Landuse, landcover change dynamics and flooding in the lower Niger basin Onitsha, South Eastern Nigeria

• Nkiruka, Ezebube M. ^[1] ; Chinedu, Ani D. ^[1] ; Smart, Uchegbu N. ^[1]
  1. [1] Centre for Environmental Management and Control, University of Nigeria Enugu Campus, Nigeria
• Localización: Land use policy: The International Journal Covering All Aspects of Land Use, ISSN 0264-8377, ISSN-e 1873-5754, Nº. 131, 2023
• Idioma: inglés
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• Resumen

  • This study looked at the factors contributing to Onitsha's incessant flooding, specifically landuse and land cover depletion. The landuse/landcover changes during a period of ten years (2008 – 2018) and the relevant variables were studied in the lower Niger Basin, focusing on Onitsha, Anambra State. Three sets of Enhanced Thematic Mapper Plus (ETM+) Landsat imagery maps from 2008, 2013, and 2018 were used to construct three Geographic Information Systems (GIS) based landuse/landcover maps of the research location and cross-tabulation method was adopted for the Change Detection analysis. The results demonstrated that between 2008 and 2013, built-up areas expanded by 9.4%, and between 2013 and 2018, they increased by 9.4%. Then it grew by 5.5%, resulting in a total area of 470 ha and 275 ha. Then, between 2008 and 2018, built-up added 745 ha in the study region, whereas vegetation lost 638 ha between 2008 and 2013, and another 97 ha between 2013 and 2018, for a total loss of 735 ha. Between 2008 and 2013, the area of bare ground increased by 1.3%, to 65 ha, while between 2013 and 2018, the area of bare ground decreased by 0.3%, to 15 ha. This study also discovered a 40-hectare rise in waterbody between 2008 and 2013 and a 100-hectare loss between 2013 and 2018. Based on the findings, the changes in landuse/landcover change detection provided insight into non-compliance with existing landuse acts and the implementation strategies of government agencies enforcing them.