scholarly journals Urban correction of global DEMs using building density for Nairobi, Kenya

2021 ◽  
Author(s):  
Victor Olajubu ◽  
Mark A. Trigg ◽  
Christian Berretta ◽  
Andrew Sleigh ◽  
Marco Chini ◽  
...  
Keyword(s):  
Urban Areas ◽  
Central Business District ◽  
Global Scale ◽  
Urban Flood ◽  
Building Density ◽  
Building Height ◽  
Local Reference ◽  
Business District ◽  
Height Data ◽  
Vertical Height

AbstractUrban flood models that use Digital Elevation Models (DEMs) to simulate extent and depth of flood inundation rely on the accuracy of DEMs for predicting flood events. Despite recent advances in developing vegetation corrected DEMs, the effect of building height and density errors in global DEMs in urban areas are still poorly understood, and their correction remains a challenge. In this research we developed a methodology for building error correction that can be applied to any other case study, where building density data and a local reference DEM data are available. This methodology was applied to Nairobi, Kenya using six global DEMs (SRTM, MERIT, ALOS, NASADEM, TanDEM-X 12 m, and TanDEM-X 90 m DEM). Our results show building error at highest building density varying between 1.25 m and 5.07 m for the DEMs used, with the MERIT DEM showing the smallest vertical height error from the reference DEM. The six DEMs were corrected by deriving a linear relationship between building density and DEM error. Our findings show that the removal of building density error resulted in the improvement of the vertical height accuracy of the global DEMs of up to 45% for MERIT and 40% for ALOS. This methodology was also applied to the Central Business District (CBD) area of Nairobi, characterized by taller buildings and high building density. The error parameters in the CBD area resulted to be between 15 to 45% higher than those of the Nairobi city wide area for the six global DEMs, thus providing further insights into the contribution of building heights to errors in global DEMs. Building height data is still unavailable on a global scale and our results show that global DEMs can be usefully corrected for building density errors in urban areas, even where specific building height data are not available.

scholarly journals Leveraging machine learning to produce a cost-effective national building height map of Ireland

2021 ◽  
Author(s):  
Eoghan Keany ◽  
Geoffrey Bessardon ◽  
Emily Gleeson
Keyword(s):  
Machine Learning ◽  
Remote Sensing ◽  
High Resolution ◽  
Land Cover ◽  
Urban Areas ◽  
Cost Effective ◽  
Land Cover Classification ◽  
National Scale ◽  
Building Height ◽  
Height Data

<p>To represent surface thermal, turbulent and humidity exchanges, Numerical Weather Prediction (NWP) systems require a land-cover classification map to calculate sur-face parameters used in surface flux estimation. The latest land-cover classification map used in the HARMONIE-AROME configuration of the shared ALADIN-HIRLAMNWP system for operational weather forecasting is ECOCLIMAP-SG (ECO-SG). The first evaluation of ECO-SG over Ireland suggested that sparse urban areas are underestimated and instead appear as vegetation areas (1). While the work of (2) on land-cover classification helps to correct the horizontal extent of urban areas, the method does not provide information on the vertical characteristics of urban areas. ECO-SG urban classification implicitly includes building heights (3), and any improvement to ECO-SG urban area extent requires a complementary building height dataset.</p><p>Openly accessible building height data at a national scale does not exist for the island of Ireland. This work seeks to address this gap in availability by extrapolating the preexisting localised building height data across the entire island. The study utilises information from both the temporal and spatial dimensions by creating band-wise temporal aggregation statistics from morphological operations, for both the Sentinel-1A/B and Sentinel-2A/B constellations (4). The extrapolation uses building height information from the Copernicus Urban Atlas, which contains regional coverage for Dublin at 10 m x10 m resolution (5). Various regression models were then trained on these aggregated statistics to make pixel-wise building height estimates. These model estimates were then evaluated with an adjusted RMSE metric, with the most accurate model chosen to map the entire country. This method relies solely on freely available satellite imagery and open-source software, providing a cost-effective mapping service at a national scale that can be updated more frequently, unlike expensive once-off private mapping services. Furthermore, this process could be applied by these services to reduce costs by taking a small representative sample and extrapolating the rest of the area. This method can be applied beyond national borders providing a uniform map that does not depends on the different private service practices facilitating the updates of global or continental land-cover information used in NWP.</p><p> </p><p>(1) G. Bessardon and E. Gleeson, “Using the best available physiography to improve weather forecasts for Ireland,” in Challenges in High-Resolution Short Range NWP at European level including forecaster-developer cooperation, European Meteorological Society, 2019.</p><p>(2) E. Walsh, et al., “Using machine learning to produce a very high-resolution land-cover map for Ireland, ” Advances in Science and Research,  (accepted for publication).</p><p>(3) CNRM, "Wiki - ECOCLIMAP-SG" https://opensource.umr-cnrm.fr/projects/ecoclimap-sg/wiki</p><p>(4) D. Frantz, et al., “National-scale mapping of building height using sentinel-1 and sentinel-2 time series,” Remote Sensing of Environment, vol. 252, 2021.</p><p>(5) M. Fitrzyk, et al., “Esa Copernicus sentinel-1 exploitation activities,” in IGARSS 2019-2019 IEEE International Geoscience and Remote Sensing Symposium, IEEE, 2019.</p>

scholarly journals Analyzing the Issue of On-street Parking in Commercial Areas: A Case Study of the City of Hyderabad, Pakistan

2018 ◽  
Vol 01 (02) ◽  
pp. 01-09
Author(s):  
Baig Farrukh ◽  
Sahito Noman ◽  
Bano Arsla ◽  
Keyword(s):  
Traffic Congestion ◽  
Urban Areas ◽  
Survey Methodology ◽  
Greenhouse Gas Emission ◽  
Central Business District ◽  
Rapid Urbanization ◽  
Analysis Technique ◽  
Business District ◽  
Public Views ◽  
The City

In developing countries, rapid urbanization has created an enormous pressure on land use, infrastructure and transportation. The fast growing ratio of motorized vehicles in urban areas is the main cause of environmental degradation. Almost 80% of the greenhouse gas emission is from vehicles in cities. In the city centers, on-street parking is considered the major cause of traffic congestion. The aim of this study was to evaluate the problems of on-street parking and disorderly parking at Central Business District (CBD) of Hyderabad city. The field survey methodology was adopted to perceive the current traffic problems in the city center and traffic count survey was carried out in both peak and off hours. The data was analyzed using descriptive statistics frequency analysis technique with the help of Statistical Package for the Social Sciences (SPSS). The findings revealed that increasing number of vehicles, on-street parking, improper parking, encroachment, inadequate parking space and poor condition of roads are the main causes of traffic congestion. The study bridges up the research gap of determining public views about on-street parking challenges in the context of Hyderabad, Pakistan and provides statistical results which may equally be adapted by policy makers and transportation planners in order to improve the traffic situation.

Calibrating Pedestrian Level-of-Service Metrics with 3-D Visualization

2000 ◽  
Vol 1705 (1) ◽  
pp. 9-15 ◽  
Author(s):  
John S. Miller ◽  
Jeremy A. Bigelow ◽  
Nicholas J. Garber
Keyword(s):  
Urban Areas ◽  
Rating Scales ◽  
Central Business District ◽  
Level Of Service ◽  
Analysis Tool ◽  
Highway Capacity Manual ◽  
Pedestrian Level Of Service ◽  
Walking Environment ◽  
Business District ◽  
Pedestrian Crossing

Unlike the case with airport terminals or the central business district, the quality of suburban pedestrian facilities is most likely affected less by congestion and more by safety, the walking environment, and aesthetics. Because the Highway Capacity Manual does not explicitly capture such factors when measuring pedestrian level of service (LOS), researchers have proposed innovative rating scales that do. These scales use either measurable characteristics, such as walkway width, median openings, and signalization parameters, or user perceptions, such as continuity and convenience, to rate a pedestrian facility. Unfortunately, the results of these scales are not always easy to interpret. For example, in a scaling system for pedestrian facilities in which a raised curb median counts 6 points and a blinking pedestrian-crossing signal counts 3 points, the developers of the scale believed that the median would be twice as valuable to pedestrians as the crossing signal. But would pedestrians agree? A scaling system was developed for pedestrian LOS and calibrated using visualization (computer-aided modeling techniques consisting of still shots and animations). Subjects’ perceived ratings of a pedestrian facility after they viewed still pictures and animations of the facility were compared with the computed rating of the facility from an LOS scale. The chief value of this method is that it helps ensure that pedestrian crossing needs are systematically considered and that engineers, planners, and the public agree on the calibration of a pedestrian LOS scale. The methodology is also applicable in urban areas where pedestrian needs beyond physical capacity are to be explicitly considered. The approach is original in that visualization as a simulation and data analysis tool was used to calibrate a pedestrian LOS scale.

scholarly journals PUSAT INTEGRASI AGRIKULTUR DI BUMI SERPONG DAMAI

2020 ◽  
Vol 1 (2) ◽  
pp. 2037
Author(s):  
Yunior Dharma Aryindra ◽  
Petrus Rudi Kasimun
Keyword(s):  
Production Process ◽  
Urban Areas ◽  
Food Production ◽  
Agricultural Land ◽  
Urban Community ◽  
Central Business District ◽  
Agricultural Technologies ◽  
City Life ◽  
The Government ◽  
Business District

The government has the idea to develop a Modern Agricultural Zone in BSD (Bumi Serpong Damai) covering an area of 36ha which can support for 700ha of agricultural land around the area. We need a place where producers, consumers and the public can gather together to explore, develop and share experiences in the food production system in urban area. This will be great first movement for the next greater movement so that agriculture can merge into city-life and become a daily life for the urban community. Agricultural Hub in BSD has potentiallity to reduce barriers between consumers and producers which usually take long times cyclus because production activies are carried in the villages and sales in urban areas, but with this Agricultral Hub we can break the long chain so it can create a sustainable and efficient cyclus. Because this building located in the middle of the city, it provides direct education for the urban community about agriculture and the renewal and development of agricultural technologies. Agricultural Hub in Bumi Serpong Damai operates with a number of main programs whose serving and providing all cyclus of the food production process to reach consumers. Starting from production, process, cooking to sales available in here, plus there are research facilities and offices for young start-ups who want to enter the world of agriculture. Located in the CBD (Central Business District) of BSD and directly adjacent to agricultural land makes Agricultural Hub in Bumi Serpong Damai a connector between urban areas and agricultural land, which make benefit to the areas. AbstrakPemerintah memiliki gagasan untuk mengembangkan Kawasan Pertanian Modern di BSD (Bumi Serpong Damai) seluas 36 Ha yang dapat memberikan dukungan terhadap lahan pertanian seluas 700 Ha di sekitar kawasan tersebut. Oleh karena itu, dibutuhkan wadah produsen kota. Pusat Integrasi Agrikultur memiliki potensi dirancang untuk mengurangi hambatan antara konsumen dan produsen yang biasanya berlangsung secara berjenjang dan panjang namun dengan adanya pusat ini dapat memutuskan rantai tersebut sehingga dapat menciptakan iklim yang berkelanjutan dan efisien. Serta dengan letaknya yang berada di tengah kota memberikan edukasi secara langsung bagi masyarakat kota mengenai apa itu pertanian serta pembaharuan dan pengembangan teknologi-teknologi pertanian. Pusat Integrasi Agrikultur di Bumi Serpong Damai beroperasi dengan beberapa program utama yang sifatnya melayani dan menyediakan semua  tahapan proses produksi pangan hingga sampai ke tangan konsumen. Dimulai dari produksi, proses, memasak hingga penjualan tersedia disini ditambah dengan adanya fasilitas riset dan kantor bagi start-up muda yang ingin masuk ke dalam dunia agrikultur juga tersedia di sini. Dengan lokasi yang berada di kawasan CBD (Central Business District) BSD serta berbatasan langsung dengan lahan pertanian menjadikan Pusat Integrasi Agrikultur sebagai konektor antara kawasan perkotaan dan lahan pertanian, yang tidak memutus tetapi menyambungkan antar keduanya.

scholarly journals The impact on urban accessibility conditions of a proposed cableway line in the city of Manizales, Colombia

2021 ◽  
Vol 51 (51) ◽  
pp. 95-107
Author(s):  
Jorge Alberto Montoya ◽  
Juan Camilo Aguilera ◽  
Diego Alexander Escobar
Keyword(s):  
Urban Areas ◽  
Central Business District ◽  
Environmentally Sustainable ◽  
Public Transport System ◽  
Average Travel Time ◽  
Urban Accessibility ◽  
Business District ◽  
The Impact ◽  
The City

Abstract Due to the increased tendency to use private transport in urban areas of Manizales and Villamaría municipalities, it is intended to include alternative modes of transport that are more time-efficient and environmentally sustainable to improve the inhabitants’ quality of life. This article aims to analyse the inclusion impact of a sustainable public transport system, such as a new cableway line in the city connecting the Central Business District (CBD) with Ciudadela del Norte district, measuring overall average accessibility for the current and future scenario. This establishes the average travel time and the savings in terms of time shown as a percentage that these modes of transport would create in the population displacement and also which inhabitants are the most likely to benefit.

scholarly journals KONSEP WALKABILITY INDEX DAN PENANGANAN FASILITAS PEJALAN KAKI PADA KAWASAN JALAN PERKOTAAN DI INDONESIA

2020 ◽  
Vol 4 (1) ◽  
pp. 12
Author(s):  
Dwiky Erlangga ◽  
Dewi Handayani ◽  
Syafi'i Syafi'i
Keyword(s):  
Urban Areas ◽  
Rapid Development ◽  
Central Business District ◽  
Public Works ◽  
Literature Study ◽  
Scoring Method ◽  
Walkability Index ◽  
Main Components ◽  
Business District

<p>Walkability Index (WI) is a method to assess the walkability level on pedestrian facilities with the main components of: safety and security, convinience and attractiveness, as well as government policies. Generally, this method is utilized to review the pedestrian facilities walkability in urban areas, particularly in CBD (Central Business District) which is the hub for activities center, such as economic, business, education, healthcare, transit to tourism areas. The rapid development of activities leads to the increasing number of visitors in those areas, such as on Jalan Slamet Riyadi, Surakarta. This condition needs to be balanced with the availability of adequate facilities and infrastructure, one of them is the sidewalks to facilitate the pedestrian movement from one place to another. Indonesia did not have any assessment criteria for sidewalks in terms of scoring even though<em> </em>some variables on WI have already existed in the Circular Letter of the Minister of Public Works and Public Housing 02/SE/M/2018 on the Guidelines for Pedestrian Facility Planning. This paper presents the recommendation of assesment and category based on the regulation in Indonesia. It is expected to benefit the determination of priority on pedestrian facility handling in the field. Literature study as the foundation of this paper attempts to accomodate the pedestrian facility variables contained in the regulation of Indonesia using the scoring method with several recommendations in the category of handling, with the basis of WI analysis method. The results of the analysis show that there are 3 variables that need to be considered more in the planning criteria for sidewalk in Indonesia that affect the determination of handling recommendation including the supporting and additional facilities, facilities for disabled pedestrians, and the needs of wide space for pedestrians.</p>

scholarly journals Urban attractors: Discovering patterns in regions of attraction in cities

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250204
Author(s):  
May Alhazzani ◽  
Fahad Alhasoun ◽  
Zeyad Alawwad ◽  
Marta C. González
Keyword(s):  
Urban Areas ◽  
Clustering Algorithm ◽  
Statistical Significance ◽  
Central Business District ◽  
Statistical Significance Testing ◽  
Spatial Spread ◽  
The Road ◽  
On The Road ◽  
Business District ◽  
The City

Understanding the dynamics by which urban areas attract visitors is important in today’s cities that are continuously increasing in population towards higher densities. Identifying services that relate to highly attractive districts is useful to make policies regarding the placement of such places. Thus, we present a framework for classifying districts in cities by their attractiveness to daily commuters and relating Points of Interests (POIs) types to districts’ attraction patterns. We used Origin-Destination matrices (ODs) mined from cell phone data that capture the flow of trips between each pair of places in Riyadh, Saudi Arabia. We define the attraction profile for a place based on three main statistical features: The number of visitors a place received, the distribution of distance traveled by visitors on the road network, and the spatial spread of locations from where trips started. We used a hierarchical clustering algorithm to classify all places in the city by their features of attraction. We discovered three main types of Urban Attractors in Riyadh during the morning period: Global, which are significant places in the city, Downtown, which contains the central business district, and Residential attractors. In addition, we uncovered what makes districts possess certain attraction patterns. We used a statistical significance testing approach to quantify the relationship between Points of Interests (POIs) types (services) and the patterns of Urban Attractors detected.

scholarly journals Comparing the Impacts of Location Attributes on Residents’ Preferences and Residential Values in Compact Cities: A Case Study of Hong Kong

2020 ◽  
Vol 12 (12) ◽  
pp. 4867
Author(s):  
Yunxi Bai ◽  
Jusheng Song ◽  
Shanshan Wu ◽  
Wei Wang ◽  
Jacqueline T. Y. Lo ◽  
...  
Keyword(s):  
Hong Kong ◽  
Urban Areas ◽  
Housing Prices ◽  
Central Business District ◽  
Policy Formation ◽  
Hedonic Price ◽  
Policy Makers ◽  
Extensive Body ◽  
Business District ◽  
Housing Attributes

In recent years, environmentally-friendly, sustainable, and compact development has become increasingly popular with governments. An extensive body of literature has focused on the influence on housing prices from an economic perspective. Although residential urban planning from the perspective of individual needs must be considered, little attention has been paid to residents’ demands in high-density and compact urban areas. In this study, we selected Hong Kong as the case and adopted a reliability interval method to rank residential attitude metrics, which indicated residents’ neighborhood needs in densely populated cities. The influences of location attributes on residents’ demands and residential value were compared. A hedonic price model was used to estimate the impacts of the attributes on housing prices. The results showed that both access to metro stations and median household income had important influences on residents’ preferences and housing prices. However, access to the central business district contributed largely to housing prices but not to residents’ attitudes. These findings support urban planners and policy makers during sustainable residential planning and policy formation by understanding residents’ needs in compact urban areas, help them to optimize the match between housing attributes and residents’ expectations, and balance the relationship between residents’ needs and economic interest.

scholarly journals Implementasi Teori Asiatica Euphoria McGee Dalam Pengembangan Zona Industri Studi Kasus: Desa Bajera, Kecamatan Selemadeg, Kabupaten Tabanan, Bali

2020 ◽  
Vol 2 (1) ◽  
pp. 1-8
Author(s):  
Ni Putu Suda Nurjani
Keyword(s):  
Urban Areas ◽  
Central Business District ◽  
Industrial Estates ◽  
The Core ◽  
Basic Transformation ◽  
Core Areas ◽  
To Come ◽  
Business District ◽  
Industrial Zones ◽  
The City

Cities in Indonesia were initially formed through the transformation of various influences of power and power. Strength as an identity that can attract the outermost area to come to an area, while power lies in the personal strength of man as the leader of a region. These conditions have an impact on the development of the world of industry in the country. Transforming traditional city structures into a modern city, not only physically but also a basic transformation towards the concept of urbanity of its citizens. The urban village as an element of the city which is the identity of a region, still holds a traditional urbanity value system that is different from the conception of modern urbanity. This condition affects the development of industrial zones, such as what happened in Bajera Village, Selemadeg District, Tabanan Regency. The heterogeneity of the population of Bajera Village is one of the biggest indicators of the formation of an industrial zone. The existence of a transportation mode that connects the outermost areas of Bajera with the Core of Bajera Village is another driving factor that influences the growth of industrial estates. This study tried to explain descriptively qualitatively, a fact of regional development based on Asiatica Euphoria McGee's theory. The special attraction in the core of Bajera Village encourages residents in the outermost areas of Bajera to migrate to the core areas of Bajera Village with the aim of staying temporarily and to settle for long periods of time. This phenomenon is in line with the theory put forward by McGee, that the CBD (central business district) is formed due to the attraction of the core (core) and the ease of modes of transportation from peri urban areas to the CBD. This condition makes Bajera village the center of industrial and trade areas in the Selemadeg Barat region, Tabanan, Bali.

scholarly journals Centripetal Cities: Using Big Data to Measure Job-Housing Separation Based on Employment-Residence-Commuting Trade-off

2020 ◽  
Author(s):  
Ming Lu ◽  
Chong Peng
Keyword(s):  
Big Data ◽  
Urban Areas ◽  
Service Industry ◽  
Housing Prices ◽  
Housing Price ◽  
Central Business District ◽  
Urban Centers ◽  
Trade Off ◽  
Large Cities ◽  
Business District

Abstract With the advent of postindustrial society, populations are becoming increasingly concentrated in large cities, especially in urban centers. Here we study the “centripetal city” phenomenon. With many new service-industry jobs concentrated in central cities, people face the trade-off between employment, residence, and commuting. Using multisource big data from Shanghai, China, we develop a new job–housing separation index to reflect the trade-off between employment, housing price and commuting. We demonstrate that residents in central urban areas within a radius of approximately 20 km from the central business district tolerate job–housing separation in exchange for lower housing prices. Recent data indicate that job–housing separation accounts for 20% of housing prices. Our framework outperforms previous metrics, which not only provides a basis for understanding the formation and evolution of spatial structure in large cities, but can also guide wise planning and managing interventions for the United Nations Sustainable Development Goals.

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