PRESENTATION BY STATISTICS SIERRA LEONE ON THE USE OF GPS TO DESIGN ENUMERATION

AREAS: A CONVENIENT SOLUTION FOR DEVELOPING NATIONAL SAMPLING FRAMES

GEOGRAPHY OF SIERRA LEONE

• GEOGRAPHIC COORDINATES

8 30 E, 11 30 W

AREA 71,740 SQ KM

POPULATION 4,976,871

(2004 CENSUS)

CLIMATE DRY SEASON DEC-APR

WET SEASON MAY-DEC

NATURAL

RESOURCES

DIAMOND,TITANUM ORE,BAUXITE,IRON ORE,GOLD,CHROMITE.

DATA COLLECTION

• Georeferencing of urban and rural maps at scales of 1:25,000 and 1:50,000 respectfully.

• Printing of maps with UTM co-ordinates for use in the field.

• Collection of GPS (Garmin 12) co-ordinates of the following

1. Localities

2. Administrative boundaries

3. Educational institutions

4. Health facilities

5. Other social facilities eg. Churches,mosques etc.

DATA CAPTURE

• Fair drawing and demarcation of enumeration areas and administrative boundaries using GPS co-ordinates and natural features.

• Data entry of GPS co-ordinates using excel

• Conversion of GPS co-ordinates into dbase iv for processing in Arcview

• Scanning of map sheets using AO scanner.

• On-screen digitization of administrative boundaries down to EA level.

• Editing and cleaning of EA shapefile using ArcEditor.

• Linking of census database to EA shapefile for analytical planning with respect to health,education,agriculture etc.

ATTRIBUTE DATA OF AN EA

CHIEFDOM SECTION EA NO LOCALITY UTM EASTINGS

UTM NORTHINGS

DEA BAIWALLA 01010101 TAMBEYAMA 1 316971 886981

TAMBEYAMA 2 316529 887357

JORU 317538 883776

NYANDEHUN 318742 884528

POINT DATA OF ENUMERATION AREAS

DIGITIZED EA DATA BASE (9,671 EA’S)

CENSUS DATA LINKED TO EA SHAPE FILE

EA NO. DIST DIST.CODE

CDOM CDOM CODE

SEC SEC.CODE

MALE FEMALE TOT.POP H/H

11010101 KAILAHUN

11 1101 DEA BAIWALLAH

110101 126 149 275 68

11010102 KAILAHUN

11 1101 DEA BAIWALLAH

110101 182 244 426 96

11010103 KAILAHUN

11 1101 DEA BAIWALLAH

110101 197 231 428 89

11010104 KAILAHUN

11 1101 DEA BAIWALLAH

110101 192 203 395 72

USE OF EA DATA BASE

• National sampling frame

• Delimitation of electoral wards

• Reproduction of constituency maps

• Reproduction of administrative maps (District,chiefdom and sections)

• Spatial distribution of health and educational facilities

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