October 2021

Global 1-km Downscaled Urban Land Extent Projection and Base Year Grids by SSP Scenarios, v1 (2000-2100)


PURPOSE

To provide global SSP-consistent spatial urban land projections and base year grids based on the Shared Socioeconomic Pathways (SSPs) data at a resolution of 1-km (about 30 arc-seconds) for climate, socioeconomic, environmental, and other related research.


DESCRIPTION

The Global 1-km Downscaled Urban Land Extent Projection and Base Year Grids by SSP Scenarios, 2000-2100 consists of global SSP-consistent spatial urban land fraction data for the base year 2000 and projections at ten-year intervals for 2010-2100 at a resolution of 1-km (about 30 arc-seconds). An algorithm was developed and validated to downscale the 1/8-degree resolution data set to 1-km resolution. For a given decade, the downscaling algorithm allocates the 1/8-degree decadal amount of urban land expansion to 1-km grid cells in proportion to their total urban land amounts at the beginning of the decade. The algorithm uses an iterative process to collect any overflows from already highly-developed 1-km grid cells, and then allocates them to 1-km grid cells that are not yet fully developed. This iterative process repeats itself until all 1/8-degree amounts of urban land expansion are allocated to 1-km grid cells with no overflow. The downscaling process is applied decade by decade throughout the 21st century for each urban land expansion scenario. The final product is a set of global maps displaying the 1-km fraction of urban land, updated at decadal intervals throughout the 21st century, for five different urban land expansion scenarios consistent with the Shared Socioeconomic Pathways (SSPs).


ACCESSING THE DATA

The data may be downloaded at https://sedac.ciesin.columbia.edu/data/set/ssp-1-km-downscaled-urban-land-extent-projection-base-year-ssp-2000-2100/data-download


DATA FORMAT

This archive for the Base Year 2000 contains gridded data in GeoTIFF and netCDF formats.

This archive for the Projections 2010-2100 contains gridded data in GeoTIFF and netCDF formats.

This archive for the Ancillary Layers contains gridded data in GeoTIFF and netCDF formats

The data files are compressed zipfiles. Downloaded files need to be uncompressed in a single folder using either WinZip (Windows file compression utility) or similar application. Users should expect an increase in the size of downloaded data after decompression. 


DATA VALUES

Data values are in fraction of urban land.


SPATIAL EXTENT

Global 1-km (about 30 arc-seconds).


DISCLAIMER

CIESIN follows procedures designed to ensure that data disseminated by CIESIN are of reasonable quality. If, despite these procedures, users encounter apparent errors or misstatements in the data, they should contact SEDAC User Services at ciesin.info@ciesin.columbia.edu. Neither CIESIN nor NASA verifies or guarantees the accuracy, reliability, or completeness of any data provided. CIESIN provides this data without warranty of any kind whatsoever, either expressed or implied. CIESIN shall not be liable for incidental, consequential, or special damages arising out of the use of any data provided by CIESIN.


USE CONSTRAINTS

Users are free to use, copy, distribute, transmit, and adapt the work for commercial and non-commercial purposes, without restriction, as long as clear attribution of the source is provided.


RECOMMENDED CITATION(S)

Data Set:

Gao, J. and M. Pesaresi. 2021. Global 1-km Downscaled Urban Land Extent Projection and Base Year Grids by SSP Scenarios, 2000-2100. Palisades, NY: NASA Socioeconomic Data and Applications Center (SEDAC). https://doi.org/10.7927/1z4r-ez63. Accessed DAY MONTH YEAR. 

Scientific Publication:

Gao, J. and M. Pesaresi. 2021. Downscaling SSP-consistent Global Spatial Urban Land Projections From 1/8-degree to 1-km Resolution 2000-2100. Scientific Data. https://doi.org/10.1038/s41597-021-01052-0.