scholarly journals The Impact of Rapid Urbanization and Public Housing Development on Urban Form and Density in Addis Ababa, Ethiopia

Land ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 66 ◽  
Author(s):  
Larsen ◽  
Yeshitela ◽  
Mulatu ◽  
Seifu ◽  
Desta

Urban development is occurring in many Sub-Saharan Africa cities and rapid urbanization is underway in the East African city of Addis Ababa, Ethiopia. In an effort to address urban poverty and increase homeownership opportunities for low and middle-income residents, the City Administration of Addis Ababa initiated a large-scale housing development project in 2005. The project has resulted in the completion of 175,000 units within the city with 132,000 more under construction. To understand the impacts of both rapid growth and the housing program’s impact on the city’s urban form, we compared the type and distribution of land uses in Addis Ababa, Ethiopia, between 2006 with 2016 using hand-digitized, ortho-rectified satellite images in Geographic Information Systems (GISs). While residential density has increased, overall density has decreased from 109 people/ha to 98 people/ha. We found that between 2006 and 2016, land occupied by residential housing increased from 33% to 39% and the proportion of informal housing decreased from 57% to 38%. Reflecting the country’s economic prosperity, there was a dramatic increase in the presence of single family housing, particularly on the city’s western side. In 2006, only 1% of residential areas were occupied by high-rise condominiums (4 floors or greater) and this increased to 11% by 2016. The majority of the new, higher density residential developments are located near the eastern edges of the city and this outlying location has significant implications for residents, infrastructure construction, and future development.

2021 ◽  
Vol 13 (2) ◽  
pp. 323
Author(s):  
Liang Chen ◽  
Xuelei Wang ◽  
Xiaobin Cai ◽  
Chao Yang ◽  
Xiaorong Lu

Rapid urbanization greatly alters land surface vegetation cover and heat distribution, leading to the development of the urban heat island (UHI) effect and seriously affecting the healthy development of cities and the comfort of living. As an indicator of urban health and livability, monitoring the distribution of land surface temperature (LST) and discovering its main impacting factors are receiving increasing attention in the effort to develop cities more sustainably. In this study, we analyzed the spatial distribution patterns of LST of the city of Wuhan, China, from 2013 to 2019. We detected hot and cold poles in four seasons through clustering and outlier analysis (based on Anselin local Moran’s I) of LST. Furthermore, we introduced the geographical detector model to quantify the impact of six physical and socio-economic factors, including the digital elevation model (DEM), index-based built-up index (IBI), modified normalized difference water index (MNDWI), normalized difference vegetation index (NDVI), population, and Gross Domestic Product (GDP) on the LST distribution of Wuhan. Finally, to identify the influence of land cover on temperature, the LST of croplands, woodlands, grasslands, and built-up areas was analyzed. The results showed that low temperatures are mainly distributed over water and woodland areas, followed by grasslands; high temperatures are mainly concentrated over built-up areas. The maximum temperature difference between land covers occurs in spring and summer, while this difference can be ignored in winter. MNDWI, IBI, and NDVI are the key driving factors of the thermal values change in Wuhan, especially of their interaction. We found that the temperature of water area and urban green space (woodlands and grasslands) tends to be 5.4 °C and 2.6 °C lower than that of built-up areas. Our research results can contribute to the urban planning and urban greening of Wuhan and promote the healthy and sustainable development of the city.


Author(s):  
Longbiao Chen ◽  
Chenhui Lu ◽  
Fangxu Yuan ◽  
Zhihan Jiang ◽  
Leye Wang ◽  
...  

Urban villages refer to the residential areas lagging behind the rapid urbanization process in many developing countries. These areas are usually with overcrowded buildings, high population density, and low living standards, bringing potential risks of public safety and hindering the urban development. Therefore, it is crucial for urban authorities to identify the boundaries of urban villages and estimate their resident and floating populations so as to better renovate and manage these areas. Traditional approaches, such as field surveys and demographic census, are time consuming and labor intensive, lacking a comprehensive understanding of urban villages. Against this background, we propose a two-phase framework for urban village boundary identification and population estimation. Specifically, based on heterogeneous open government data, the proposed framework can not only accurately identify the boundaries of urban villages from large-scale satellite imagery by fusing road networks guided patches with bike-sharing drop-off patterns, but also accurately estimate the resident and floating populations of urban villages with a proposed multi-view neural network model. We evaluate our method leveraging real-world datasets collected from Xiamen Island. Results show that our framework can accurately identify the urban village boundaries with an IoU of 0.827, and estimate the resident population and floating population with R2 of 0.92 and 0.94 respectively, outperforming the baseline methods. We also deploy our system on the Xiamen Open Government Data Platform to provide services to both urban authorities and citizens.


2008 ◽  
Vol 33 (1) ◽  
pp. 72-85
Author(s):  
Fereshteh Habib ◽  
Ibrahim Numan ◽  
Hifsiye Pulhan

In casting a new look at city; this study interprets the urban form in respect of the role played by human perception of space. The main aim of this research at a macro level is to attain a strong theorical basis through a multi-dimensional approach to the city. The method of analyzing and carrying out a critique of it at an applied level will clarify the impact, which cultural factors have in the formation of urban form. This preliminary recognition and idealism is based on a hermeneutic and deductive method that is particular to the intellectual sciences In the process of devising theories, studying the urban planning texts related to the subject of study and the conclusion from the field study which is carried out in the Isfahan Naghshe Jahan square in the Safavy period played a key role in the research in addition to the goals and questions.


2020 ◽  
Vol 24 (1) ◽  
pp. 13-44
Author(s):  
Diana Mihnea

During the 1920s, the city of Sibiu expanded by approximately 250 hectares, with an area that was three times larger than its historical core. This great expansion was the result of the application of the agrarian reform, whose laws allowed and encouraged the creation of new building plots in the cities of Transylvania, Banat, Crișana and Maramureș. Although this was the largest territorial growth of the city up until that time, it was not controlled by the municipality and its Technical Office. In fact, the city authorities were excluded from most stages of the decision-making process. All the decisions were taken by the central and local institutions of the Ministry of Agriculture and Domains that were in charge with the application of the agrarian reform. The territorial expansion was not based on any large-scale studies regarding the needs of the city or the impact on its future development. In fact, the proportions and the directions of the city’s expansion were dictated mostly by the number of accepted requests for building plots and by the position of the areas that could be expropriated and that were suitable to be parcelled. The creation of the large new allotments was simultaneous with the efforts of the municipality to draft a systematisation plan that was now urgently necessary, given the rapidly changing situation of the city, and it was imposed by the new administrative legislation of Romania. So, shortly after the parceling plans were issued and the new building plots were distributed to those entitled, a preliminary systematization plan – drafted between 1926 and 1928 – proposed the revision of the new allotments and the modification of the procedure for assigning the building plots according to a system that would allow a gradual territorial growth of the city. Hence, during the second half of the 1920s and the beginning of the 1930s there were ample negotiations over the new urban territory, involving not only the Ministry of Agriculture and Domains, but also the Ministry of Interior and the Superior Technical Council. In the end, after almost a decade of negotiations, only minor adjustments were made to the allotments and the provisions of the systematisation plan were only partly applied.


2019 ◽  
Vol 11 (14) ◽  
pp. 3854
Author(s):  
Luis Alfonso Escudero Gómez

Historic centers have become first-line tourist destinations. In order to achieve sustainable development, it is essential to get to know the opinions of the host community on the impact of tourism, the positives, as well as the negatives. This paper aims to understand the residents’ opinions and perceptions of destinations as the historic cities. This research looks into the residents’ opinions on the impact of tourism in the historic city of Toledo, Spain. The results of a quantitative survey among 442 residents in the city of Toledo are presented. The study is a revision of the literature and analysis and explanation of an empiric study’s results. Descriptive statistics have been used, as well as factor analysis and non-parametric tests to analyze data. The main results point out that residents have a positive vision of tourism development, rather than negative. The economic importance of tourism and its ability to create jobs stand out. However, they also think that the historic center is being turned into a museum for tourists. Analyzing their opinions according to certain demographic and socioeconomic characteristics, some major differences come up, such as that the inhabitants of residential areas have a more positive opinion than those who live in the historic center. Understanding the perspective of the residents can help the managers and planners of the tourism in the city to play down the potential negative impact of tourism and to achieve support from the host community in regards to tourism.


2011 ◽  
Vol 4 (1) ◽  
pp. 193-211 ◽  
Author(s):  
Xin Gu

This paper deals with the development of ’art clusters’ and their relocation in the city of Shanghai. It first looks at the revival of the city’s old inner city industrial area (along banks of Suzhou River) through ’organic’ or ’alternative’ artist-led cultural production; second, it describes the impact on these activities of the industrial restructuring of the wider city, reliant on large-scale real estate development, business services and global finance; and finally, outlines the relocation of these arts (and related) cultural industries to dispersed CBD locations as a result of those spatial, industrial and policy changes.


2020 ◽  
pp. 901-933
Author(s):  
Sarah Fidler ◽  
Timothy E.A. Peto ◽  
Philip Goulder ◽  
Christopher P. Conlon

Since its discovery in 1983, the human immunodeficiency virus (HIV) has been associated with a global pandemic that has affected more than 78 million people and caused more than 39 million deaths. Globally, 36.9 million (34.3–41.4 million) people were living with HIV at the end of 2013. An estimated 0.8% of adults aged 15–49 years worldwide are living with HIV, although the burden of the epidemic continues to vary considerably between countries and regions. Sub-Saharan Africa remains most severely affected, with nearly 1 in every 20 adults living with HIV and accounting for nearly 71% of the people living with HIV worldwide. The impact of HIV in some African countries has been sufficient to reverse population growth and reduce life expectancy into the mid-30s, although HIV incidence has declined in some of these high-prevalence countries. However, there are large-scale HIV epidemics elsewhere (e.g. India, the Russian Federation, and Eastern Europe).


Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 810 ◽  
Author(s):  
Antonio Barragán-Escandón ◽  
Esteban Zalamea-León ◽  
Julio Terrados-Cepeda

Previous research has assessed the potential of solar energy against possible demand; however, the sustainability issues associated with the use of large-scale photovoltaic deployment in urban areas have not been jointly established. In this paper, the impact of photovoltaic energy in the total urban energy mix is estimated using a series of indicators that consider the economic, environmental and social dimensions. These indicators have been previously applied at the country level; the main contribution of this research is applying them at the urban level to the city of Cuenca, Ecuador. Cuenca is close to the equatorial line and at a high altitude, enabling this area to reach the maximum self-supply index because of the high irradiation levels and reduced demand. The solar potential was estimated using a simple methodology that applies several indexes that were proven reliable in a local context considering this particular sun path. The results demonstrate that the solar potential can meet the electric power demand of this city, and only the indicator related to employment is positive and substantially affected. The indicators related to the price of energy, emissions and fossil fuel dependency do not change significantly, unless a fuel-to-electricity transport system conversions take place.


Author(s):  
Martin Fleischmann ◽  
Ombretta Romice ◽  
Sergio Porta

Unprecedented urbanisation processes characterise the Great Acceleration, urging urban researchers to make sense of data analysis in support of evidence-based and large-scale decision-making. Urban morphologists are no exception since the impact of urban form on fundamental natural and social patterns (equity, prosperity and resource consumption’s efficiency) is now fully acknowledged. However, urban morphology is still far from offering a comprehensive and reliable framework for quantitative analysis. Despite remarkable progress since its emergence in the late 1950s, the discipline still exhibits significant terminological inconsistencies with regards to the definition of the fundamental components of urban form, which prevents the establishment of objective models for measuring it. In this article, we present a study of existing methods for measuring urban form, with a focus on terminological inconsistencies, and propose a systematic and comprehensive framework to classify urban form characters, where ‘urban form character’ stands for a characteristic (or feature) of one kind of urban form that distinguishes it from another kind. In particular, we introduce the Index of Elements that allows for a univocal and non-interpretive description of urban form characters. Based on such Index of Elements, we develop a systematic classification of urban form according to six categories (dimension, shape, spatial distribution, intensity, connectivity and diversity) and three conceptual scales (small, medium, large) based on two definitions of scale (extent and grain). This framework is then applied to identify and organise the urban form characters adopted in available literature to date. The resulting classification of urban form characters reveals clear gaps in existing research, in particular, in relation to the spatial distribution and diversity characters. The proposed framework reduces the current inconsistencies of urban morphology research, paving the way to enhanced methods of urban form systematic and quantitative analysis at a global scale.


2018 ◽  
Vol 40 ◽  
pp. 05010
Author(s):  
Brian Perry ◽  
Colin Rennie ◽  
Andrew Cornett ◽  
Paul Knox

Due to excessive rainfall in June of 2013, several rivers located in and near the City of Calgary, Canada experienced significant flooding events. These events caused severe damage to infrastructure throughout the city, precipitating a renewed interest in flood control and mitigation strategies for the area. A major potential strategy involves partial diversion of Elbow River flood water to the proposed Springbank Off-Stream Storage Reservoir. A large scale physical model study was conducted to optimize and validate the design of a portion of the new project. The goals of the physical model were to investigate diversion system behaviors such as flow rates, water levels, sediment transport and, debris accumulation, and optimize the design of new flow control structures to be constructed on the Elbow River. In order to accurately represent the behavior of debris within the system due to flooding, large woody debris created from natural sources was utilized in the physical model and its performance was compared to that of debris of the same size fabricated from pressed cylindrical wood dowels. In addition to comparing the performance of these two debris types, the impact of root wads on debris damming was also investigated. Significant differences in damming behavior was shown to exist between the natural debris and the fabricated debris, while the impact of root wad on damming affected the dam structure and formation. The results of this experiment indicate that natural debris is preferred for studies involving debris accumulation.


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