scholarly journals Mapping and Characterizing Spatiotemporal Dynamics of Impervious Surfaces Using Landsat Images: A Case Study of Xuzhou, East China from 1995 to 2018

2019 ◽  
Vol 11 (5) ◽  
pp. 1224 ◽  
Author(s):  
Han Li ◽  
Long Li ◽  
Longqian Chen ◽  
Xisheng Zhou ◽  
Yifan Cui ◽  
...  
Keyword(s):  
Urban Planning ◽  
Urban Areas ◽  
East China ◽  
Impervious Surfaces ◽  
Landsat Images ◽  
Rapid Urbanization ◽  
Ecological Protection ◽  
Surface Expansion ◽  
Spectral Mixture

As an effective indicator of urbanization, impervious surfaces play a significant role in urban planning and ecological protection. It is, therefore, important to characterize impervious surfaces in urban geographical studies. As a key city in East China, Xuzhou has experienced rapid urbanization in recent decades and is now becoming an environmentally friendly city. To better understand the spatiotemporal heterogeneity of Xuzhou’s urban development, we extracted its impervious surfaces from Landsat images of 1995, 2003, 2010, and 2018 by a linear spectral mixture analysis. Then, a range of complementary methods including landscape indices, profile lines, median centers, standard deviational ellipses, and spatial autocorrelation were adopted to analyze the landscape pattern and expansion of impervious surfaces on both city and district scales. Results show that (1) there was a constant impervious surface expansion, originating in downtown Xuzhou; (2) promoting ecological protection in urban areas fragmented impervious surfaces with increasing heterogeneity and diversity overall; and (3) expansion directions and rates of impervious surfaces varied with district and town, and the central urban area expanded towards east and southeast, which could be related to their own resources and governmental policies. Findings from this study provide useful insights into urban planning of this economically prospective region.

scholarly journals Spatiotemporal Variance Assessment of Urban Rainstorm Waterlogging Affected by Impervious Surface Expansion: A Case Study of Guangzhou, China

2018 ◽  
Vol 10 (10) ◽  
pp. 3761 ◽  
Author(s):  
Huafei Yu ◽  
Yaolong Zhao ◽  
Yingchun Fu ◽  
Le Li
Keyword(s):  
Spatial Pattern ◽  
Urban Renewal ◽  
Impervious Surface ◽  
City Centre ◽  
Impervious Surfaces ◽  
Surface Expansion ◽  
The Impact ◽  
Gwr Model ◽  
Runoff Plots

Urban rainstorm waterlogging has become a typical “city disease” in China. It can result in a huge loss of social economy and personal property, accordingly hindering the sustainable development of a city. Impervious surface expansion, especially the irregular spatial pattern of impervious surfaces, derived from rapid urbanization processes has been proven to be one of the main influential factors behind urban waterlogging. Therefore, optimizing the spatial pattern of impervious surfaces through urban renewal is an effective channel through which to attenuate urban waterlogging risk for developed urban areas. However, the most important step for the optimization of the spatial pattern of impervious surfaces is to understand the mechanism of the impact of urbanization processes, especially the spatiotemporal pattern of impervious surfaces, on urban waterlogging. This research aims to elucidate the mechanism of urbanization’s impact on waterlogging by analysing the spatiotemporal characteristics and variance of urban waterlogging affected by urban impervious surfaces in a case study of Guangzhou in China. First, the study area was divided into runoff plots by means of the hydrologic analysis method, based on which the analysis of spatiotemporal variance was carried out. Then, due to the heterogeneity of urban impervious surface effects on waterlogging, a geographically weighted regression (GWR) model was utilized to assess the spatiotemporal variance of the impact of impervious surface expansion on urban rainstorm waterlogging during the period from the 1990s to the 2010s. The results reveal that urban rainstorm waterlogging significantly expanded in a dense and circular layer surrounding the city centre, similar to the impervious surface expansion affected by urbanization policies. Taking the urban runoff plot as the research unit, GWR has achieved a good modelling effect for urban storm waterlogging. The results show that the impervious surfaces in the runoff plots of the southeastern part of Yuexiu, the southern part of Tianhe and the western part of Haizhu, which have experienced major urban engineering construction, have the strongest correlation with urban rainstorm waterlogging. However, for different runoff plots, the impact of impervious surfaces on urban waterlogging is quite different, as there exist other influence factors in the various runoff plots, although the impervious surface is one of the main factors. This result means that urban renewal strategy to optimize the spatial pattern of impervious surfaces for urban rainstorm waterlogging prevention and control should be different for different runoff plots. The results of the GWR model analysis can provide useful information for urban renewal strategy-making.

scholarly journals Spatial–Temporal Impacts of Urban Sprawl on Ecosystem Services: Implications for Urban Planning in The Process of Rapid Urbanization

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1210
Author(s):  
Xiaoyan Li ◽  
Gulinaer Suoerdahan ◽  
Zhenyu Shi ◽  
Zihan Xing ◽  
Yongxing Ren ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Urban Planning ◽  
Carbon Storage ◽  
Crop Yield ◽  
Urban Sprawl ◽  
Habitat Suitability ◽  
Urban Areas ◽  
Water Retention ◽  
Rapid Urbanization ◽  
Study Region

Rapid urbanization drives land cover change, affecting urban ecosystems and inducing serious environmental issues. The study region of Changchun, China was divided into three urbanization categories according to different urbanization levels and the characteristics of urban sprawl and changes and relationships between typical ecosystem services (ESs) under rapid urbanization were analysed. The results showed that Changchun has undergone considerable urban expansion since 2000, which has significantly impacted all ESs in terms of spatial and temporal heterogeneity. Habitat suitability and crop yield have relatively stronger service capacity in the study area. Since the expansion of large-scale infrastructures, the mean ES values of developed urban areas are the lowest among the three zones, except for water retention and sandstorm prevention in 2015, when the balance between all services decreased. Over the past 16 years, habitat suitability in developing urban areas has decreased to a large extent due to urban sprawl. Because of the improvement in agricultural science and technology, crop yield in three regions increased, while the area of cropland reduced from 1720 km2 to 1560 km2 (9.3%). Synergies between habitat suitability and carbon storage and habitat suitability and soil retention were detected in three areas. A trade-off between habitat suitability and water retention was detected in three areas. The interactions between crop yield and carbon storage, habitat suitability, and soil retention were more complex in this study region. In addition to water retention, urbanization index has a negative correlation with ESs. According to the results, some suggestions to alleviate ES loss during the process of rapid urbanization were proposed, which may guide scientific urban planning for sustainable urban development.

Detection of Urban Expansion by Using DMSP-OLS, Landsat Data and Linear Spectral Unmixing Method

2019 ◽  
pp. 1372-1382
Author(s):  
Cihan Uysal ◽  
Derya Maktav
Keyword(s):  
Urban Growth ◽  
Urban Areas ◽  
Urban Expansion ◽  
Dynamic Structure ◽  
Spectral Unmixing ◽  
Landsat Images ◽  
Green Vegetation ◽  
Linear Mixture Model ◽  
Linear Spectral Unmixing ◽  
Spectral Mixture

Urbanization has been increasingly continuing in Turkey and in the world for the last 30 years. Especially for the developing countries, urbanization is a necessary fact for the sustainability of the urban growth. Yet, this growth should be controlled and planned; otherwise, many environmental problems might occur. Therefore, the urban areas having dynamic structure should be monitored periodically. Monitoring the changes in urban environment can be provided with land cover land use (LCLU) maps produced by the pixel based classification methods using ‘maximum likelihood' and ‘isodata' techniques. However, these thematic maps might bring about inaccurate classification results in heterogeneous areas especially where low spatial resolution satellite data is used since, in these approaches, each pixel is represented with only one class value. In this study, considering the spectral mixture analysis (SMA) each pixel is represented by endmember fractions. The earth is represented more accurately using 'substrate (S)', ‘green vegetation (V)' and ‘dark surfaces (D)' spectral endmember reflectances with this analysis based on linear mixture model. Here, the surrounding of Izmit Gulf, one of the most industrialized areas of Turkey, has been chosen as the study area. SMA has been applied to LANDSAT images of the years of 1984, 1999 and 2009. In addition, DMSP-OLS data of 1992, 1999 and 2009 has been used to detect urban areas. According to the results, the changes in LCLU and especially the urban growth areas have been detected accurately using the SMA method.

scholarly journals Smart Urban Planning: Evaluating Urban Logistics Performance of Innovative Solutions and Sustainable Policies in the Venice Lagoon—the Results of a Case Study

2019 ◽  
Vol 11 (17) ◽  
pp. 4580 ◽  
Author(s):  
Marco Mazzarino ◽  
Lucio Rubini
Keyword(s):  
Urban Planning ◽  
Urban Areas ◽  
Urban Sustainability ◽  
Venice Lagoon ◽  
Urban Transport ◽  
Urban Systems ◽  
Transport Capacity ◽  
Urban Network ◽  
Urban Freight

Currently, remarkable gaps of operational, social and environmental efficiency and overall sub-optimization of the logistics and mobility systems exist in urban areas. There is then the need to promote and assess innovative transport solutions and policy-making within SUMPs (Sustainable Urban Mobility Plans) to deal with such critical issues in order to improve urban sustainability. The paper focuses on the case study of the Venice Lagoon, where islands—despite representing a relevant feature of urban planning—face a tremendous lack of accessibility, depopulation, social cohesion and they turn out to be poorly connected. By developing an original scenario-building methodological framework and performing data collection activities, the purpose of the paper consists of assessing the feasibility of a mixed passenger and freight transport system —sometimes called cargo hitching. Mixed passenger and freight systems/cargo hitching are considered as an innovative framework based on the integration of freight and passenger urban systems and resources to optimize the existing transport capacity, and thus, urban sustainability. Results show that the overall existing urban transport capacity can accommodate urban freight flows on main connections in the Lagoon. The reduction in spare public transport capacity, as well as in the number (and type) of circulating freight boats show—in various scenarios—the degree of optimization of the resulting urban network configuration and the positive impacts on urban sustainability. This paves the way for the regulatory framework to adopt proposed solutions.

Temporary versus Permanent Population Mobility in Melanesia: A Case Study from Vanuatu

1992 ◽  
Vol 26 (3) ◽  
pp. 806-842 ◽  
Author(s):  
Gerald Haberkorn
Keyword(s):  
Urban Areas ◽  
Total Population ◽  
Direct Result ◽  
Population Mobility ◽  
Rapid Urbanization ◽  
Predominant Form ◽  
Recent Developments ◽  
Contemporary Reality

Melanesia's urban population tripled from a mere 7 percent of the region's total population in 1955 to 20 percent by 1985. The recency and magnitude of this development and the absence of any established forms of urban living in the region's precolonial history virtually rules out natural population growth as the principal cause behind this process of rapid urbanization and suggests massive internal population mobility as the most likely cause. The overall picture conveyed by the Melanesian mobility literature, however, emphasizes rural-based circular mobility as the predominant form of population mobility in the region. Seeking to reconcile this contrast, this article argues that much of the alleged continued predominance of circular mobility owes more to its underlying operationalizations, ways of measurement, and theoretical conceptualizations than reflects contemporary reality. This argument is substantiated by an analysis of recent developments in Vanuatu mobility set in the local and historical conditions of migration from the island of Paama. It is demonstrated how specific structural transformations on the island and in urban areas throughout this century were not only conducive to a change from temporary to long-term or permanent rural absences, but how they also have emerged as the direct result of mobility, thus highlighting the latter's dialectical nature. Evidence for this mobility change is derived from a comparative analysis of lifetime mobility histories of urban and rural Paamese men and women.

scholarly journals CONTINUOUS CHANGE DETECTION OF URBAN LAKES IN WUHAN, CHINA USING MULTI-TEMPORAL REMOTE SENSING IMAGES

2018 ◽  
Vol XLII-3 ◽  
pp. 2315-2320
Author(s):  
W. Zhang ◽  
X. Kong ◽  
G. Tan ◽  
S. Zheng
Keyword(s):  
Change Detection ◽  
Urban Areas ◽  
Central Area ◽  
Strong Impact ◽  
Continuous Change ◽  
Landsat Images ◽  
Rapid Urbanization ◽  
Urban Lakes ◽  
Multi Temporal ◽  
Lake Change

Urban lakes are important natural, scenic and pattern attractions of the city, and they are potential development resources as well. However, lots of urban lakes in China have been shrunk significantly or disappeared due to rapid urbanization. In this study, four Landsat images were used to perform a case study for lake change detection in downtown Wuhan, China, which were acquired on 1991, 2002, 2011 and 2017, respectively. Modified NDWI (MNDWI) was adopted to extract water bodies of urban areas from all these images, and OTSU was used to optimize the threshold selection. Furthermore, the variation of lake shrinkage was analysed in detail according to SVM classification and post-classification comparison, and the coverage of urban lakes in central area of Wuhan has decreased by 47.37&amp;thinsp;km<sup>2</sup> between 1991 and 2017. The experimental results revealed that there were significant changes in the surface area of urban lakes over the 27 years, and it also indicated that rapid urbanization has a strong impact on the losses of urban water resources.

scholarly journals Trends in Extreme Temperatures in Relation to Urbanization in the Twin Cities Metropolitan Area, Minnesota

2009 ◽  
Vol 48 (3) ◽  
pp. 669-679 ◽  
Author(s):  
Shouraseni Sen Roy ◽  
Fei Yuan
Keyword(s):  
Metropolitan Area ◽  
Urban Areas ◽  
Extreme Temperature ◽  
Simultaneous Increase ◽  
Twin Cities ◽  
Extreme Temperatures ◽  
Impervious Surfaces ◽  
Landsat Images ◽  
Rural And Urban Areas ◽  
Rate Of Increase

Abstract The long-term trends in extreme summer season temperatures across the Twin Cities Metropolitan Area (TCMA) associated with urbanization are examined. To assess trends in extreme temperature data, maximum and minimum temperatures from 1975 to 2002 were assembled for seven stations located in both rural and urban areas. Furthermore, urbanization since 1975 was assessed by estimating the percentage of impervious surfaces from Landsat images acquired for various years. The results of this study indicated a greater rate of increase in overall minimum temperatures, resulting in a slightly declining trend in diurnal temperature range for all of the stations. In the case of extreme temperatures, most of the peripheral urban and rural stations experienced negative trends in extreme maximum temperatures, accompanied by positive trends in extreme minimum temperatures. This was also validated by the simultaneous increase in the percentage of impervious surfaces in those locations. The greatest changes were observed for Stillwater, which is located relatively close to the heart of the TCMA but has undergone a faster rate of urbanization.

scholarly journals STREET TRADE AND THE ATTAINMENT OF URBAN RESILIENCE AND ADAPTATION IN LAGOS, NIGERIA

2018 ◽  
Vol 24 (1) ◽  
pp. 1-9
Author(s):  
Ademola Omoegon
Keyword(s):  
Public Space ◽  
Working Conditions ◽  
Informal Economy ◽  
Urban Areas ◽  
Urban Governance ◽  
Urban Resilience ◽  
Rapid Urbanization ◽  
Significant Damage ◽  
Development Policies

Rapid urbanization rates and the proliferation of informal activities in vulnerable locations present significant challenges to urban resilience and adaptation, particularly in cities seeking to reduce poverty and improve economic growth. Inclusive urban governance has been identified as being vital to building resilience. Informal employment is the life blood of African cities, as evidenced by the multitude of street traders which abound in urban areas. However, in recent times many city authorities in Africa have adopted neo-liberal development policies which have led to the sanitization of public space and displacement of street traders, as well as a consequent worsening of the already precarious working conditions of traders and a significant damage of their limited associational structure, thus reducing their capacity to participate in urban governance. Through a case study of Lagos, Nigeria which possesses the largest informal economy in Africa, this paper examines the challenges which associations of the working poor face and the effect of this on urban resilience efforts. By exploring the experiences of street traders, the paper aims to investigate their current forms of organisation, their role in urban governance and how these factors can enhance or hinder urban resilience and adaptation. Keywords: Street trade, urban resilience, informal economy, urban governance, Lagos

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