SOURCE:

Faculty: Environmental Sciences
Department: Surveying & Geo-informatics

CONTRIBUTORS:

Igbokwe, E. C.
Emengini, E. J.
Ojiako, J. C.

ABSTRACT:

Monitoring development is an essential part of assessing current development trends with a view of improving urban quality of life in the future as growth affects man and his environment adversely.Urban development prediction has acquired an important consideration in urban sustainability; an effective approach of urban prediction can be a valuable tool in urban planning and decision making. This study therefore investigated the development dynamics of Awka Capital Territory in Anambra State using Remote Sensing and Prescott Spatial Growth Model. The objectives were to: examine the spatial extent of landcover and landuse in Awka Capital Territory for the last 27 years (1990 – 2017); ascertain the trend of change and transition of the landcover/landuse classes during this period; validate Prescott spatial growth model using landcover/landuse reference data for 2018 and image correlation; and predict the future urban development dynamics for the next 30 years (2018 – 2048). The methodology involved acquisition of medium resolution Landsat and Sentinel Satellite images for 1990, 1999, 2008 and 2017, image pre-processing, development of classification scheme, landcover/landuse classification, trend analysis, landcover/landuse transition and impact analysis, Prescott Spatial Growth Model calibration, validation and future urban projection to 2048.The results revealed that urban area grew from 27.92% to 31.19%, to an of area of 14437.68 hectares between 1990 and 1999, 31.19% to 33.67%, to an area of 15586.73 hectares between 1999 and 2008, and 33.67% to 37.24%, to an area of 17237.45 hectares between 2008 and 2017. Trend of change analysis indicated that urban area had an annual rate of change of 0.62% between 1990 and 1999, 0.43% between 1999 and 2008 and 0.56% between 2008 and 2017. Transition results showed that between 1990 and 1999, urban area gained 1272.73 hectares from vegetation and 242.5 hectares from open space, also between 1999 and 2008 urban area gained 1000 hectares from vegetation and 149.05 hectares from open space, in the last epoch between 2008 and 2017 urban area gained 1068.27 hectares from vegetation, 582.45 hectares from open space. The study revealed two patterns inherent in the study area: edge-expansion and infilling, with edge-expansion being the most dominant growth pattern in the study area between 1990 and 2017, there was no evidence of spontaneous pattern of growth within the study area, while also revealing a consistent increase in high surface temperature in urban areas, a diminishing open space and a growing trend of deforestation in the study area. Hypothesis testing also validated the claim that vegetation and open space lost part of their area mass to urban area. Validation of Prescott Spatial growth model gave an overall accuracy of 93.36%, kappa of 0.9083, model error of 6.64% and an image correlation of 0.9585. Prediction of the future urban development dynamics of Awka Capital Territory in 2048 revealed that urban areas is expected to increase from 35.45% to 49.41% i.e. from area coverage of 17798.44 hectares to 22871.51 hectares. It was recommended that the approach be used as tool for planning and decision making in urban development.