Hydro morphodynamic assessment of urban growth on the Muni lagoon catchment

Abstract

This study sought to conduct hydro-morphodynamic analysis occurring in the Muni Pomadze Lagoon. Laboratory analysis was employed to determine heavy metals (Cadmium, Lead, Iron, Manganese, and Zinc) present in water and fish samples within the Muni Lagoon. Remotely sensed images were used in modelling encroachment within the Muni catchment for the period 1990- 2019. Temperature and rainfall data were acquired from the Ghana Meteorological Agency to investigate climatic variations and its attendant effects on the catchment. Purposive sampling technique was employed to select ten (10) respondents to participate in interviews for multi-stakeholder cooperation and encroachment issues. Content analysis was used to support evidence gathered from the field. The study revealed that the Muni Lagoon and its tributaries are polluted with heavy metals (Cd, Pb, Fe, and Mn) comparing their concentrations with the USEPA and WRC limit. Fishes within the lagoon were found to pose no harm to consumers as traces of heavy metal were below the FAO/WHO maximum permissible limit. It was again revealed that there is a high rate of encroachment occurring within the catchment accompanied by variations in temperature and rainfall. There is lack of coordination between stakeholders responsible for conserving the Muni Lagoon catchment making the implementation of regulatory activities difficult. The study concluded that urban growth has increased anthropogenic pressures within the catchment that are negatively affecting functioning of the lagoon and its ecological resources. The study recommended that stakeholders should collaborate to regulate human activities within the catchment