Yi-Fan Li Yi-Fan Li (1)(1) and Ashbindu Singh and Ashbindu Singh (2)(2) (1) (1) Air Quality Research Branch, Meteorological Air Quality Research Branch, Meteorological Service of Canada, Environmental CanadaService of Canada, Environmental Canada(2) (2) UNEP/GRID-Sioux Falls, EROS Data Centre, UNEP/GRID-Sioux Falls, EROS Data Centre, Sioux Falls, SD 57198, USASioux Falls, SD 57198, USA

Methodologies of Creation of Gridded Methodologies of Creation of Gridded Global Population Datasets for 1990 Global Population Datasets for 1990 and Their Applications in Compilation and Their Applications in Compilation of Gridded Emission Inventories for of Gridded Emission Inventories for Different PollutantsDifferent Pollutants

Introduction

In 1996, with financial support from the United Nations Environment Programme (UNEP), Environment Canada has created a population database depicting the worldwide distribution of population for 1990 with a 1X1 latitude/longitude resolution;

Over 75,000 registered users have accessed or downloaded the datasets from UNEP/GRID website since the data was released.

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Methodology Point sources: city population

• Around 6,000 cities and their populations from Rand McNally World Atlas

Area sources• 90,000 cities and towns as surrogate data • global rural population distribution factor

Population data for United States, Canada, China, and the former Soviet Union were replaced by better census datasets

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Global city population in 1990 Around 6,000 cities with population > 50K

inhabitants (with some exceptions) are located in the grid cells;

For cities with data from earlier than 1985, a growth rate of 0.63 are applied in developed countries, and 2.13 for those in less developed countries;

Then the average annual urban growth rate from UN for different countries are used to transfer city population of 1985-1989 to values of 1990.

City population in 1990 with 1 x1 lat/long resolution

Global rural population distribution factor for 1990

Around 20,500 major cities and 69,000 minor cities from 223 countries were allocated to 12,200 grid cells;

Population factors were assigned to each city: 2 for each major city, and 1 for each minor city;

The assigned population factors in each grid cell were summed up for each country, and a rural population distribution factor dataset for 1990 with 1X1 degree latitude/longitude resolution was obtained.

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Global residence area with 1 x1 lat/long resolution

Global rural population distribution

The total “rural” population was obtained by subtracting the global city population in 1990 from the total of national populations for 1990. This total “rural” population was allocated to grid cells according to the formula:

Pop. factor in the cell for the country

Rural pop in cell = Total rural population X Total pop. factor for the country

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Refinement of the Dtataset:

The data for the following countries are replaced by better datasets.

United States Census Data• Two 1990 census population datasets for approximately 23,400 USA

cities and 3,141 counties were used. Canadian Data

• A gridded Canadian population dataset for 1991 with a 1/6 latitude and 1/4 longitude grid resolution was obtained from the Canadian National Pollutant Release Inventory, and scaled to 1990 for each grid by a factor of 26,647/27,297 (Canadian population for 1990 is 26,647,000, for 1991 is 27,297,000).

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Refinement of the Dtataset (Ctn.):

Chinese Population Data• The Chinese 1990 census data, which contains population data for 2,405

administration units (cities and counties), were allocated over the cities and county capitals.

Former Soviet Union Data• The 1990 population data for 15 former USSR republics were obtained from

Dr. Alexey G. Ryaboshapko, Institute of Global Climate and Ecology, Moscow, Russia. City and town population figures were allocated to each cell according to its latitude and longitude. The rural population was determined separately for each county (raion) in Russia, and for each province (oblast) in other former Soviet Republics.

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Gridded Global Population Datasets for 1990Gridded Global Population Datasets for 1990

The 1990 global population dataset contains 16,762 records and covers 209 countries and 11,748 grid cells about 1.8% of the total 648,000 grid cells worldwide. The population of the countries in the database is 5.291 billion, within 0.07% of the FAO’s total estimated world population for 1990, of 5,295 billion.

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Global population for 1990 with 1 x1 lat/long resolution

Applications in Compilation of Gridded Emission Applications in Compilation of Gridded Emission Inventories for Different PollutantsInventories for Different Pollutants

Gridded population data are a very important surrogate for distributing area sources of a large amount of pollutants;

This database has been accepted as the standard population data by Global Emissions Inventory Activities (GEIA), a component of the International Global Atmospheric Chemistry core project of the International Geosphere - Biosphere Program;

GEIA Website: http://www.geiacenter.org

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Selected Publications in which the population data Selected Publications in which the population data were used as surrogatewere used as surrogate

Li, Y. F., Zhang, Y. J., Cao, G. L., Liu, Jian Hui, and Barrie, L.A., 1998, “Distribution of seasonal SO2 emissions from fuel combustion and industrial activities in Shanxi, China, with 1/6o X 1/4o longitude/latitude resolution”, Atmospheric Environment, 33, 257-265.

Pacyna, J. M., Scholtz, M. T., and Li, Y. F., 1995, “global budget of metal sources”, Environmental Reviews, Vol. 3, 145-159.

Brook, Jeffery, Zhang, Leiming, and Li, Yi-Fan, 1999, “Modelling of dry deposition velocities on local and regional scales. Part II: Modelled dry deposition over south-eastern Canada” Atmospheric Environment, 33, 5053-5070

McCulloch, A., M. Aucott, C.M. Benkovitz, T.E. Graedel, G. Kleiman, P.M. Midgley, Y.F. Li, 1999, “Global emissions of hydrogen chloride and chloromethane from coal combustion, incineration and industrial activities: the Reactive Chlorine Emissions Inventory”, J. Geophys. Res., 104, D7, 8391-8403

Aucott, M., A. McCulloch, T. E. Graedel, G. Kleiman, P. M. Midgley, and Y.F. Li, 1999, “Anthropogenic emissions of trichloromethane (chloroform, CHCl3) and chlorodifluoromethane (HCFC-22): Reactive Chlorine Emissions Inventory”, J. Geophys. Res., 104, D7, 8405-8415

Selected Publications in which the population data Selected Publications in which the population data were used as surrogatewere used as surrogate

McCulloch, A., M. L. Aucott, T. E. Graedel, G. Kleiman, P. Midgley, and Y.F. Li, 1999, “Industrial emissions of trichloroethene, tetrachloroethene, and dichloromethane: The Reactive Chlorine Emissions Inventory”, J. Geophys. Res., 104, D7, 8417-8427

Keene, William C., M. Aslam K. Khalil, David J. Erickson, III, Archie McCulloch, Thomas E. Graedel, Michael L. Aucott, Sun Ling Gong, David B. Harper, Gary Kleiman, Valentine Koropalov, Jurgen M. Lobert, Pauline Midgley, Robert M. Moore, Christophe Seuzaret, William T. Sturges, Len A. Barrie, Jennifer A. Logan, Y.F. Li, 1999, “Composite global emissions of reactive chlorine from anthropogenic and natural sources: The Reactive Chlorine Emissions Inventory”, J. Geophys. Res., 104, D7, 8429-8440

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Financial support from Environment Canada Financial support from Environment Canada and UNEP made this work possible;and UNEP made this work possible;

Thanks also to Dr. Alexey G. Ryaboshapko, Thanks also to Dr. Alexey G. Ryaboshapko, Institute of Global Climate and Ecology, Institute of Global Climate and Ecology, Moscow, Russia for providing population data of Moscow, Russia for providing population data of former Soviet Union;former Soviet Union;

Comments sent to us by many users of the data Comments sent to us by many users of the data are highly appreciated.are highly appreciated.

AcknowledgmentsAcknowledgments