Population estimation and census track demarcation in Hwolshe, Plateau State, Nigeria: A geospatial approach

Abstract

The conventional and cumbersome method of demarcating census enumeration area (EA) has been characterized with several delineation challenges. These challenges include under/over-estimation of population figures, very tedious procedures and error-prone outcomes, as well as high exposure to forgery, owing to non-transparency of estimation designs and the culminating difficulty in validating the obtained census figures. This study therefore sought to improve on the obsolete and high error-prone approach by taking advantage of remotely sensed data and GIS technologies, exploring geospatial approach for population estimation and Census track demarcation in Hwolshe, Plateau State. QuickBird image (0.6 m spatial resolution) covering the study area was acquired and utilized for defining the enumeration areas. Individual dwelling units were also extracted and, the heights and sizes of shadows were used in categorizing all identified building types. The adopted categories in the area included: bungalow single-family; multi-household compound; one-floor storey building; single-household and one-floor storey buildings for multi-household. Field survey using GPS was engaged in establishing EA location. Demographic data was also put to use for population estimation based on the dwelling units. The total number of buildings was multiplied by average number of household (H/H) and the average H/H size to get the total population estimate. From the implemented analysis, bungalow single-family was seen to represent 29% of the total estimated population; whereas Multi-H/H compound accounted for 57%; one-floor storey building single H/H 2% and one-floor storey building multi-H/H jointly constituted for 10% of the total population. In all the method realized about 98% accuracy for the enumeration exercise. The old and new EA maps were compared through context analysis. This work proved to be more efficient, guaranteeing better coverage of the study area, as well as depiction of a scientific for regulating under/over-counting as evidenced by transparency the remotely sensed data and the adopted GIS tools. This work recommends that the potentials and efficiency of geospatial technique be explored to review Census EAs and population estimation in Nigeria.