The Generalised Settlement Area: mapping the Earth surface in the vicinity of built-up areas

Figures & data

Figure 1. Comparison of the products approximating human settlement and built-up surfaces (a), and the resultant settlement masks (b).

Table 1. Main characteristics of products used in the analysis.

P	D	R	MT [T/LC]	EO-s [O/R]	PC	RR	ID
MODIS 2002v5 Urban	2002	463 m	T	MODIS [O]	Urban and built-up area	10 m	Modis
GRUMP v1 Urban Extent Polygons, v1.0	1995	927 m	T	DMSP-OLS [O]	Urban extent	10 m	Grump
ESA Climate Change Initiative Land Cover v2.0.7	2015	300 m	LC	PROBA-V [O]	Urban areas	10 m	EsaCCI
GlobeLand30 2010	2010	30 m	LC	Landsat [O]	Artificial surfaces	1 m	Glc30
HBASE 2010	2010	30 m	T	Landsat [O]	Built-up And Settlement Extent	1 m	Hbase
GHS Landsat Built-up area, 2017 (*)	2014	30 m	T	Landsat [O]	Built-up area	1 m	GhsLds
GHS Sentinel 1 Built-up, 2016 (*)	2015	∼19 m	T	Sentinel 1 [R]	Built-up area	1 m	GhsS1
Global Urban Footprint 2012	2012	12 m	T	TerraSAR-X/ TanDEM-X [R]	Urban footprint	2 m	Guf12

Note: P – product designation (*some products are planned as public release in 2019); D – reference date of the layer used in this analysis; R – spatial resolution expressed in metres at the equator in a native geographic projection; MT – map type [Thematic/LandCover]; EO-s – EO programme of the main data sources producing optical or radar products [O/R]; PC – semantic of the proxy settlement class; RR – resampling resolution; ID – acronym of the derived 1 km² mask).

Figure 2. Examples of agreement map centred on areas nearby: Amsterdam (Netherlands) (a), Cairo (Egypt) (b), and Tel Aviv (Israel) (c); Mwanza (Tanzania) (d), Doha (Qatar) (e), and Seoul (South Korea) (f); New Orleans (USA) (g) and Cuenca (Ecuador) (h).

Figure 3. Overview of the Generalised Settlement Area map.

Table 2. Global assessment of water, landmass and settlement space.

	kilometre square	% over landmass	% over water (lm)
Landmass	136,324,183
water (lm)	6,468,013	4.74%
Settlement space	19,482,480	14.29%
water (SttlSpc)	529,100	0.39%	8.2%

Figure 4. Overview of the share of the agreement class within the Generalised Settlement Area map (a), and the share of the water accounted in each agreement class.

Table 3. Settlement mask (SttlMsk) general statistics (AC1 – Agreement Class 1).

	SttlMsk			AC1
	Total (ths) km^2	% over landmass	% over SttlUniv	Total (ths) km^2	% over SttlMsk	share in SttlSpc AC1	share in SttlSpc
Modis	1307	1.0%	6.7%	109	8.4%	1.4%	0.31%
EsaCCI	2078	1.5%	10.7%	48	2.3%	0.6%	0.13%
Hbase	3106	2.3%	15.9%	153	4.9%	1.9%	0.43%
Grump	4457	3.3%	22.9%	958	21.5%	11.8%	2.69%
Glc30	5921	4.3%	30.4%	526	8.9%	6.5%	1.48%
GhsLds	8738	6.4%	44.9%	1672	19.1%	20.7%	4.70%
Guf12	9979	7.3%	51.2%	1264	12.7%	15.6%	3.55%
GhsS1	12,759	9.4%	65.5%	3355	26.3%	41.5%	9.43%
SttlSpc	35,586	14.29%	100%	8086	22.7%	100%	22.72%

Figure 5. Overview of the share of agreement class in each settlement mask.

Figure 6. Overview of the regional analysis. Total area of the Generalised Settlement Area (GSA) per UN Region in km² (a), the share of the agreement class within each region (b), and the absolute surface of each settlement masks per region (c).

Figure 7. Refined regional analysis of the Generalised Settlement Area (GSA) map: the total surface of the GSA per region in km² (a); the share of the GSA within surface of each region (b); and the average population density per region (PD/Lm) and GSA (PD/GSA) surfaces depicted in violet and brown colour, respectively (c). An additional division of the Easter Europe region has been made (marked by (*) symbol) to identify the Russia contribution.