Urban Studies of Accra

Accra is one of the largest and most important cities in sub-Saharan Africa. The aim of this article is to assess the evolution of urban studies in Accra and its main historical and contemporary foci. Early knowledge on urban Accra is fragmentary and orientated toward European contact points and urban plans, ostensibly from the gaze of Europeans. Writings from Euro-Africans such as Carl Reindorf provide a different prism into the precolonial, indigenous, urban society, whereas most indigenous urban knowledge was situated in the oral tradition at this time. Around independence, officially appointed social anthropologists wrote about an indigenous community in Tema and surveyed the multiethnic Accra environment. From independence in 1957 until the early 1980s, social scientists viewed the urban settlement as an alien, Western intervention. Local scholarship on Accra was sidelined as the academy in a poor, emergent nation became preoccupied with the genesis of nation-state building and the establishment of viable academic departments in national universities, and growing proportions of migrants regarded “home” as somewhere else, that is, ancestral villages. In the 1970s Accra was inserted into world history and social history, and social scientists began to study residential geographies, but scholarship at the city-scale remained sparse. Engagement with world and social histories and the social sciences demonstrated that history matters, but not in linear and teleological ways. The liberalization era ushered in by structural adjustment policies (SAPs) in 1983 invigorated studies of Accra’s urban impacts and effects. Much of this research was disseminated by international scholars, as Ghanaian scholars had to contend with the negative impacts of SAPs on their own universities and households. Since the turn of the 21st century, scholarship on Accra, and African cities in general, has been increasing. Diverse research questions and a multiplicity of methodologies and frameworks seek to engage Western urban theories and other variants, undertake policy-relevant work, assess ethnic and residential dynamics, contribute to international urban debates, and advance postcolonial and revisionist accounts of urbanism. Viewed at the third decade of the 21st century, scholarship on Accra is of diverse origins, encompassing scholarship from locals, members of the diaspora, and international urbanists, and a promising tilt is local–international collaborations co-producing knowledge.

Achieving sustainable development goals from the perspective of solid waste management plans

Achieving the Sustainable Development Goals (SDGs) by 2030 ad is one of the challenges and among the cross-cutting issues that countries around the world strive to achieve, despite it is not mandatory, to take control of the various negative environmental, economic, social, and urban impacts that threatened cities, in addition to benefits that are realized from achieving it. The research aims to promote the achievement of Sustainable Development Goals from the perspective of solid waste management (SWM) plans and programs, through analyzing and finding the interrelationship between SWM plans and programs and the related specific targets for each goal, in addition to using experts’ questionnaires to conclude the varying degrees of impact of SWM plans and programs at the level of 17 SDGs, which have been classified into groups, according to the most and the least affected by the SWM plans and programs. Where the goals of “sustainable cities and communities” and “good health and well-being” came in the lead of the goals; however, the goals of “quality education” and “peace, justice, and institutions” came in the tail of the goals that are affected by SWM plans and programs, according to the experts’ opinion.

Heavy rainfall event on 30th June 2017 in Moscow: physical drivers and statistical background

<p>The extreme rainfall on June 30, 2017 in the central part of the European territory of Russia is one of the strongest precipitation events ever observed in this region. According to ground observations, it caused the record precipitation amount per day for June in Moscow (65 mm) since 1970.</p><p>Our study considers physical and synoptic drivers of the extreme rainfall on June 30, 2017 as well as statistical estimates of such phenomena’s repeatability for the Moscow region. The degree of extremality of this phenomenon has been assessed using long-term observational time series since second half of the 20<sup>th</sup> century. Based on meteorological observations, radar data and ERA5 reanalysis we demonstrate that rainfall was associated with three mesoscale convective systems (two squall lines [Markowski, Richardson, 2010] and one meso-beta scale convective system) which appeared in the warm sector of a cyclone. The main cause for their development was an anomalously high total moisture content for the region which reached 41.5 kg / m<sup>2 </sup>and exceeded 0.995 percentile in the sounding data over Moscow [Durre et al., 2006] for the period 1957 – 2017. An analysis of the water vapor balance components using ERA5 reanalysis showed that advection of water vapor was the main factor in the appearance of the quasilinear region of an extremely high moisture content (“atmospheric river”). A smaller but very noticeable role was played by evaporation from the earth surface, largely controlled by the soil moisture.</p><p>Besides evaporation, another local factor which may intensify precipitation are the physical effects induced by a big city [Han et al., 2014]. To test the role of the Moscow city and soil moisture in the June 30 case the mesoscale non-hydrostatic model COSMO 5.05 with 3 km grid was used. The simulation result confirmed an idea of the significant role of evaporation from the earth's surface in precipitation intensity: a 10-times decrease in soil moisture in the initial conditions led to a 3-times decrease in the daily amount of precipitation in the study area. Urban-induced effects of the Moscow megacity were studied by running sensitivity model experiments with COSMO where bulk urban canopy model TERRA_URB was switched on or off. The account for urban surface effects did not provide any noticeable increase in the amount of precipitation in the Moscow region, but led to redistribution of the daily precipitation sum and its increase at the leeward side of the megacity.</p><p><strong>Acknowledgements:</strong></p><p>The bulk of the study was funded by Russian Foundation for Basic Research under project number 20-35-70044. The statistical assessment was supported by the grant of President of Russian Federation for young PhD scientists No. МК-5988.2021.1.5.</p><p><strong>References:</strong></p><p>Durre, I., Vose, R. S., & Wuertz, D. B. (2006). Overview of the integrated global radiosonde archive. <em>Journal of Climate</em>, <em>19 </em>(1), 53-68.</p><p>Han, J. Y., Baik, J. J., & Lee, H. (2014). Urban impacts on precipitation. <em>Asia-Pacific Journal of Atmospheric Sciences</em>, <em>50 </em>(1), 17-30.</p><p>Markowski, P., & Richardson, Y. (2011). <em>Mesoscale meteorology in midlatitudes</em> (Vol. 2). John Wiley & Sons.</p>

Urban Impacts of Mobile Fuel Delivery Service

Mobile fuel delivery (MFD) uses a fueling truck to fill up personal and commercial fleet vehicles while they are parked overnight. This study used a sample data set provided by a San Francisco Bay Area company to explore the potential impacts on vehicle miles traveled (VMT), carbon dioxide (CO2) emissions, and traffic congestion. An analysis of vehicle travel associated with gas station trips was conducted to establish a basis for comparison. Future scenarios comparing the potential impacts of scaled-up MFD services in 2030 were also developed. The study concluded that MFD services compared favorably to gas stations in relation to environmental and traffic benefits in the longer term, even though personal fueling trips tended to generate low VMT. Benefits stemmed from efficiencies achieved by fueling multiple vehicles per delivery trip, replacing car share vehicle fueling trips, and removing trips from the network during peak hours. This analysis estimated that total annual CO2 emissions associated with fuel delivery operations in the Bay Area were 76 metric tons, which is less than a typical gas station with 97 metric tons. Under assumptions of declining demand for gasoline and significantly fewer gas stations, and with highly efficient optimized operations, mobile delivery could gain up to 5% market share for gas and not add additional VMT over the business as usual scenario.

Urban requalification and economic sustainability: the case of the Genoa levante waterfront [Riqualificazione urbana e sostenibilità economica: il caso del waterfront di levante di Genova]

After the season of major projects and major urban maintenance, completed with the event of Genoa, European Capital of Culture of the now distant 2004, the urban redevelopment project of the Genoese urban waterfront in the Levante sector (ie the area that physically connects the Expo area with the Fiera del Mare complex) is the largest project involving the Genoese urban structure of the last few years. The complex vicissitudes linked to a highly complex design process (on the area in question overlook very different functions ranging from the naval industry to the yachting port, up to the fair pavilions), create a scenario in which differentiated interests arise and where the balance between costs and benefits is important to the success of the operation. The Municipality of Genoa has started the process for the redevelopment of the area through a design competition for the selection of the best proposal to be made to an interested party to be selected in a subsequent public selection. The urban impacts on the infrastructural system, on the allocation of new public spaces, on the location of new “valuable” functions, as well as the overall urban redevelopment effect will affect a large area in which the patrimonial benefits deriving from the post project operation will undoubtedly be relevant. The amount of public finances in the operation and the complexity of the design choices that must be made require careful assessment not only of the quality of the proposal but also of its economic and financial sustainability. Considering the high costs of demolition of existing buildings and structures, it must guarantee adequate margins of profitability for the investor, otherwise the operation will be unsuccessful. The economic evaluation therefore assumes a strategic role in identifying the best design solution. This contribution deals with the case study of the urban redevelopment project of the area of the former Genoa Fair started by the Municipality of Genoa in 2016 through a design competition called “BluePrint”. In addition to the analysis of the urban aspects, a verification of the economic feasibility of the intervention has been developed, starting from the checks presented by the participants in the competition. The objective is to determine - for some significant variables (cost of the areas) - what are the conditions of sustainability for the operator who will carry out the intervention

Measuring and Monitoring Urban Impacts on Climate Change from Space

As urban areas continue to expand and play a critical role as both contributors to climate change and hotspots of vulnerability to its effects, cities have become battlegrounds for climate change adaptation and mitigation. Large amounts of earth observations from space have been collected over the last five decades and while most of the measurements have not been designed specifically for monitoring urban areas, an increasing number of these observations is being used for understanding the growth rates of cities and their environmental impacts. Here we reviewed the existing tools available from satellite remote sensing to study urban contribution to climate change, which could be used for monitoring the progress of climate change mitigation strategies at the city level. We described earth observations that are suitable for measuring and monitoring urban population, extent, and structure; urban emissions of greenhouse gases and other air pollutants; urban energy consumption; and extent, intensity, and effects on surrounding regions, including nearby water bodies, of urban heat islands. We compared the observations available and obtainable from space with the measurements desirable for monitoring. Despite considerable progress in monitoring urban extent, structure, heat island intensity, and air pollution from space, many limitations and uncertainties still need to be resolved. We emphasize that some important variables, such as population density and urban energy consumption, cannot be suitably measured from space with available observations.

Benthic Diatom Communities in Urban Streams and the Role of Riparian Buffers

Urbanization impacts stream ecosystems globally through degraded water quality, altered hydrology, and landscape disturbances at the catchment and riparian scales, causing biodiversity losses and altered system functioning. Addressing the “urban stream syndrome” requires multiple mitigation tools, and rehabilitation of riparian vegetation may help improve stream ecological status and provide key ecosystem services. However, the extent to which forested riparian buffers can help support stream biodiversity in the face of numerous environmental contingencies remains uncertain. We assessed how a key indicator of stream ecological status, benthic diatoms, respond to riparian habitat conditions using 10 urban site pairs (each comprising of one unbuffered and one buffered reach), and additional urban downstream and forest reference upstream sites in the Oslo Fjord basin. Diatom communities were structured by multiple drivers including spatial location, land use, water quality, and instream habitat. Among these, riparian habitat condition independently explained 16% of variation in community composition among site pairs. Changes in community structure and indicator taxa, along with a reduction in pollution-tolerant diatoms, suggested tangible benefits of forested riparian buffers for stream biodiversity in urban environments. Managing urban impacts requires multiple solutions, with forested riparian zones providing a potential tool to help improve biodiversity and ecosystem services.

Seasonal records of benthic macroinvertebrates in a stream on the eastern edge of the Iguaçu National Park, Brazil

Background Iguaçu National Park (INP) is known worldwide due to Iguaçu Waterfalls, being considered a World Natural Heritage by UNESCO. The INP is one of the last large forested extensions of inland Brazil that provides protection to the Atlantic Forest, one of the world’s biodiversity hotspots. However, its Natural Heritage status has been threatened by the construction and operation of the Baixo Iguaçu dam, agricultural and urban impacts on its boundaries and the increasing interest of the Brazilian government in re-opening of the “Colono road”, an old illegal road that crossed the interior of the park. Indeed, since benthic macroinvertebrates have been widely used for the environmental assessment of streams, records and abundance of their taxa under different seasonal periods may provide an additional dataset for biomonitoring of hydrographic systems in the face of current anthropogenic impacts on the INP boundaries and other similar streams on forest edges. New information In this study, we improved the sampling design of benthic macroinvertebrates and provided seasonal records covering distinct precipitation/temperature periods between 2016 and 2017 of a stream on the eastern edge of the Iguaçu National Park, Brazil. The records total 2,840 individuals distributed in 88 different taxa. The most abundant taxa were the Diptera subfamilies, Chironominae (n = 1,487) and Tanypodinae (n = 256), besides the Heterelmis genus (n = 152, Elmidae; Coleoptera). Diptera was the richest order in number of families (n = 8), while Leptophlebiidae (Ephemeroptera) was the richest taxonomic family in number of genera (n = 11). Aegla (Crustacea) and the Insecta genera, Heterelmis, Hexacylloepus, Noelmis, Phylloicus and Thraulodes, were recorded through all samplings. Twenty-five genera of Ephemeroptera, Plecoptera, Trichoptera (EPT) and Odonata were recorded during intermediate precipitation/temperature periods. Twenty-one of them were recorded in May 2016, with five genera standing out in abundance (Hydrosmilodon, Anacroneuria, Argia, Coryphaeschna, Americabaetis) and four (Needhamella, Tikuna, Simothraulopsis, Neocordulia) in December 2016. Four general taxa were exclusive of the lower precipitation/temperature period (August 2016), standing out in abundance were the Oxystigma (Odonata) and Corydalus (Megaloptera) genera. In March 2017 (higher precipitation/temperature period), four exclusive taxa were recorded, amongst them, the Chimarra (Trichoptera) genus. Furthermore, seasonal records demonstrated higher occurrences and abundance of macroinvertebrates during the intermediate and lower precipitation/temperature periods, besides a varied taxa composition throughout the year, with the presence of both sensitive and tolerant groups to environmental impacts. Our findings suggest that the number and composition of the local-stream macrobenthic fauna were influenced by the seasonal climatic regime. These changes should be considered in the limnological monitoring developed on the hydrographic systems of INP eastern edges to improve the assessment of environmental quality under different local seasonal conditions.