The urban environment has continued to experience changes from increasing impervious surfaces, which alters the proper functioning of the ecological zones and impairs water quality in the watershed. Impervious cover i...The urban environment has continued to experience changes from increasing impervious surfaces, which alters the proper functioning of the ecological zones and impairs water quality in the watershed. Impervious cover is predominantly used as an indicator to assist in understanding and forecasting the impact of human actions and other related activities on aquatic resources. In this study, the rate of change in land uses using the impervious surface as an indicator, and the percentage of imperviousness on the effect on water quality in the urban watershed were assessed. Ile-Ife was delineated as an urban watershed, and the percentage of imperviousness from 2008 to 2016 and the effect of imperviousness on water bodies were assessed. The study utilized ASTERDEM, Worldview (0.46 m), IKONOS (1.4 m), Landsat (30 m) for 2008 and 2016, GPS and Drone (10 cm). Water sampling was carried out in selected locations as generated by the impervious surface analyst tool, (ISAT). The percentage (%) of impervious surfaces accounted for 59.4% (4567.1/7691.5ha) in 2008 and 70.3% (5408.2/7691.5ha) in 2016, from the total number of lands investigated. The turbidity values from low to high regions were 32.3, 55.9 and 82.4 NUT. Changes in LULC of the watershed led to increased surface temperature, impermeable surfaces, and decreased vegetation, which exposes the area to flooding and reduced water quality. This study emphasized the importance of GIS and its integration into urban changes and water quality assessment.展开更多
Water is the essential resource of the 21st century where innovative water management strategies are needed to improve water security.This paper examines three case studies that exemplify the global water crisis,situa...Water is the essential resource of the 21st century where innovative water management strategies are needed to improve water security.This paper examines three case studies that exemplify the global water crisis,situated in rapidly urbanizing watersheds:Nairobi River Basin,Kenya;Citarum River Basin,Indonesia;and Addis Ababa River Basin,Ethiopia.Each of these watersheds are implementing large-scale water management strategies inclusive of local communities and regional governments to address water quality and waste management issues.The hydrosocial cycle(Linton,2010)provides a framework to investigate the social,technical and physical aspects of water flows.Using the hydrosocial cycle as an organizing framework,these watersheds are examined to highlight how water security underpins water justice.The issues of gender and inequity are often overlooked in larger policy,development,and infrastructure discussions where technical requirements,restoration management,and engineering solutions obscure power inequities.Projects are compared to assess the implementation of the hydrosocial cycle through a discussion of social power and structure,technology and infrastructure,and the materiality of water in each location.This comparison reveals a dependence on large-scale technical projects with limited community engagement,and a need for science-based river restoration management.Recommendations are provided to improve and address holistic water management.展开更多
文摘The urban environment has continued to experience changes from increasing impervious surfaces, which alters the proper functioning of the ecological zones and impairs water quality in the watershed. Impervious cover is predominantly used as an indicator to assist in understanding and forecasting the impact of human actions and other related activities on aquatic resources. In this study, the rate of change in land uses using the impervious surface as an indicator, and the percentage of imperviousness on the effect on water quality in the urban watershed were assessed. Ile-Ife was delineated as an urban watershed, and the percentage of imperviousness from 2008 to 2016 and the effect of imperviousness on water bodies were assessed. The study utilized ASTERDEM, Worldview (0.46 m), IKONOS (1.4 m), Landsat (30 m) for 2008 and 2016, GPS and Drone (10 cm). Water sampling was carried out in selected locations as generated by the impervious surface analyst tool, (ISAT). The percentage (%) of impervious surfaces accounted for 59.4% (4567.1/7691.5ha) in 2008 and 70.3% (5408.2/7691.5ha) in 2016, from the total number of lands investigated. The turbidity values from low to high regions were 32.3, 55.9 and 82.4 NUT. Changes in LULC of the watershed led to increased surface temperature, impermeable surfaces, and decreased vegetation, which exposes the area to flooding and reduced water quality. This study emphasized the importance of GIS and its integration into urban changes and water quality assessment.
基金This research was made possible by the US Global Water Partnership.
文摘Water is the essential resource of the 21st century where innovative water management strategies are needed to improve water security.This paper examines three case studies that exemplify the global water crisis,situated in rapidly urbanizing watersheds:Nairobi River Basin,Kenya;Citarum River Basin,Indonesia;and Addis Ababa River Basin,Ethiopia.Each of these watersheds are implementing large-scale water management strategies inclusive of local communities and regional governments to address water quality and waste management issues.The hydrosocial cycle(Linton,2010)provides a framework to investigate the social,technical and physical aspects of water flows.Using the hydrosocial cycle as an organizing framework,these watersheds are examined to highlight how water security underpins water justice.The issues of gender and inequity are often overlooked in larger policy,development,and infrastructure discussions where technical requirements,restoration management,and engineering solutions obscure power inequities.Projects are compared to assess the implementation of the hydrosocial cycle through a discussion of social power and structure,technology and infrastructure,and the materiality of water in each location.This comparison reveals a dependence on large-scale technical projects with limited community engagement,and a need for science-based river restoration management.Recommendations are provided to improve and address holistic water management.
