Characterizing and comparing urban expansion process in central and southern China: intensity and impacts on eco-environment

2012 ◽  
Author(s):  
Zuo Lijun ◽  
Zhao Xiaoli ◽  
Zhang Zengxiang ◽  
Liu Fang ◽  
Xu Jinyong ◽  
...  
Keyword(s):  
Southern China ◽  
Urban Expansion ◽  
Expansion Process

scholarly journals Evaluating the Suitability of Urban Expansion Based on the Logic Minimum Cumulative Resistance Model: A Case Study from Leshan, China

2019 ◽  
Vol 8 (7) ◽  
pp. 291 ◽  
Author(s):  
Haijun Wang ◽  
Peihao Peng ◽  
Xiangdong Kong ◽  
Tingbin Zhang ◽  
Guihua Yi
Keyword(s):  
Urban Development ◽  
Evaluation System ◽  
Urban Expansion ◽  
Ecological Impacts ◽  
Sustainable Urban Development ◽  
Expansion Process ◽  
Mountain Areas ◽  
Resistance Factors ◽  
Ecological Barriers

This paper focuses on the suitability of urban expansion in mountain areas against the background of accelerated urban development. Urbanization is accompanied by conflict and intense transformations of various landscapes, and is accompanied by social, economic, and ecological impacts. Evaluating the suitability of urban expansion (UE) and determining an appropriate scale is vital to solving urban environmental issues and realizing sustainable urban development. In mountain areas, the natural and social environments are different from those in the plains; the former is characterized by fragile ecology and proneness to geological disasters. Therefore, when evaluating the expansion of a mountain city, more factors need to be considered. Moreover, we need to follow the principle of harmony between nature and society according to the characteristics of mountain cities. Thus, when we evaluate the expansion of a mountain city, the key procedure is to establish a scientific evaluation system and explore the relationship between each evaluation factor and the urban expansion process. Taking Leshan (LS), China—a typical mountain city in the upper Yangtze River which has undergone rapid growth—as a case study, the logic minimum cumulative resistance (LMCR) model was applied to evaluate the suitability of UE and to simulate its direction and scale. The results revealed that: An evaluation system of resistance factors (ESRFs) was established according to the principle of natural and social harmony; the logic resistance surface (LRS) scientifically integrated multiple resistance factors based on the ESRF and a logic regression analysis. LRS objectively and effectively reflected the contribution and impact of each resistance factor to urban expansion. We found that landscape, geological hazards and GDP have had a great impact on urban expansion in LS. The expansion space of the mountain city is limited; the area of suitable expansion is only 23.5%, while the area which is unsuitable for expansion is 39.3%. In addition, it was found that setting up ecological barriers is an effective way to control unreasonable urban expansion in mountain cities. There is an obvious scale (grid size) effect in the evaluation of urban expansion in mountain cities; an evaluation of the suitable scale yielded the result of 90 m × 90 m. On this scale, taking the central district as the center, the urban expansion process will extend to the neighboring towns of Mianzhu, Suji, Juzi and Mouzi. Urban expansion should be controlled in terms of scale, especially in mountain cities. The most suitable urban size of LS is 132 km2.This would allow for high connectivity of urban-rural areas with the occupation of relatively few green spaces.

Urban Expansion Process, Pattern, and Land Use Response in an Urban Mining Composited Zone from 1986 to 2013

2016 ◽  
Vol 142 (4) ◽  
pp. 04016014 ◽  
Author(s):  
Xiaoran Zhang ◽  
Zhongke Bai ◽  
Xiang Fan ◽  
Yuanqing Lu ◽  
Yingui Cao ◽  
...  
Keyword(s):  
Land Use ◽  
Urban Expansion ◽  
Expansion Process ◽  
Urban Mining ◽  
Process Pattern

scholarly journals Overwintering, Cold Tolerance and Supercooling Capacity Comparison Between Liriomyza Sativae and L. Trifolii, Two Successively Invaded Leafminers in China

2021 ◽  
Author(s):  
Qikai Zhang ◽  
Shengyong Wu ◽  
Haihong Wang ◽  
Zhonglong Xing ◽  
Zhongren Lei
Keyword(s):  
Cold Tolerance ◽  
Southern China ◽  
Management Strategies ◽  
Northern China ◽  
Competitive Displacement ◽  
Expansion Process ◽  
Supercooling Point ◽  
Liriomyza Sativae ◽  
Horticultural Plants ◽  
Better Than

Abstract Liriomyza sativae Blanchard and Liriomyza trifolii (Burgess) are two highly polyphagous pests that successively invaded China in the 1990s and 2000s, respectively, threatening vegetable and horticultural plants. Competitive displacement of L. sativae by L. trifolii occurred during the expansion process of the latter in southern China. However, whether L. trifolii can expand their range to northern China and, if so, how they compete with L. sativae in northern China remains unclear. Overwintering and cold tolerance capacity largely determine the species distribution range and can affect species displacement through overwintering and phenology. In this study, we compared the overwintering potential, cold tolerance and supercooling point (SCP) between these two leafminer species. Our results showed that L. trifolii can overwinter at higher altitudes than L. sativae. In addition, we found that they can both successfully overwinter in greenhouses in northern China, and the overwintering capacity of L. trifolii was higher than that of L. sativae. Moreover, the extreme low-temperature survival of L. trifolii was significantly higher than that of L. sativae, and the SCP of the former was lower than that of the latter. We thus conclude that the overwintering and cold tolerance capacity of L. trifolii is much better than that of L. sativae. Our findings indicate that L. trifolii has the potential to displace L. sativae and expand its range to northern China. Moreover, our results have important implications for predicting overwinter ranges and developing management strategies for invasive leafminers in China.

scholarly journals Estimating Rainfall Interception of Vegetation Canopy from MODIS Imageries in Southern China

2019 ◽  
Vol 11 (21) ◽  
pp. 2468
Author(s):  
Wu ◽  
Liu ◽  
Sun ◽  
Su ◽  
Wang ◽  
...  
Keyword(s):  
Forest Cover ◽  
Southern China ◽  
Urban Expansion ◽  
Guangdong Province ◽  
Spatiotemporal Variation ◽  
Vegetation Canopy ◽  
Rainfall Interception ◽  
Extreme Rainfall Events ◽  
Area Index ◽  
Basin Scale

The interception of rainfall by vegetation canopies plays an important role in the hydrologic process of ecosystems. Most estimates of canopy rainfall interception in present studies are mainly through field observations at the plot region. However, it is difficult, yet important, to map the regional rainfall interception by vegetation canopy at a larger scale, especially in the southern rainy areas of China. To obtain a better understanding of the spatiotemporal variation of vegetation canopy rainfall interception with regard to the basin scale in this region, we extended a rainfall interception model by combining the observed rainfall data and moderate resolution imaging spectroradiometer leaf area index (MODIS_LAI) data to quantitatively estimate the vegetation canopy rainfall interception rate (CRIR) at small/medium basin scales in Guangdong Province, which is undergoing large changes in vegetation cover due to rapid urban expansion in the area. The results showed that the CRIR in Guangdong declined continuously during 2004–2012, but increased slightly in 2016, and the spatial variability of CRIR showed a diminishing yearly trend. The CRIR also exhibited a distinctive spatial pattern, with a higher rate to the east and west of the mountainous areas and a lower rate in the central mountainous and coastal areas. This pattern was more closely related to the spatial variation of the LAI than that of rainfall due to frequent extreme rainfall events saturating vegetation leaves. Further analysis demonstrated that forest coverage, instead of background climate, has a certain impact on the canopy rainfall interception, especially the proportion of broad-leaved forests in the basin, but more in-depth study is warranted in the future. In conclusion, the results of this study provide insights into the spatiotemporal variation of canopy rainfall interception at the basin scale of the Guangdong Province, and suggest that forest cover should be increased by adjusting the species composition to increase the proportion of native broad-leaved species based on the local condition within the basin. In addition, these results would be helpful in accurately assessing the impacts of forest ecosystems on regional water cycling, and provide scientific and practical implications for water resources management.

scholarly journals Quantifying Urban Vegetation Dynamics from a Process Perspective Using Temporally Dense Landsat Imagery

2021 ◽  
Vol 13 (16) ◽  
pp. 3217
Author(s):  
Wenjuan Yu ◽  
Weiqi Zhou ◽  
Zhaxi Dawa ◽  
Jia Wang ◽  
Yuguo Qian ◽  
...  
Keyword(s):  
Vegetation Dynamics ◽  
Large Scale ◽  
Southern China ◽  
Landsat Imagery ◽  
Urban Expansion ◽  
Recent Change ◽  
Urban Vegetation ◽  
Ecological Protection ◽  
Trends Analysis ◽  
Process Perspective

Urban vegetation can be highly dynamic due to the complexity of different anthropogenic drivers. Quantifying such dynamics is crucially important as it is a prerequisite to understanding its social and ecological consequences. Previous studies have mostly focused on the urban vegetation dynamics through monotonic trends analysis in certain intervals, but not considered the process which provides important insights for urban vegetation management. Here, we developed an approach that integrates trends with dynamic analysis to measure the vegetation dynamics from the process perspective based on the time-series Landsat imagery and applied it in Shenzhen, a coastal megacity in southern China, as an example. Our results indicated that Shenzhen was turning green from 2000–2020, even though a large-scale urban expansion occurred during this period. Approximately half of the city (49.5%) showed consistent trends in greening, most of which were located in the areas within the ecological protection baseline. We also found that 35.3% of the Shenzhen city experienced at least a one-time change in urban greenness that was mostly caused by changes in land cover types (e.g., vegetation to developed land). Interestingly, 61.5% of these lands showed trends in greening in the recent change period and most of them were distributed in build-up areas. Our approach that integrates trends analysis and dynamic process reveals information that cannot be discovered by monotonic trends analysis alone, and such information can provide insights for urban vegetation planning and management.

scholarly journals URBAN EXPANSION MODELING APPROACH BASED ON MULTI-AGENT SYSTEM AND CELLULAR AUTOMATA

2018 ◽  
Vol XLII-3 ◽  
pp. 2219-2223
Author(s):  
Y. N. Zeng ◽  
M. M. Yu ◽  
S. N. Li
Keyword(s):  
Change Process ◽  
Urban Expansion ◽  
Urban Land ◽  
Kappa Coefficient ◽  
Multi Agent System ◽  
Impervious Surfaces ◽  
Expansion Process ◽  
Multi Agent ◽  
Expansion Model

Urban expansion is a land-use change process that transforms non-urban land into urban land. This process results in the loss of natural vegetation and increase in impervious surfaces. Urban expansion also alters the hydrologic cycling, atmospheric circulation, and nutrient cycling processes and generates enormous environmental and social impacts. Urban expansion monitoring and modeling are crucial to understanding urban expansion process, mechanism, and its environmental impacts, and predicting urban expansion in future scenarios. Therefore, it is important to study urban expansion monitoring and modeling approaches. We proposed to simulate urban expansion by combining CA and MAS model. The proposed urban expansion model based on MSA and CA was applied to a case study area of Changsha-Zhuzhou-Xiangtan urban agglomeration, China. The results show that this model can capture urban expansion with good adaptability. The Kappa coefficient of the simulation results is 0.75, which indicated that the combination of MAS and CA offered the better simulation result.

scholarly journals Examining Small-Town Growth and Expansion in Peri-urban Areas of Small Cities: Evidence from Peripheries of Three Small Cities in Central Java

2021 ◽  
Vol 32 (3) ◽  
pp. 216-232
Author(s):  
Fadjar Hari Mardiansjah ◽  
Agung Sugiri ◽  
Samsul Ma'rif
Keyword(s):  
Urban Areas ◽  
Growth And Development ◽  
Small Town ◽  
Urban Expansion ◽  
Small Towns ◽  
Policy Implications ◽  
Expansion Process ◽  
Small Cities ◽  
Central Java ◽  
Surrounding Areas

Urbanization in small and medium-sized cities in Java is marked by an urban expansion process to the surrounding areas, forming the growing small towns in their peripheries. Using the case of the extended urban areas of Tegal, Pekalongan and Magelang in Central Java, this study examined small-town growth and development in peri-urban areas of small and medium cities. It first looked at the growth of small towns in the peri-urban areas of these small cities and then identified various factors and mechanisms that contribute to the formation, growth and expansion of small towns. The study further looked into the challenges and implications of the trend toward policies for managing such processes more sustainably. The growth of urbanized villages in some kabupatens (non-urban districts or regencies) surrounding these small cities, as documented by the national statistical board  from 1990 to 2017, was used as the basis for analyzing these factors. This paper concludes with a discussion on the challenges and policy implications for growing small towns. The findings of this study can be useful for formulating a better approach to managing urbanization processes in the future.   Abstrak. Urbanisasi kota-kota kecil dan menengah di Jawa ditandai dengan proses perluasan kota ke wilayah sekitarnya, membentuk kota-kota kecil yang berkembang di pinggirannya. Dengan menggunakan kasus perluasan wilayah Tegal, Pekalongan dan Magelang di Jawa Tengah, penelitian ini mengkaji pertumbuhan dan perkembangan kota kecil di wilayah pinggiran kota kecil dan menengah. Ini pertama-tama melihat pertumbuhan kota-kota kecil di daerah pinggiran kota-kota kecil ini dan kemudian mengidentifikasi berbagai faktor dan mekanisme yang berkontribusi pada pembentukan, pertumbuhan, dan perluasan kota-kota kecil. Studi ini lebih jauh melihat tantangan dan implikasi dari tren terhadap kebijakan untuk mengelola proses tersebut secara lebih berkelanjutan. Pertumbuhan desa urban di beberapa kabupaten (kabupaten atau kabupaten non-urban) di sekitar kota-kota kecil tersebut, sebagaimana didokumentasikan oleh BPS (Badan Pusat Statistik) dari tahun 1990 hingga 2017, digunakan sebagai dasar untuk menganalisis faktor-faktor tersebut. Makalah ini diakhiri dengan diskusi tentang tantangan dan implikasi kebijakan untuk pertumbuhan kota-kota kecil. Temuan studi ini dapat berguna untuk merumuskan pendekatan yang lebih baik untuk mengelola proses urbanisasi di masa depan.   Kata kunci. Jawa Tengah, kota kecil, urbanisasi, ekspansi kota.

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