Coastal wetlands are complex ecosystems that support biodiversity. They provide many benefits, including flood mitigation and sustenance for communities. The unique characteristics of wetlands make them vulnerable to natural and human-induced disturbances. Numerous factors, including industrialisation, urbanisation, and climate change, add to this phenomenon. The activities that threaten coastal wetlands in the world are relevant to coastal wetlands in Ghana. The Songor and Sakumo wetland catchments are international ecosystems endangered by land modifications and sea level rise. There are gaps in the body of knowledge that need investigation as regards underlying processes and transformation. This study assessed land use and land cover (LULC) changes between 1990 and 2020. The study used geospatial techniques and intensity analysis. LULC change results were from Landsat images (1990, 2000, 2011, and 2020). These changes were attributed to an increase in human activities. Changes in the Sakumo wetland catchment fell more into human-induced LULC categories, and vice versa for the Songor wetland catchment. The study recommends comprehensive methods of LULC change analysis. This would enhance biodiversity and allow the sustainable usage of wetland resources.
Flooding is the most pervasive hydrological disaster globally. This study presents a comprehensive analysis of torrential rain and flood characteristics across three major urban agglomerations (CY, MRYR, and YRD) in the Yangtze River Basin from 1991 to 2020. Utilizing satellite-derived microwave SSM/I data and CHIRPS precipitation datasets, this study examines the impacts of urbanization and climate change on flood risk patterns. The results showed: (1) In 1998, the MRYR had the highest flood risk due to heavy rainfall and poor flood control, but by 2020, risk shifted to the CY with rapid urbanization and more rainfall, while the YRD maintained the lowest risk due to advanced flood control. (2) The relationship between impervious surface area and flood risk varied by region. The CY showed a negative correlation (−0.41), suggesting effective flood mitigation through topography and infrastructure; the MRYR had a slight positive correlation (0.12), indicating increased risks from urban expansion; and the YRD’s weak negative correlation (−0.18) reflected strong flood control systems. This research underscores the imperative of strategic urban planning and effective water resource management to mitigate future flood risks and contributes valuable insights to ongoing efforts in flood disaster prevention and control within the Yangtze River Basin.
9 May 2023 in Çanakkale Onsekiz Mart University Journal of Marine Sciences and Fisheries
Stock assessment indicators of Pagrus caeruloestictus, Pagellus bellotti, Dentex angolensis and Dentex congoensis from Ghana’s coastal waters were estimated between July 2018 and June 2019. Total length measurements of 2489 samples were collected from some selected coastal communities along the Greater Accra region of Ghana and analyzed using FISAT II Tool. The asymptotic length (L∞) for P. caeruleostictus, P. bellottii, D. angolensis and D. congoensis was 39.9 cm, 31.5 cm, 31.5 cm and 28.4 cm, respectively. The growth rate (K) was 0.18 yr-1 for P. caeruleostictus, 0.36 yr-1 for P. bellottii, 0.75 yr-1 for D. angolensis and 0.83 yr-1 for D. congoensis. The current exploitation rate (E) for P. caeruloestictus, P. bellotti, D. angolensis and D. congoensis was above the optimum level of 0.5, indicating that these species are facing high fishing pressure. To ensure sustainable management of the overexploited fish species, the need for relevant management measures such extension of the closed fishing season, reduced fishing effort and others are urgently required.