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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