scholarly journals Impact of Urbanization and Climate on Vegetation Coverage in the Beijing–Tianjin–Hebei Region of China

2019 ◽  
Vol 11 (20) ◽  
pp. 2452 ◽  
Author(s):  
Qian Zhou ◽  
Xiang Zhao ◽  
Donghai Wu ◽  
Rongyun Tang ◽  
Xiaozheng Du ◽  
...  
Keyword(s):  
Urban Areas ◽  
Core Area ◽  
Vegetation Coverage ◽  
Effect Of Temperature ◽  
Environment Change ◽  
Regional Environment ◽  
Rapid Urbanization ◽  
Important Indicator ◽  
Artificial Surface ◽  
Bth Region

Worldwide urbanization leads to ecological changes around urban areas. However, few studies have quantitatively investigated the impacts of urbanization on vegetation coverage so far. As an important indicator measuring regional environment change, fractional vegetation cover (FVC) is widely used to analyze changes in vegetation in urban areas. In this study, on the basis of a partial derivative model, we quantified the effect of temperature, precipitation, radiation, and urbanization represented as nighttime light on vegetation coverage changes in the Beijing–Tianjin–Hebei (BTH) region during its period of rapid resident population growth from 2001 to 2011. The results showed that (1) the FVC of the BTH region varied from 0.20 to 0.26, with significant spatial heterogeneity. The FVC increased in small cities such as Cangzhou and in the Taihang Mountains, while it decreased in megacities with populations greater than 1 million, such as Beijing and Zhangjiakou Bashang. (2) The BTH region experienced rapid urbanization, with the area of artificial surface increasing by 18.42%. From the urban core area to the fringe area, the urbanization intensity decreased, but the urbanization rate increased. (3) Urbanization and precipitation had the greatest effect on FVC changes. Urbanization dominated the FVC changes in the expanded area, while precipitation had the greatest impacts on the FVC changes in the core area. For future studies on the major influencing factors of FVC changes, quantitative analysis of the contribution of urbanization to FVC changes in urban regions is crucial and will provide scientific perspectives for sustainable urban planning.

scholarly journals URBAN BOUNDARY EXTRACTION AND URBAN SPRAWL MEASUREMENT USING HIGH-RESOLUTION REMOTE SENSING IMAGES: A CASE STUDY OF CHINA’S PROVINCIAL

2018 ◽  
Vol XLII-3 ◽  
pp. 1713-1719 ◽  
Author(s):  
H. Wang ◽  
X. Ning ◽  
H. Zhang ◽  
Y. Liu ◽  
F. Yu
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Urban Sprawl ◽  
Urban Areas ◽  
Remote Sensing Images ◽  
Boundary Extraction ◽  
Rapid Urbanization ◽  
Important Indicator ◽  
Provincial Capital ◽  
Year 2000

Urban boundary is an important indicator for urban sprawl analysis. However, methods of urban boundary extraction were inconsistent, and construction land or urban impervious surfaces was usually used to represent urban areas with coarse-resolution images, resulting in lower precision and incomparable urban boundary products. To solve above problems, a semi-automatic method of urban boundary extraction was proposed by using high-resolution image and geographic information data. Urban landscape and form characteristics, geographical knowledge were combined to generate a series of standardized rules for urban boundary extraction. Urban boundaries of China’s 31 provincial capitals in year 2000, 2005, 2010 and 2015 were extracted with above-mentioned method. Compared with other two open urban boundary products, accuracy of urban boundary in this study was the highest. Urban boundary, together with other thematic data, were integrated to measure and analyse urban sprawl. Results showed that China’s provincial capitals had undergone a rapid urbanization from year 2000 to 2015, with the area change from 6520 square kilometres to 12398 square kilometres. Urban area of provincial capital had a remarkable region difference and a high degree of concentration. Urban land became more intensive in general. Urban sprawl rate showed inharmonious with population growth rate. About sixty percent of the new urban areas came from cultivated land. The paper provided a consistent method of urban boundary extraction and urban sprawl measurement using high-resolution remote sensing images. The result of urban sprawl of China’s provincial capital provided valuable urbanization information for government and public.

scholarly journals A Long-Term Ecological Vulnerability Analysis of the Tibetan Region of Natural Conditions and Ecological Protection Programs

2021 ◽  
Vol 13 (19) ◽  
pp. 10598
Author(s):  
Yunxiao Jiang ◽  
Yu Shi ◽  
Rong Li ◽  
Luo Guo
Keyword(s):  
Land Use ◽  
Tibetan Plateau ◽  
Urban Areas ◽  
Principal Component ◽  
Vegetation Coverage ◽  
The Tibetan Plateau ◽  
Sudden Increase ◽  
Landsat Images ◽  
Environment Change ◽  
Ecological Vulnerability

The combined impacts of drastic natural environment change and increasing human interference are making the uncertainty of the Tibetan Plateau’s ecological vulnerability the world’s largest. In this study, an ecological vulnerability index (EVI) of Tibet in the core area of the Tibetan Plateau was assessed using a selected set of ecological, social, and economic indicators and using a spatial principal component analysis (SPCA) to calculate their weights. The data included Landsat images and socio-economic data from 1990 to 2015 in five-year intervals. The results showed that the total EVI remained at a high vulnerability level, with drastic fluctuation from 1990 to 2000 (a peak in 1995, when there was a sudden increase in light vulnerability, which moved to extreme vulnerability in the next period), and minor fluctuations after 2000, gradually increasing from southeast to northwest. In addition, the spatial analysis showed a distinct positive correlation between the EVI and grassland area (0.33), land use degree (0.15), NDVI (0.14), livestock husbandry output, and a negative correlation in terms of desertification area. The artificial afforestation program (AAP) had a positive significant correlation with NDVI (R2 = 0.88), preventing the environment from becoming more vulnerable. The results provide practical information and suggestions for planners to improve the land use degree in urban areas and the vegetation coverage in pastoral regions of the Tibetan Plateau based on the spatial–temporal heterogeneity patterns of the EVI of Tibet.

scholarly journals Urbanization’s Impacts on Ecosystem Health Dynamics in the Beijing-Tianjin-Hebei Region, China

2021 ◽  
Vol 18 (3) ◽  
pp. 918
Author(s):  
Fan Wu ◽  
Xiaoke Wang ◽  
Yufen Ren
Keyword(s):  
Ecological Restoration ◽  
Urban Areas ◽  
Ecosystem Health ◽  
Negative Impact ◽  
Dominant Factor ◽  
Rapid Urbanization ◽  
The North ◽  
Health Dynamics ◽  
High Level ◽  
Bth Region

Accelerated urbanization disturbs ecosystems and influences ecosystem structures and functions. Ecosystem health (ESH) assessments in regions undergoing the rapid urbanization process assist us in understanding how ESH changes and how urbanization specifically affects ESH. We assessed the ESH of Beijing-Tianjin-Hebei (BTH) region, China, including the ecosystem service value (ESV). In this study, we selected nine indicators and applied multiple pieces of software, including ArcGIS10.4, Fragstats4.2 and Geoda1.14 to detect the impacts of urbanization on regional ESH in 1995, 2000, 2005, 2010 and 2015. The results show that ESH in the BTH region increased from 2000 to 2015, especially in the northern parts. The improvements were due to the implementation of key ecological restoration projects protecting and re-establishing the forest in the north. Furthermore, the spatial correlation results indicate that urbanization had a negative impact on ESH in the BTH region, of which the dominant factor was the population density in 1995. The dominant factor was the construction land proportion from 2005 to 2015. We suggest that ecological restoration projects should be continued in northern regions with strong and relatively strong ESH levels to maintain high-level ecosystem health. In addition, more attention should be paid to the ESH level improvement in peri-urban areas.

Urbanization and Changes in Cropping Patterns at Kathmandu Valley

2007 ◽  
Vol 7 ◽  
pp. 113 ◽  
Author(s):  
Raj Man Shrestha
Keyword(s):  
Urban Areas ◽  
Cropping System ◽  
Considerable Change ◽  
Rapid Expansion ◽  
Leafy Vegetables ◽  
Kathmandu Valley ◽  
Rapid Urbanization ◽  
Average Growth ◽  
Cropping Patterns ◽  
Agriculture Land

The increase of population in Kathmandu valley is bringing a considerable change in cropping system. Rapid urbanization and introduction of new agriculture technology have encouraged the valley’s farmers to change their cropping patterns from traditional (low value crops) to new crops (high value crops). According to numerous studies made in Nepal, the change is seen considerably in winter crops than in summer crops and the land under cultivation of green leafy vegetables is increasing rapidly in the urban and semi-urban areas. An average growth of population at 3 % in the valley during the period 1951-2001 has resulted in the rapid expansion of area under urban coverage (24.6 % growth per year from 1984 - 2000) has made agriculture land of Katmandu valley to decline per year by 2.04 % (836.27 ha per year). If this trend of decline in agriculture land in Kathmandu valley continues in future too, it is expected that there will be no agriculture land left over by two and half decades in the valley. The planners should take note of this fact that if fertile land of Katmandu valley is to be preserved for agriculture necessary planning is urgently needed. <i>Nepal Journal of Science and Technology</i> Vol. 7, 2006

scholarly journals Measuring Accessibility Based on Improved Impedance and Attractive Functions Using Taxi Trajectory Data

2020 ◽  
Vol 13 (1) ◽  
pp. 112
Author(s):  
Helai Huang ◽  
Jialing Wu ◽  
Fang Liu ◽  
Yiwei Wang
Keyword(s):  
Waiting Time ◽  
Urban Areas ◽  
Transportation Systems ◽  
Trajectory Data ◽  
Peak Period ◽  
Important Indicator ◽  
Destination Attractiveness ◽  
Urban Accessibility ◽  
Spatio Temporal ◽  
Taxi Trajectory

Accessibility has attracted wide interest from urban planners and transportation engineers. It is an important indicator to support the development of sustainable policies for transportation systems in major events, such as the COVID-19 pandemic. Taxis are a vital travel mode in urban areas that provide door-to-door services for individuals to perform urban activities. This study, with taxi trajectory data, proposes an improved method to evaluate dynamic accessibility depending on traditional location-based measures. A new impedance function is introduced by taking characteristics of the taxi system into account, such as passenger waiting time and the taxi fare rule. An improved attraction function is formulated by considering dynamic availability intensity. Besides, we generate five accessibility scenarios containing different indicators to compare the variation of accessibility. A case study is conducted with the data from Shenzhen, China. The results show that the proposed method found reduced urban accessibility, but with a higher value in southern center areas during the evening peak period due to short passenger waiting time and high destination attractiveness. Each spatio-temporal indicator has an influence on the variation in accessibility.

scholarly journals Where Do I Allocate My Urban Allotment Gardens? Development of a Site Selection Tool for Three Cities in Benin

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 318
Author(s):  
B. G. J. S. Sonneveld ◽  
M. D. Houessou ◽  
G. J. M. van den Boom ◽  
A. Aoudji
Keyword(s):  
Food Insecurity ◽  
Urban Agriculture ◽  
Low Income ◽  
Urban Areas ◽  
Urban Poor ◽  
Site Suitability ◽  
Rapid Urbanization ◽  
Middle Income ◽  
Support Tool ◽  
Allotment Gardens

In the context of rapid urbanization, poorer residents in cities across low- and middle-income countries increasingly experience food and nutrition deficiencies. The United Nations has highlighted urban agriculture (UA) as a viable solution to food insecurity, by empowering the urban poor to produce their own fresh foods and make some profit from surplus production. Despite its potential role in reducing poverty and food insecurity, there appears to be little political will to support urban agriculture. This is seen in unclear political mandates that are sustained by information gaps on selection criteria for UA sites. The research reported here addresses this issue in the form of a decision-making support tool that assesses the suitability of cadastral units and informal plots for allotment gardens in urban and peri-urban areas. The tool was developed and tested for three rapidly expanding cities in Benin, a low-income country in West Africa, based on an ordered logit model that relates a set of 300 expert assessments on site suitability to georeferenced information on biophysical and socio-economic characteristics. Soil, land use, groundwater depth, vicinity to market and women’s safety were significant factors in the assessment. Scaled up across all cadastral units and informal sites, the tool generated detailed baseline maps on site suitability and availability of areas. Its capacity to support policymakers in selecting appropriate sites comes to the fore by reporting changes in site suitability under scenarios of improved soil fertility and enhanced safety for women.

scholarly journals Elevated Risk of Ecological Land and Underlying Factors Associated with Rapid Urbanization and Overprotected Agriculture in Northeast China

2019 ◽  
Vol 11 (22) ◽  
pp. 6203 ◽  
Author(s):  
Shuhan Liu ◽  
Dongyan Wang ◽  
Guoping Lei ◽  
Hong Li ◽  
Wenbo Li
Keyword(s):  
Land Use ◽  
Urban Expansion ◽  
Black Soil ◽  
Residential Area ◽  
Risk Level ◽  
Ecological Value ◽  
Urbanization Process ◽  
Rapid Urbanization ◽  
Important Indicator ◽  
Farming Area

Ecological land with considerable ecological value can be regarded as an important indicator in guaranteeing ecosystem function and sustainable development. Generally, the urbanization process has been considered to be the primary factor affecting ecological land use. However, the influence of agricultural development, particularly in a typical farming area, has rarely been studied. In this paper, we present a method to assess the ecological risk of ecological land (ELER) in a black soil area in northeastern China. Furthermore, the underlying factors were detected using the geographically weighted regression model, which took into account conditions of natural elements, the urbanization process, and grain production conditions. The results indicate that ecological land experienced remarkable changes with an evident loss and decline from 1996–2015. The ELER progressively increased in the concentrated farming area and the western agro-pastoral ecotone, and the ecological land in the eastern forest area was always at a high risk level. According to the regression coefficients, the relationships between influence factors and ELER could be better explained by the variables of elevation, slope, proportion of rural residential area, and ratio of cultivated land area to residential area. To summarize, agricultural occupation and urban expansion were verified as the two main causes of ecological land loss, as well as elevated risks. In light of the current situation, measures such as policy adjustment and ecological restoration should be taken to avoid risk and optimize land use.

scholarly journals Towards eco-social housing in Vietnam: challenges and opportunities

2018 ◽  
Vol 193 ◽  
pp. 01001
Author(s):  
Van Thuong Le ◽  
Tuan Tran ◽  
Truc Truong
Keyword(s):  
Low Income ◽  
Social Housing ◽  
Urban Areas ◽  
Housing Demand ◽  
Living Conditions ◽  
Local Economy ◽  
Rapid Urbanization ◽  
Long Run ◽  
Challenges And Opportunities ◽  
The Government

Since Doi Moi (Reform) policy in 1986, Vietnam has experienced rapid urbanization and economic growth. Urbanization has resulted in increasingly high housing demand in the urban areas but this has largely unmet, especially housing for low-income people. Development of social housing for low-income and under-privileged people in cities has been seen as an urgent and important task of the government to pursue stable social and economic development. Low-income people are most vulnerable to environmental impacts and in need of energy-efficient houses to reduce their cost of living. Eco-social housing is seen as a solution to protect the natural environment as well as to boost local economy, improve living conditions particularly for low income people. Through preliminary assessments of three social buildings at three distinct regions of Vietnam, this paper found that despite many challenges, eco-social housing is a solution to Vietnam's needs in providing houses with adequate living conditions to low-income people while protecting the environment and achieving sustainable eco-social development in the long run.

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.

scholarly journals DOENÇA DE CROHN

2017 ◽  
Vol 4 (2) ◽  
pp. 25
Author(s):  
Nicolas Garcia Papacosta ◽  
Gabriel Martins Nunes ◽  
Renato Jácomo Pacheco ◽  
Macaulay Viturino Cardoso ◽  
Virgílio Ribeiro Guedes
Keyword(s):  
Inflammatory Bowel Disease ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Bowel Disease ◽  
Urban Areas ◽  
Diagnostic Techniques ◽  
Rapid Urbanization ◽  
De Se ◽  
Inflammatory Bowel ◽  
Keywords Crohn's Disease

INTRODUÇÃO: A doença de Crohn é qualificada como uma doença inflamatória intestinal, de caráter crônico, recidivante, transmural e que pode afetar qualquer parte do trato digestivo, desde a boca até o ânus, mas, principalmente, o intestino delgado e o cólon. São de cunho multifatorial, com prevalência e incidência variando de acordo com a genética, meio ambiente, microbiota intestinal e até mesmo um possível agente entérico infeccioso. É uma doença que afeta pessoas de várias idades, sexos e raças, apesar de se verificar maior incidência em jovens do sexo feminino e em regiões urbanas. METODOLOGIA: Trata-se de um artigo de revisão no qual, a partir das palavras “doença de Crohn” e “doença inflamatórias intestinais”, foi realizado busca por periódicos nos bancos de dados: PubMed, Scielo, Portal Periódicos CAPES e Google acadêmico. CONCLUSÃO: A doença de Crohn apresenta uma importante taxa de morbimortalidade no mundo, principalmente em regiões em franca urbanização e industrialização. O diagnóstico é um procedimento extremamente complicado devido a sua clínica inespecífica e pelos vários aspetos em comum com outras patologias. Dessa forma, ainda se faz necessário uma melhor investigação científica na área, com intuito de se desenvolver melhores técnicas diagnosticas e condutas a serem tomadas no seguimento e cura dessa patologia.Palavras-chave: Doença de Crohn, Doença inflamatórias intestinais, Diarreia. ABSTRACT INTRODUCTION: Crohn's disease is described as an inflammatory, chronic, recurrent, transmural inflammatory disease that can affect any part of the digestive tract, from the mouth to the anus, but especially the small intestine and colon. They are multifactorial, with prevalence and incidence varying according to genetics, environment, intestinal microbiota and even a possible infectious enteric agent. It is a disease that affects people of various ages, sexes and races, although there is a greater incidence in young women and in urban areas. METHODOLOGY: This is a review article in which, from the words "Crohn's disease" and "inflammatory bowel disease", a search was made for journals in the databases: PubMed, Scielo, Portal Periódicos CAPES and Google academic. CONCLUSION: Crohn's disease presents an important morbidity and mortality rate in the world, especially in regions where there is rapid urbanization and industrialization. Diagnosis is an extremely complicated procedure due to its nonspecific clinical and various aspects in common with other pathologies. Thus, a better scientific investigation in the area is still necessary, in order to develop better diagnostic techniques and behaviors to be taken in the follow-up and cure of this pathology.                                              Keywords: Crohn's disease, Inflammatory bowel disease, Diarrhea.

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