Urban Growth and Land Use/Land Cover Changes in the Post-Genocide Period, Kigali, Rwanda

2021 ◽  
pp. 097542532199797
Author(s):  
Gilbert Nduwayezu ◽  
Vincent Manirakiza ◽  
Leon Mugabe ◽  
Josephine Mwongeli Malonza

Kigali is a rapidly growing city, as exemplified by the phenomenal increase of its inhabitants from 358,200 in 1996 to 1,630,657 in 2017. Nevertheless, there is a paucity of detailed analytical information about the processes and factors driving unprecedented urban growth in the period following the genocide perpetrated against the Tutsi (1994) and its impact on the natural environment. This article, therefore, analyses the growth of the city of Kigali with respect to its post-genocide spatial and demographic dimensions. The methodology involves a quantification of urban growth over the period of the last 30 years using remote-sensing imagery coupled with demographic data drawn from different sources. The analysis of land cover trends shows how significant the pressure of urban expansion has been on the natural environment, with a 14 per cent decrease in open land between 1999 and 2018. Spatially, the average annual growth rate was almost 10.24 per cent during the same period. This growth is associated with the building of a large number of institutions, schools and industries. Moreover, the increase in low-income residents led to the construction of bungalows expanding on large suburbs and the development of new sub-centres in the periphery instead of high-rise apartments.

Author(s):  
Андрій Юрійович Шелестов ◽  
Алла Миколаївна Лавренюк ◽  
Богдан Ялкапович Яйлимов ◽  
Ганна Олексіївна Яйлимова

Ukraine is an associate member of the European Union and in the coming years it is expected that all data and services already used by EU countries will be available to Ukraine. The lack of quality national products for assessing the development and planning of urban growth makes it impossible to assess the impact of cities on the environment and human health. The first steps to create such products for the cities of Ukraine were initiated within the European project "SMart URBan Solutions for air quality, disasters and city growth" (SMURBS), in which specialists from the Space Research Institute of NAS of Ukraine and SSA of Ukraine received the first city atlas for the Kyiv city, which was similar to the European one. However, the resulting product had significantly fewer types of land use than the European one and therefore the question of improving the developed technology arose. The main purpose of the work is to analyze the existing technology of European service Urban Atlas creation and its improvement by developing a unified algorithm for building an urban atlas using all available open geospatial and satellite data for the cities of Ukraine. The development of such technology is based on our own technology for classifying satellite time series with a spatial resolution of 10 meters to build a land cover map, as well as an algorithm for unifying open geospatial data to urban atlases Copernicus. The technology of construction of the city atlas developed in work, based on the intellectual model of classification of a land cover, can be extended to other cities of Ukraine. In the future, the creation of such a product on the basis of data for different years will allow to assess changes in land use and make a forecast for further urban expansion. The proposed information technology for constructing the city atlas will be useful for assessing the dynamics of urban growth and closely related social and economic indicators of their development. Based on it, it is also possible to assess indicators of achieving the goals of sustainable development, such as 11.3.1 "The ratio of land consumption and population growth." The study shows that the city atlas obtained for the Kyiv city has a high level of quality and has comparable land use classes with European products. It indicates that such a product can be used in government decision-making services.


2021 ◽  
Vol 10 (2) ◽  
pp. 101
Author(s):  
Francisco Maturana ◽  
Mauricio Morales ◽  
Fernando Peña-Cortés ◽  
Marco A. Peña ◽  
Carlos Vielma

Urbanization is spreading across the world and beyond metropolitan areas. Medium-sized cities have also undergone processes of accelerated urban expansion, especially in Latin America, thanks to scant regulation or a complete lack thereof. Thus, understanding urban growth in the past and simulating it in the future has become a tool to raise its visibility and challenge territorial planners. In this work, we use Markov chains, cellular automata, multi-criteria multi-objective evaluation, and the determination of land use/land cover (LULC) to model the urban growth of the city of Temuco, Chile, a paradigmatic case because it has experienced powerful growth, where real estate development pressures coexist with a high natural value and the presence of indigenous communities. The urban scenario is determined for the years 2033 and 2049 based on the spatial patterns between 1985 and 2017, where the model shows the trend of expansion toward the northeast and significant development in the western sector of the city, making them two potential centers of expansion and conflict in the future given the heavy pressure on lands that are indigenous property and have a high natural value, aspects that need to be incorporated into future territorial planning instruments.


2010 ◽  
Vol 1 (2) ◽  
pp. 55-70 ◽  
Author(s):  
Hyun Joong Kim

Rapidly growing urban areas tend to reveal distinctive spatial and temporal variations of land use/land cover in a locally urbanized environment. In this article, the author analyzes urban growth phenomena at a local scale by employing Geographic Information Systems, remotely sensed image data from 1984, 1994, and 2004, and landscape shape index. Since spatial patterns of land use/land cover changes in small urban areas are not fully examined by the current GIS-based modeling studies or simulation applications, the major objective of this research is to identify and examine the spatial and temporal dynamics of land use changes of urban growth at a local scale. Analytical results demonstrate that sizes, locations, and shapes of new developments are spatio-temporally associated with their landscape variations and major transportation arteries. The key findings from this study contribute to GIS-based urban growth modeling studies and urban planning practices for local communities.


2020 ◽  
Vol 12 (21) ◽  
pp. 3662
Author(s):  
Vineet Chaturvedi ◽  
Monika Kuffer ◽  
Divyani Kohli

A large part of the population in low-income countries (LICs) lives in fragile and conflict-affected states. Many cities in these states show high growth dynamics, but little is known about the relation of conflicts and urban growth. In Afghanistan, the Taliban regime, which lasted from 1996 to 2001, caused large scale displacement of the population. People from Afghanistan migrated to neighboring countries like Iran and Pakistan, and all developments came to a halt. After the US invasion in October 2001, all the major cities in Afghanistan experienced significant population growth, in particular, driven by the influx of internally displaced persons. Maximum pressure of this influx was felt by the capital city, Kabul. This rapid urbanization, combined with very limited capacity of local authorities to deal with this growth, led to unplanned urbanization and challenges for urban planning and management. This study analyses the patterns of growth between 2001 and 2017, and the factors influencing the growth in the city of Kabul with the help of high-resolution Earth Observation-based data (EO) and spatial logistic regression modelling. We analyze settlement patterns by extracting image features from high-resolution images (aerial photographs of 2017) and terrain features as input to a random forest classifier. The urban growth is analyzed using an available built-up map (extracted from IKONOS images for the year 2001). Results indicate that unplanned settlements have grown 4.5 times during this period, whereas planned settlements have grown only 1.25 times. The unplanned settlements expanded mostly towards the west and north west parts of the city, and the growth of planned settlements happened mainly in the central and eastern parts of the city. Population density and the locations of military bases are the most important factors that influence the growth, of both planned and unplanned settlements. The growth of unplanned settlement occurs predominantly in areas of steeper slopes on the hillside, while planned settlements are on gentle slopes and closer to the institutional areas (central and eastern parts of the city). We conclude that security and availability of infrastructure were the main drivers of growth for planned settlements, whereas unplanned growth, mainly on hillsides, was driven by the availability of land with poor infrastructure.


2019 ◽  
Vol 2 ◽  
pp. 1-8
Author(s):  
Mojtaba Eslahi ◽  
Rani El Meouche ◽  
Anne Ruas

<p><strong>Abstract.</strong> Many studies, using various modeling approaches and simulation tools have been made in the field of urban growth. A multitude of models, with common or specific features, has been developed to reconstruct the spatial occupation and changes in land use. However, today most of urban growth techniques just use the historical geographic data such as urban, road and excluded maps to simulate the prospective urban maps. In this paper, adding buildings and population data as urban fabric factors, we define different urban growth simulation scenarios. Each simulation corresponds to policies that are more or less restrictive of space considering what these territories can accommodate as a type of building and as a global population.</p><p>Among the urban growth modeling techniques, dynamic models, those based on Cellular Automata (CA) are the most common for their applications in urban areas. CA can be integrated with Geographical Information Systems (GIS) to have a high spatial resolution model with computational efficiency. The SLEUTH model is one of the cellular automata models, which match the dynamic simulation of urban expansion and could be adapted to morphological model of the urban configuration and fabric.</p><p>Using the SLEUTH model, this paper provides different simulations that correspond to different land priorities and constraints. We used common data (such as topographic, buildings and demography data) to improve the realism of each simulation and their adequacy with the real world. The findings allow having different images of the city of tomorrow to choose and reflect on urban policies.</p>


Author(s):  
Michael Ajide Oyinloye ◽  
Julius Olubumi Fasakin

The city of Akure has experienced rapid growth in the past 2 to 3 decades which has led to the expansion of the core urban areas of the city into adjoining rural lands. The paper analyses the urban growth of Akure using medium resolution Landsat imageries. Landsat (MSS), Landsat Thematic Mapping(TM) and Landsat Enhanced Thematic Mapper (ETM+) images for 1972, 1986 and 2002 respectively were used in a post-classification comparison analysis to map the spatial dynamic of land cover changes and identify the urbanization process in Akure. The land cover statistical results revealed a rapid growth in the built-up area of Akure from 997.2 hectares in 1972 to about 3852.70 hectares in 2002 due to increase in population of Akure within this period. Results of the prediction showed that the built-up area of the city has increased in size from 977.2 hectares in 1972 to 5863.66 hectares in 2022 corresponding to 500% at the rate of 13.1% per annum. Implications of growth include loss of open space, pressure on limited infrastructure, overcrowding, traffic congestion and poor standard of living. The study recommends regular monitoring of urban area, development of small towns around the city area to avoid overcrowding, training of planners and administrators to acquire more knowledge in the use of GIS and remote sensing to enhance efficiency.


Author(s):  
S. Shrestha

Abstract. Increasing land use land cover changes, especially urban growth has put a negative impact on biodiversity and ecological process. As a consequences, they are creating a major impact on the global climate change. There is a recent concern on the necessity of exploring the cause of urban growth with its prediction in future and consequences caused by this for sustainable development. This can be achieved by using multitemporal remote sensing imagery analysis, spatial metrics, and modeling. In this study, spatio-temporal urban change analysis and modeling were performed for Biratnagar City and its surrounding area in Nepal. Land use land cover map of 2004, 2010, and 2016 were prepared using Landsat TM imagery using supervised classification based on support vector machine classifier. Urban change dynamics, in term of quantity, and pattern was measured and analyzed using selected spatial metrics and using Shannon’s entropy index. The result showed that there is increasing trend of urban sprawl and showed infill characteristics of urban expansion. Projected land use land cover map of 2020 was modeled using cellular automata-based approach. The predictive power of the model was validated using kappa statistics. Spatial distribution of urban expansion in projected land use land cover map showed that there is increasing threat of urban expansion on agricultural land.


2021 ◽  
Vol 258 ◽  
pp. 09035
Author(s):  
Alexander Ischenko ◽  
Daria Shishkunova

In the modern world, urban areas are gradually replacing natural areas, which, in turn, negatively affects the environmental situation of the city. To solve this problem, people began to think about greening megalopolises in such a way that it did not occupy useful areas of the urban environment. The solution to this problem is possible by using vertical gardening technology in high-rise construction, which turns gray walls into vertical gardens. This technology allows not only decorating city streets, but also to significantly increase energy efficiency, create a natural environment, and have a positive impact on the psycho-emotional state of a person. This paper discusses various vertical gardening technologies for high-rise construction.


2018 ◽  
pp. 40
Author(s):  
Yadira Henríquez Tigrero

ResumenLa extracción de la sal en la puntilla se ha venido desarrollando desde 1763, y ha sido un motor económico y medio para proveer de recursos a familias que artesanalmente se dedicaban a ella. Las salinas de la Provincia de Santa Elena conforman un ecosistema en el que convivencomunidades vegetales y especies endémicas y constituyen uno de los paisajes naturales más singulares de la provincia.En la actualidad el paisaje salinero se ha visto reducido en las últimas décadas por la expansión urbana y la carencia de políticas de estado que contemplen su conservación. El presente trabajo de investigación muestra el análisis de la situación de las salinas marinas, emplazadas en la costa de la ciudad de Salinas, centrándose en los cambios que han presentadoen los últimos años, debido a los procesos de urbanización. Desde una perspectiva histórica y etnográfica se describe el funcionamiento y  métodos de extracción de la sal; para la identificación y clasificación de las salinas tanto industriales como artesanales. El estudio comprende lavariación en la extensión de las salinas, y si son contempladas en las estrategias de protección frente al crecimiento urbano en los instrumentos normativos municipales.AbstractSalt extraction in The Salinas has been developing since 1763 and has been an economic and an engine to provide resources to families who were handcrafted engaged in it. The Salina’s municipality make up an ecosystem in which plant communities and endemic species coexist andconstitute one of the most unique provinces’s natural landscapes.Today the salt landscape has been reduced in recent decades by urban expansion and the lack of State Policies that contemplate its conservation. This research paper shows the analysis of the the salt marshes’s situation, located on the coast of the city of Salinas, focusing on the changes theyhave presented in recent years, due to urbanization processes. From a historical and ethnographic perspective, the operation and methods of salt extraction are described, for the identification and classification of both industrial and handcrafted salt flats. The study comprises the variation in the extension of the Salinas, and if they are contemplated in the strategies of protection against the urban growth in the normative instruments of the municipality.Salinas as a city its contemplating the implementation of strategies for protection of these ecosystems against the urban growth in the normative instruments of the municipality.


Urban Science ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 10
Author(s):  
Mostapha Harb ◽  
Matthias Garschagen ◽  
Davide Cotti ◽  
Elke Krätzschmar ◽  
Hayet Baccouche ◽  
...  

Current rapid urbanization trends in developing countries present considerable challenges to local governments, potentially hindering efforts towards sustainable urban development. To effectively anticipate the challenges posed by urbanization, participatory modeling techniques can help to stimulate future-oriented decision-making by exploring alternative development scenarios. With the example of the coastal city of Monastir, we present the results of an integrated urban growth analysis that combines the SLEUTH (slope, land use, exclusion, urban extent, transportation, and hill shade) cellular automata model with qualitative inputs from relevant local stakeholders to simulate urban growth until 2030. While historical time-series of Landsat data fed a business-as-usual prediction, the quantification of narrative storylines derived from participatory scenario workshops enabled the creation of four additional urban growth scenarios. Results show that the growth of the city will occur at different rates under all scenarios. Both the “business-as-usual” (BaU) prediction and the four scenarios revealed that urban expansion is expected to further encroach on agricultural land by 2030. The various scenarios suggest that Monastir will expand between 127–149 hectares. The information provided here goes beyond simply projecting past trends, giving decision-makers the necessary support for both understanding possible future urban expansion pathways and proactively managing the future growth of the city.


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