Enumeration Area Demarcation (EAD)

WHAT IS EAD?
EAD is the process of dividing the entire country into smaller units with clearly defined and identifiable boundaries, called Enumeration Areas (EAs). This is done in such a manner that there is no overlap or gap between them. The EAs so produced becomes the assignment map which determines enumerator’s workload during Censuses and Surveys. It is an area which an enumerator will effectively cover without any omission or duplication during a census or sample survey.
The EAD for 2022 Census is the fourth time pre-census mapping was carried out prior to a census in Nigeria, the others being for the 1973, 1991 and 2006 Censuses. However, the 2022 Census EAD is unique in a number of ways because it was the first time, the entire country was demarcated using Geographic Information System (GIS) methodology. Further, a customized application (EADPad) was developed which integrated both the spatial dataset and forms for collecting attribute data on the same platform. These innovations made it possible to achieve a sustainable national geographic frame for Censuses and Surveys.
The EAD exercise was conducted by the Cartography Department, with the collective involvement of all other Departments in the Commission. The Census Department handled the Quality Assurance component of the exercise; the ICT Department configured, profiled and monitored the Personal Digital Assistants used for the field exercise; the Legal Department provided the legal framework to guide the conduct of functionaries and maintain the confidentiality of data collected on the field; Planning and Research Department managed the monitoring and evaluation component; Human Resources and Administration Department provided administrative/secretarial assistance during trainings and workshops; the Public Affairs Department handled advocacy and publicity; and the Finance and Accounts Department disbursed funds to functionaries and other financial duties.
The 2022 Census EAD provided a range of geo-spatial datasets which are useful for data collection, analysis and dissemination of information. They are also beneficial to several other sectors including agriculture, health, defense, education, communication and energy, as well as for e-governance and the allocation of services and amenities.
The datasets from EAD include Enumeration Area (EA), Supervisory Area (SA), Locality, Registration Area (RA)/Ward and Local Government Area (LGA) spatial and attribute data. Others are information on all buildings in the country, their types and distribution by Wards, Localities, LGAs and States. Also, information on roads and streets, water bodies, infrastructure and distribution of households in the RA/wards, localities, LGAs and States are made available. These are available to researchers and other users at a cost, a veritable source of revenue generation for the Government.

EAD METHODOLOGY
The methodology for the Census 2022 EAD was based on Geographic Information System (GIS). GIS can be defined as an organized system of computer hardware, software, procedures and personnel designed to support the capture, management, manipulation, analysis and display of spatially referenced data for solving planning and management problems. In a nutshell, GIS is an automated information system that is able to compile, store, retrieve, analyze, and display mapped data which are spatially referenced to the earth.
The methodology for the Census 2022 involves the following stages:

(a) Pre-field – Creation of Initial Database
(b) Field – Data Acquisition
(c) Post Field – Data Processing and Output

The following figure shows the three stages of EAD methodology.

PHASES IN THE EAD FOR 2022 CENSUS
EAD for Census 2022 started with a Pilot Phase from the 1st to 11th of December 2014 at Akoko South-East LGA in Ondo State. Despite the initial plan to execute the EAD over a 3-year period, it went on for 7 years due to inadequate timely funding especially at the initial stage. There was however tremendous improvement towards the end of 2019 when more funds were released by the Federal Government. This accelerated the pace of the exercise from Phase 11 to Phase 17 spanning a 10-month period until completion in November 2021. It was therefore completed in 18 Phases.

BENEFITS OF EAD
The following benefits are derived from the EAD.
1. EAD helps in determining the workload of the enumerator and the supervisor during censuses and surveys, the EAs being essentially enumerators assignment maps. It further ensures that there is proper assessment of the workload before allocation to enumerators.
2. EAD product makes field monitoring and supervision very easy, through the aggregation of EAs to form Supervisory Areas (SAs) through to the LGAs and States, with various levels of supervision.
3. EAD ensures total coverage during censuses, allocating enumerators sets of mutually exclusive and non-overlapping areas, thereby covering exhaustively the entire land area of the country and thus eliminating errors of coverage.
4. EAD provides a basis for checking the accuracy of the data thus obtained, and permits an oversight to be spotted quickly.
5. EAD also facilitates monitoring of changes within a given area and over a given period, and comparison between distinct areal units. In this way, local and regional variations of population size and composition will be depicted. It will also be easy to engage in demographic analysis of geographic variation in elements of population dynamics.
6. Post-census demographic and other spatial analysis for decision making is accentuated by EAD products. This is possible because EAs are based on a national frame, and EA boundaries lie entirely within a well-known administrative boundary. Thus, the results of census or any socio-economic survey can be validated factually.

CONCLUSION

The conduct of any successful census must necessarily begin with (and be based on) functional maps produced during the EAD. This makes it possible to locate the population to be enumerated and their dwelling units accurately and correctly, assess the total workload, ensure complete coverage, plan adequately for monitoring and supervision of field activities, and graphically display the final result for better understanding. Thus, the success of the 2022 national population and housing census enumeration hinges on the success of the EAD.