The relationship between grid cells and countries

Metadata:

• Identification_Information
• Spatial_Data_Organization_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Yi-Fan Li, Environment Canada

Publication_Date: 19960812

Title: The relationship between grid cells and countries

Geospatial_Data_Presentation_Form: diagram

Publication_Information:

Publication_Place: Downsview, Ontario M3H 5T4, Canada

Publisher: Environment Canada

Online_Linkage: <http://grid.cr.usgs.gov/clearinghouse/datalist.html>

Description:

Abstract:

This project has provided a population database depicting the worldwide distribution of population in a 1X1 latitude/longitude grid system. The database is unique, firstly, in that it makes use of the most recent data available (1990). Secondly, it offers true apportionment for each grid cell that is, if a cell contains populations from two different countries, each is assigned a percentage of the grid cell area, rather than artificially assigning the whole cell to one or the other country (this is especially important for European countries). Thirdly, the database gives the percentage of a country's total population accounted for in each cell. So if a country's total in a given year around 1990 (1989 or 1991, for example) is known, then population in each cell can be calculated by using the percentage given in the database with the assumption that the growth rate in each cell of the country is the same. And lastly, this dataset is easy to be updated for each country as new national population figures become available.

Purpose:

Population databases are forming the backbone of many important studies modelling the complex interactions between population growth and environmental degradation, predicting the effects of global climate change on humans, and assessing the risks of various hazards such as floods, air pollution and radiation. Detailed information on population size, growth and distribution (along with many other environmental parameters) is of fundamental importance to such efforts.

Supplemental_Information:

GridCtry.dbf: The relationship between grid cells andcountries
Fields: - Grid           Grid code number
           - Cover-Id    Cover ID Number	
                              "0":  All covered by sea
                              "1":  Entirely contained
                                      in one country
                              "2":  Shared by two countries
                              "3":  Shared by three countries
                              "4":  Shared by four countries
                              "10": Shared by one country and ocean
                              "20": Shared by two countries and ocean
                              "30": Shared by three countries and ocean
                              "40": Shared by four countries and ocean					
           - UNCode2  United Nations standard ISO country codes	
           - Country      Country/region name	
           - Rate-in-Country (%)	Percentage of the area of a country 
                                                contained in each grid cell
           - Rate-in-Grid (%)      Percentage of the area of the grid cell 
                                           occupied by country or the ocean
Number of Records            25,540
Number of Cells:                 12,200
Total Number of Countries: 217
Definition of Grid Code Number
Grid Code Number = (j*1000) + i 
j: row number starting at 1 for 90�S to 89�S latitude, to 180 for 89�N to 90�N latitude 
i: column number starting at 1 for 180�W to 179�W longitude, to 360 for 179�E to 180�E longitude 
The latitude and longitude of the centre of the grid cell is given by 
latitude = (j-91) + 0.5 
longitude = (i-181) + 0.5

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 19900101

Ending_Date: 19901231

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: Unknown

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -180

East_Bounding_Coordinate: 180

North_Bounding_Coordinate: 90

South_Bounding_Coordinate: -90

Keywords:

Theme:

Theme_Keyword_Thesaurus: None

Theme_Keyword: population

Theme_Keyword: country

Theme_Keyword: grid cell

Theme_Keyword: relationship

Temporal:

Temporal_Keyword_Thesaurus: None

Temporal_Keyword: 1990

Access_Constraints:

The GRID database is maintained for the purpose of assisting individual nations and the international community in making sound decisions related to resource management and environmental planning, and where applicable providing data for scientific studies. In general, requests for data from the archive will be filled according to data availability, GRID workload and the nature of the data set being requested. Requests will be queued with priority given to requests related to joint activities with UNEP programme areas. UN organizations, intergovernmental organizations, scientific and academic organizations, non-governmental organizations are all eligible to request data from the GRID archive. Requests from eligible organizations for data with unrestricted access rating will normally be filled without further clearance. Requests for data with a source approval rating will be referred to the relevant authority for clearance, and in some cases, the requestor will be advised to seek the data from the source. Data sets with an in-house rating will not be distributed; however, information about such data sets, including the distributor's name, will be sent to eligible organizations on request. Data requests from private commercial firms and private individuals will not be filled. Exceptional cases in which the intended use of the data would be of direct benefit to the United Nations or member states will be considered on a case-by-case basis by the GRID Director, in consultation with the UNEP Assistant Executive Director-Programme.

Use_Constraints:

Users of datasets supplied through GRID are requested to incorporate in output products and reports acknowledgments to the originator of the data and to the fact that they were acquired through GRID. Appropriate wording may be "UNESCO(1987) through GRID".

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Distribution_Information:

Distributor:

Contact_Information:

Contact_Person_Primary:

Contact_Person:

Contact_Organization: UNEP/GRID-Sioux falls

Contact_Address:

Address_Type: mailing and physical address

Address:

UNEP/GRID-Sioux Falls EROS Data Center U.S. Geological Survey

City: Sioux Falls

State_or_Province: South Dakota

Postal_Code: 57198

Country: USA

Contact_Voice_Telephone: 605-594-6107

Contact_Facsimile_Telephone: 605-594-6119

Contact_Electronic_Mail_Address: [email protected]

Resource_Description:

GridCtry.dbf: The relationship between grid cells and countries

Distribution_Liability:

Metadata_Reference_Information:

Metadata_Date: 19981201

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person:

Contact_Organization: UNEP/GRID-Sioux falls

Contact_Address:

Address_Type: mailing and physical address

Address:

UNEP/GRID-Sioux Falls EROS Data Center U.S. Geological Survey

City: Sioux Falls

State_or_Province: South Dakota

Postal_Code: 57198

Country: USA

Contact_Voice_Telephone: 605-594-6107

Contact_Facsimile_Telephone: 605-594-6119

Contact_Electronic_Mail_Address: [email protected]

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998