at least per square kilometer 300 Residents , The minimum total population is 5000.“RUR” yes “HDC” and “LDC” Grid cells outside ' Population > 0 And < 300. Everything else is classified as population = 0 The residential area of .

The dataset is in World Mollweide Projection (EPSG:54009) Generated in the .

For more information , Please visit ： http: //ghsl.jrc.ec.europa.eu/ghs_smod.php.

Global human settlements layer (GHSL) The project was approved by the European Commission 、 Support from the joint research centre and the regional and Urban Policy Directorate .GHSL Generate new global spatial information 、 Evidence based analysis and description of the knowledge of human existence on earth .

The resolution of the
1000 rice

Band

full name	describe
smod_code	Degree of Urbanization

smod_code Class table

value	Color	describe
0	000000	Residential area
1	448564	RUR（ Rural grid cells ）
2	70daa4	LDC（ Low density cluster ）
3	ffffff	HDC（ High density cluster ）

Terms of use

GHSL from EC JRC As open and free data production . Authorize reuse , The premise is to confirm the source . For more information , Please read the conditions of use （ European Commission reuse and copyright notice ）.

Code ：

var dataset = ee.ImageCollection('JRC/GHSL/P2016/SMOD_POP_GLOBE_V1')
                  .filter(ee.Filter.date('2015-01-01', '2015-12-31'));
var degreeOfUrbanization = dataset.select('smod_code');
var visParams = {
  min: 0.0,
  max: 3.0,
  palette: ['000000', '448564', '70daa4', 'ffffff'],
};
Map.setCenter(114.96, 31.13, 4);
Map.addLayer(degreeOfUrbanization, visParams, 'Degree of Urbanization');

Citations:

• Pesaresi, Martino; Freire, Sergio (2016): GHS Settlement grid following the REGIO model 2014 in application to GHSL Landsat and CIESIN GPW v4-multitemporal (1975-1990-2000-2015). European Commission, Joint Research Centre (JRC) [Dataset] PID: Joint Research Centre Data Catalogue - GHS-SMOD R2016A - GHS settlement grid, following t... - European Commission