According to a report published by the Ministry of Industry and Information Technology(MIIT)recently,in 2019,the Chinese copper industry witnessed smooth running,year-on-year growth of benefits,declined price,continuo...According to a report published by the Ministry of Industry and Information Technology(MIIT)recently,in 2019,the Chinese copper industry witnessed smooth running,year-on-year growth of benefits,declined price,continuously weakened downstream consumption,and over capacity risk that can’t be ignored.展开更多
Urban sprawl is a critical challenge in the urban development trajectory of developing countries,necessitating precise measurement,trend projection,and strategic management to achieve sustainable urban growth.This stu...Urban sprawl is a critical challenge in the urban development trajectory of developing countries,necessitating precise measurement,trend projection,and strategic management to achieve sustainable urban growth.This study focuses on the Yangtze River Economic Belt(YREB)as a case region and introduces a comprehensive evaluation framework that incorporates multidimensional factors and addresses the scale effects of urban sprawl.We emphasize the value of a systematic geographical approach by quantifying urban sprawl through simulated scenarios and analyzing its driving factors.We constructed an innovative urban sprawl index(USI)to assess the degree of sprawl within the YREB.This assessment integrates two geographic models with an artificial neural network algorithm,enabling simulation of urban sprawl trends under two future scenarios for 2035.Additionally,two analytical methods were employed to identify the key driving mechanisms of urban sprawl in the region.Findings indicate a strong correlation between urban scale and the extent of urban sprawl:larger urban areas exhibit more pronounced sprawl,with agglomeration and morphological transformations identified as primary contributors to urban sprawl.The study further reveals an intricate association between urban sprawl and the compactness of urban internal structures.While both development scenarios offer distinct advantages,the Coordinated Development Scenario is projected to foster a more balanced urban expansion.The robustness of the evaluation framework was enhanced through simulation and an in-depth analysis of internal mechanisms,bolstering confidence in its applicability.We advocate for the adoption and continued refinement of this framework as a tool for promoting balanced urban growth.The strategic recommendations provided herein are vital for mitigating multi-scale urban sprawl,advancing economic development,and improving residents’quality of life across cities in the YREB.展开更多
Urbanization in small-and medium-sized cities has often been overlooked in urban studies.Research on urbanization has predominantly focused on large metropolitan cities;however,urbanization in small-and medium-sized c...Urbanization in small-and medium-sized cities has often been overlooked in urban studies.Research on urbanization has predominantly focused on large metropolitan cities;however,urbanization in small-and medium-sized cities also contributes to the acceleration of urban sprawl.Urban growth boundary(UGB)is an ecological approach designed to limit urban development.This study aimedto analyze environmental protection priority zonesby combining ecological quality and sensitivity indices to identify the areas suitable for UGB implementation.Tegal City and its surrounding areas(including Tegal and Brebes regencies)of Indonesia were selected as the study area.The ecological quality index was calculated using the normalized difference vegetation index,humidity index,land surface temperature,and normalized difference bare soil index.These indices were subsequently subjected to principal component analysis(PCA)to extract orthogonal factors,which were summed to derive the final index value.In parallel,we mapped and evaluated ecological sensitivity based on spatial planning policies and regulations.The results revealed that ecological quality in Tegal and Brebes regencies was predominantly categorized as good and very good ecological quality,whereas TegalCity exhibited moderate and poor ecological quality.Additionally,over 45.00%of the area in Tegal and Brebes regencies demonstrated very high ecological sensitivity.Consequently,more than 50.00%of the area in Tegal and Brebes regencies,along with 27.00%of Tegal City,were classified as ecological constraint zone,making them potential regionsfor UGB development.The UGB is expected to curtail urban expansion,promote compact city planning,and preserve ecosystem services to achieve urban sustainability.This study implies that planningsmall-and medium-sized cities is important to prevent urban sprawl and maintain environmental health.Designing UGB to limit urban expansion should be enhanced by better knowledge about its ecological functions in supporting urban sustainability.展开更多
The background and connotations of smart growth theories of America were introduced first,spatial expansion features of Nanjing City were summarized as the following 3 points:population growth,expansion of urban space...The background and connotations of smart growth theories of America were introduced first,spatial expansion features of Nanjing City were summarized as the following 3 points:population growth,expansion of urban spaces and industrial expansion.And then problems emerged in the spatial expansion were pointed out as:A."Sprawl" in the urban development;B.Improper internal spatial structure of the city;C.Destructed historical and cultural context of the city.Smart growth theories were applied in this study to analyze potential problems in the spatial expansion of Nanjing,corresponding countermeasures were given as:defining proper growth boundaries,restricting total growth volume,saving land;strictly controlling growth intensity,fully utilizing resources,intensively using land;scientifically evaluating growth benefits,promoting recycling of resources,and realizing sustainable growth.By learning from overseas smart growth theories,the authors hoped to provide useful references for the overall land use planning and urban planning of Nanjing City.展开更多
Green space is a sort of land use types with certain ecological service functions.Taking TM/ETM+ images and MODIS-NDVI images in 1992,1999 and 2005 as the basic data,the quantitative changes and quality changes of gre...Green space is a sort of land use types with certain ecological service functions.Taking TM/ETM+ images and MODIS-NDVI images in 1992,1999 and 2005 as the basic data,the quantitative changes and quality changes of green space in Beijing in recent years were studied by interpretation and classification.The relationship between green space and urban construction was studied.Through the field investigation and data analysis,the driving forces of green space changes were studied and corresponding suggestions were put forward.展开更多
Landsat Thematic Mapper （TM） and Enhanced Thematic Mapper Plus （ETM＋） images in 1985, 1986, 1993, 1994 and 2001 were used to quantify the land use and land cover changes （LUCC） in the Zhejiang coastal region wi...Landsat Thematic Mapper （TM） and Enhanced Thematic Mapper Plus （ETM＋） images in 1985, 1986, 1993, 1994 and 2001 were used to quantify the land use and land cover changes （LUCC） in the Zhejiang coastal region with a stratified unsupervised classification technique in conjunction with visual interpretation and to attempt an identification of the socioeconomic driving forces. In level I an overall accurate classification was achieved using a modified Anderson＇s Ⅰ/Ⅱ/Ⅲ-level classification scheme. The overall accuracy of the land use classification at Anderson level Ⅰ were 89.7% （1985）, 91.6% （1993）, and 90.4% （2001）. The most rapid land use change was a dramatic increase in urban or built-up areas, which quadrupled from 1985 to 2001. Over 90% of this newly expanded built-up area was originally paddy fields or other croplands. In different parts of the Zhejiang coastal region, urban land expansion was spatially uneven. Temporally, land use development did not stabilized, and the two study periods of time （1985-1993 and 1993-2001） had different transition styles. Socioeconomic factors, such as gross domestic product, total population, and financial expenditure, were all highly correlated with the expansion of urban or built-up areas. Based on the degree of urban sprawl and socioeconomic factors, cities and towns were further divided into six subgroups, which may help decision makers improve land use for the region.展开更多
Concerning about the rapid urban growth in recent China, this study takes Beijing as a case and puts forward that urban sprawl can be measured from spatial configuration, urban growth efficiency and external impacts, ...Concerning about the rapid urban growth in recent China, this study takes Beijing as a case and puts forward that urban sprawl can be measured from spatial configuration, urban growth efficiency and external impacts, and then develops a geo-spatial indices system for measuring sprawl, a total of 13 indicators. In order to calculate these indices, different sources data are selected, including land use maps, former land use planning, land price and floor-area-ratio samples, digitized map of the highways and city centers, population and GDP statistical data, etc. Various GIS spatial analysis methods are used to spatialize these indices into 100mx100m cells. Besides, an integrated urban sprawl index is calculated by weight sum of these 13 indices. The application result indicates that geo-spatial indices system can capture most of the typical features and interior differentia of urban sprawl. Construction land in Beijing has kept fast growing with large amount, low efficiency and disordered spatial configuration, indicating a typical sprawling tendency. The following specific sprawl features are identified by each indicator： （1） typical spatial configuration of sprawling： obvious fragmentation and irregularity of landscape due to unsuccessful enforcement of land use planning, unadvisable pattern of typical discontinuous development, strip development and leapfrog development; （2） low efficiency of sprawl： low development density, low population density and economic output in newly developed area; and （3） negative impacts on agriculture, environment and city life. According to the integrated sprawl index, the sprawling amount in the northern part is larger than that in the southern, but the sprawling extent is in converse case; most sprawling area include the marginal area of the near suburbs and the area between highways, etc. Four sprawling patterns are identified： randomly expansion at urban fringe, strip development along or between highways, scattered development of industrial land, leapfrog development of urban residence and industrial area.展开更多
The Yangtze delta area is among the fastest developing areas in China. Here there are mega-cities like Shanghai, Nanjing and the attached urban areas of different sizes including those along the lower reaches of the Y...The Yangtze delta area is among the fastest developing areas in China. Here there are mega-cities like Shanghai, Nanjing and the attached urban areas of different sizes including those along the lower reaches of the Yangtze River from Shanghai up to Nanjing as well as their satellite cities and towns, forming one of the most densely distributed urban areas in China. This is a case study done in Suzhou city at the center of the Yangtze delta to reflect the impact of urban sprawl on soil resources using satellite images and digital soil databases. The extent of the developed land in the studied area and the impact of development on soil resources at 1:100,000 scale are estimated and the soil types impacted most by urbanization development are determined through overlaying the soil map on the satellite images (Landsat-7) of the studied area at different times (1984, 1995, 2000 and 2003). The methodology for this study consists of analyzing data resulting from using a geographic information system (GIS) to combine urban land use maps of different times derived from satellite images with data on soil characteristics contained in the established soil databases by which some results come into being to present the fast expanding trend of urbanization in the Yangtze delta area, the urban spread and the soils occupied by the urbanization process, and also the quality of the occupied soils.展开更多
Urban expansion brought by the rapid progress of urbanization has caused many problems in China. It is a significant issue to evaluate the extent of urban expansion and to make appropriate controls over the sprawl of ...Urban expansion brought by the rapid progress of urbanization has caused many problems in China. It is a significant issue to evaluate the extent of urban expansion and to make appropriate controls over the sprawl of urban areas. With a comparative study of international experiences, this article analyzed the mechanism and consequences of urban expansion, reviewed the typical planning and financial policies adopted by other countries for controlling urban sprawl, and discussed the suitable densities of urban areas. The analysis results suggested that Chinese cities have no better choice but compact urban forms. To achieve the goal of compact development, intensive use of public transportation and high proportion of collective houses should be encouraged, and 60–100 m2 per capita is recommended as the reasonable range of urban density in large cities.展开更多
Urban sprawl is driven by a myriad of factors, the predominant one of which is the development of residential land. Selecting part of Jinan City for a case study, we use the landscape metric of percent of landscape (P...Urban sprawl is driven by a myriad of factors, the predominant one of which is the development of residential land. Selecting part of Jinan City for a case study, we use the landscape metric of percent of landscape (PLAND) to capture residential land growth and density changes in 1989, 1996 and 2004 to illuminate the dynamic process of residential land development. The results indicate that the moving window method and the landscape metrics method are efficient ways to describe residential land density. The residential land showed the greatest change among the built-up land with 1995.68 ha from 1989 to 2004, which is mainly transformed from agriculture land and green space. The urban center area of study area is primarily covered with medium density residential land, and surrounded by high density residential land. The development pattern of residential land exhibited both fill-in (new growth occurs through infilling the free spaces within the developed area) and sprawl processes, influenced by a series of factors, such as urban development policy, conservation of springs, recreational and aesthetic amenities. The findings of the study will help to guide urban planning with a focus on the management and protection of the environment and resources.展开更多
Current global urbanisation processes are leading to new forms of massive urban constellations. The conceptualisations and classifications of these, however, are often ambiguous, overlap or lag behind in scientific li...Current global urbanisation processes are leading to new forms of massive urban constellations. The conceptualisations and classifications of these, however, are often ambiguous, overlap or lag behind in scientific literature. This article examines whether there is a common denominator to define and delimitate–and ultimately map–these new dimensions of cityscapes. In an extensive literature review we analysed and juxtaposed some of the most common concepts such as megacity, megaregion or megalopolis. We observed that many concepts are abstract or unspecific, and for those concepts for which physical parameters exist, the parameters are neither properly defined nor used in standardised ways. While understandably concepts originate from various disciplines, the authors identify a need for more precise definition and use of parameters. We conclude that often, spatial patterns of large urban areas resemble each other considerably but the definitions vary so widely that these differences may surpass any inconsistencies in the spatial delimitation process. In other words, today we have tools such as earth observation data and Geographic Information Systems to parameterise if clear definitions are provided. This appears not to be the case. The limiting factor when delineating large urban areas seems to be a commonly agreed ontology.展开更多
With rapid economic development,the size of urban land in China is expanding dramatically.The Urban Growth Boundary(UGB)is an expandable spatial boundary for urban construction in a certain period in order to control ...With rapid economic development,the size of urban land in China is expanding dramatically.The Urban Growth Boundary(UGB)is an expandable spatial boundary for urban construction in a certain period in order to control the urban sprawl.Reasonable delineation of UGB can inhibit the disorderly spread of urban space and guide the normal development of the city.It is of practical significance for the construction of green urban space.The study utilizes GIS technology to establish a land construction suitability evaluation system for Nankang city,which is experiencing rapid urban expansion,and outlines the preliminary UGB under the future land use simulation(FLUS)model.At the same time,considering the coupled coordination of"Production-Living-Ecological Space",and based on the suitability evaluation,we revised the preliminary UGB by combining the advantages of the patch-generating land use simulation(PLUS)model and the convex hull model to delineate the final UGB.The results show that:1)the comprehensive score of the evaluation of the suitability of the construction of land from high to low shows the distribution of the center of the city to the surrounding circle type spread,the center of the city has the highest suitability score.The results of convex hull model show that the urban expansion type of Nankang is epitaxial.In the future,the urban expansion will mainly occur in the northern part of the city.The PLUS model predicts an increase of 3359.97 hm^(2)of construction land in Nankang by 2035,of which 2022.97 hm^(2)is urban construction land.2)The FLUS model has a prediction accuracy of 86.3%and delineates a preliminary UGB area of 9215.07 hm^(2).3)We used the results of the construction suitability evaluation,PLUS model simulation results,and convex hull model predictions to revise the originally delineated UGB.The final delineated UGB area is 8895.67 hm^(2)and it is capable of meeting the future development of the study area.The results of the delineation can promote sustainable urban development,and the delineation methodology can provide a reference basis for the preparation of territorial spatial planning.展开更多
Urban land density is an important factor to understand how cities expand.An“Inverse S-shape Rule”was implemented for the first time to analyze urban land density in Northeastern Thailand using the four cities Khon ...Urban land density is an important factor to understand how cities expand.An“Inverse S-shape Rule”was implemented for the first time to analyze urban land density in Northeastern Thailand using the four cities Khon Kaen,Udon Thani,Nakhon Phanom,and Nong Khai as study sites.Land density function was tested using different data classification techniques from previous studies.Each city was investigated over two different time periods between 2002 and 2015.Declining pattern characteristics of metropolitan area density outward from city centers can be quantified by fitting the parameters to urban land density functions.An inverse S-shape function was identified as the best data fit.The four selected cities showed conventional density variation for decline in urban land area from city centers to outlying areas.Overall trend indicated that cities became more compact over time since the density differences between the urban core and urban fringe were greater with increasing infilling growth within the urban boundary.All four cities increased in size over time;however,the increasing amount of built-up land in the surrounding rural areas did not follow the same trend in each case.Some functional parameters required careful interpretation because of the linear shape of the city as in the case of Nakhon Phanom.Using highly detailed urban data resulted in lower densities of urban areas compared to the conventional pixel-based classification,and this affected the overall shape of the inverse S-shape function.The fitted parameters and their changing trends indicated that the urban land density function was useful for understanding urban form and urban sprawl in Thailand.Results can be used to develop a specific framework for other cities with similar attributes in the future.展开更多
Given that many cities in Saudi Arabia have been observing rapid urbanization since the 1990s,scarce studies on the spatial pattern of urban expansion in Saudi Arabia have been conducted.Therefore,the present study in...Given that many cities in Saudi Arabia have been observing rapid urbanization since the 1990s,scarce studies on the spatial pattern of urban expansion in Saudi Arabia have been conducted.Therefore,the present study investigates the evidence of land use and land cover(LULC)dynamics and urban sprawl in Abha City of Saudi Arabia,which has been experiencing rapid urbanization,from the past to the future using novel and sophisticated methods.The SVM classifier was used in this study to classify the LULC maps for 1990,2000,and 2018.The LULC dynamics between 1990–2000,2000–2018,and 1990–2018 have been analyzed using delta()change and the Markovian transitional probability matrix.Urban sprawl or urban expansion was modeled using two approaches,such as landscape fragmentation and presence frequency for the first time.The future LULC map for 2028 was predicted using the artificial neural network-cellular automata model(ANN-CA).Future LULC was analyzed using landscape fragmentation and frequency approaches.The results of LULC maps showed that urban areas increased by 334.4%between 1990 and 2018.The Delta change rate showed that 16.34%in urban areas has increased since 1990.While,the transitional probability matrix between 1990 and 2018 reported that the built-up area is the largest stable LULC,having an 83.6%transitional probability value.While 17.9%,21.8%,12.4%,and 10.5%of agricultural land,scrubland,exposed rocks,and water bodies were transformed into built-up areas.Urban sprawl models showed that 139 km^(2)of new urban areas had been set up in 2018,49 and 69 km^(2)in 1990 and 2000.Furthermore,in 2018,more than 200%of urban areas were stabilized or became core urban areas.The future LULC map(2028)showed that the built-up area would be 343.72 km^(2),followed by scrubland(342.98 km^(2))and sparse vegetation(89.96 km^(2)).The new urban area in 2028 would be 169 km^(2).The authorities and planners should focus more on the sustainable development of urban areas;otherwise,it would harm the natural and urban environment.展开更多
Several factors may contribute to on-going challenges for spatial planning and policy in megacities such as Rome, including rapid population shifts, poorly organized areas, and lack of data through which monitoring ur...Several factors may contribute to on-going challenges for spatial planning and policy in megacities such as Rome, including rapid population shifts, poorly organized areas, and lack of data through which monitoring urban growth and land use change. This research was conducted to examine past and current effects of the urbanization process, occurred over the large Roman urban system, on the basis of multi-source and multi-temporal optical remote sensing (RS) data, collected between 1990 and 2013. These changes were then validated via Geographic Information System (GIS) techniques, in a particular procedure applied to urban land/agricultural transformations. The proposed approach, based on geo-statistical methods, was used to calculate the index of innovative space (AP Index), useful for the monitoring of the urban sprawl phenomenon. Strong evidence of urban expansion over the north-eastern quarter of the city, accompanied by environmental degradation and loss of biodiversity, is provided. Urban infill developments are expected to emerge in the south-eastern areas too, and these might increase urban pressure as well. In conclusion, RS and GIS technologies together with ancillary data can be used to assist decision makers in preparing future plans to find out appropriate solutions to urbanization encroachment.展开更多
Taking Harare metropolitan province in Zimbabwe as an example, we classified Landsat imagery (1984, 2002, 2008 and 2013) by using support vector machines (SVMs) and analyzed built-up and non-built-up changes. The over...Taking Harare metropolitan province in Zimbabwe as an example, we classified Landsat imagery (1984, 2002, 2008 and 2013) by using support vector machines (SVMs) and analyzed built-up and non-built-up changes. The overall classification accuracy for the four dates ranged from 89% to 95%, while the overall kappa varied from 86% to 93%. The results demonstrate that SVMs provide a cost-effective technique for mapping urban land use/cover by using mediumresolution satellite images such as Landsat. Based on land use/cover maps for 1984, 2002, 2008 and 2013, along with change analyses, built-up areas increased from 12.6% to 36.3% of the total land area, while non-built-up cover decreased from 87.3% to 63.4% between 1984 and 2013. The results revealed an urban growth process characterized by infill, extension and leapfrog developments. Given the dearth of spatial urban growth information in Harare metropolitan province, the land use/cover maps are valuable products that provide a synoptic view of built-up and non-built-up areas. Therefore, the land use/cover change maps could potentially assist decision-makers with up-to-date built-up and non-built-up information in order to guide strategic implementation of sustainable urban land use planning in Harare metropolitan province.展开更多
To shed light on the general patterns and trends in urban sprawl research,and to provide reference for future study,bibliometric analysis and refined analysis are conducted for publications in this area from 1991 to 2...To shed light on the general patterns and trends in urban sprawl research,and to provide reference for future study,bibliometric analysis and refined analysis are conducted for publications in this area from 1991 to 2011.The general publication output,the global geographical distribution of the authors,the funding and institutions involved,the research areas,and the source titles are analyzed and discussed.Scholars in the United States and China have produced most of the documents in urban sprawl and these two countries are also the largest contributors in terms of funding and institutions.′Environmental Sciences&Ecology′,′Urban Studies′,and′Geography′are the most common research areas,and the journal titled Urban Studies has contributed the most articles.Furthermore,the refined analyses on the 500 top-cited and most relevant publications have revealed that research on urban sprawl is closely associated with the categories of′Urban form and development′,′Land use/land development′and′environment/ecology/biology′.Conclusions are made with respect to the basic paradigm of research on urban sprawl.The multi-disciplinary research into urban sprawl are expected to be more diversified and integrated.展开更多
Inspired by the cockroach’s use of a pitch-roll mode traverses through narrow obstacles,we improve the RHex-style robot by adding two sprawl joints to adjust the body posture,and propose a novel pitch-roll approach t...Inspired by the cockroach’s use of a pitch-roll mode traverses through narrow obstacles,we improve the RHex-style robot by adding two sprawl joints to adjust the body posture,and propose a novel pitch-roll approach that enables an RHex-style robot to traverse through two cylindrical obstacles with a spacing of 90 mm,about 54%body width.First,the robot can pitch up against the obstacle on the one side by the cooperation of its rear and middle legs.Then,the robot rotates one side rear leg to kick the ground fast,meanwhile the sprawl joint on the other side rotates inward to make the robot roll and fall forward.Finally,the robot can rotate the legs on the ground to move the body forward until it crosses the obstacles.In this article,both cylinder and rectangular columns are considered as the narrow obstacles for traversing.The experiments are demonstrated by using the proposed approach,and the results show that the robot can smoothly traverse through different narrow spaces.展开更多
Urban sprawl has been a prevailing phenomenon in developing countries like China,potentially resulting in significant carbon dioxide(CO_(2))emissions from the transport sector.However,the impact of urban sprawl on tra...Urban sprawl has been a prevailing phenomenon in developing countries like China,potentially resulting in significant carbon dioxide(CO_(2))emissions from the transport sector.However,the impact of urban sprawl on transport CO_(2) emissions(TCEs)is still not fully understood and remains somewhat rudimentary.To systematically investigate how urban sprawl influences TCEs,we employ panel regression and panel threshold regression for 274 Chinese cities(2005-2020),and obtain some new findings.Our results affirm that the degree of urban sprawl is positively associated with TCEs,and this holds true in different groups of city size and geographical region,while significant heterogeneity is observed in terms of such impact.Interestingly,we find urban sprawl nonlinearly impacts TCEs—with an equal increase in urban sprawl degree,TCEs are even lower in cities with larger population size and better economic condition,particularly in East China.Furthermore,the low-carbon city pilot policy shows potential in mitigating sprawl's impact on TCEs.Drawing on our findings,we argue that to achieve the target of TCEs reduction in China by curbing urban sprawl,more priority should be placed on relatively small,less developed,and geographically inferior cities for cost-efficiency reasons when formulating future urban development strategies.展开更多
Today, climate change imposes enormous challenges on a global scale. The interactions of the balances between the need for development, population growth, massive urbanization generate a negative impact on the presenc...Today, climate change imposes enormous challenges on a global scale. The interactions of the balances between the need for development, population growth, massive urbanization generate a negative impact on the presence of these climate changes. One of the direct consequences of these changes is the phenomenon of flash floods, a phenomenon that hit the city of Jeddah (city located in west of Saudi Arabia) twice, one in 2009 and the other in 2011, causing significant human and material damage. Floods are considered as a direct result of the combination of extreme weather and hydrological phenomena;in most cases, the magnitude of these floods is magnified by anthropogenic factors, which increases the risk. According to the risk triangle, risk is defined as a probabilistic function that depends on three essential elements: exposure, vulnerability and hazard. If any of these three elements undergo growth the risk also does so and vice versa. Exposure and vulnerability will depend on the presence of human activities in the study area. This study is conducted on the Wadi Goss watershed as it was one of the most violent basins during the 2009 and 2011 floods. Indeed, we present in this study the extent of the urban extension in the Wadi Goss watershed, since 1984 to days and this by the using Landsat images. Given the nature of the study area, we present a method based on the calculation of various indices followed by a classification operation in order to define the urbanized zones inside the Wadi Goss watershed and then estimate the urban sprawl inside the watershed. We also present in this paper, the characteristics of the watershed as well as the evolution of the urbanized areas exposed to the phenomenon of floods and their contribution to the changes of the hydrological behavior of the basin, and to increase the evolution of the risk of the floods. We have shown through this study that the urban footprint has increased from 90 hectares in 1985 to 850 hectares in 2015. This urban footprint represents 12% of the total area of the watershed. Most of the urban evolution was operated on the wadi area with a concentration in the western part of the basin and especially at its outlet.展开更多
文摘According to a report published by the Ministry of Industry and Information Technology(MIIT)recently,in 2019,the Chinese copper industry witnessed smooth running,year-on-year growth of benefits,declined price,continuously weakened downstream consumption,and over capacity risk that can’t be ignored.
基金supported by the National Natural Science Foundation of China(Grant No.U24A20580)National Natural Science Foundation of China(Grant No.42171298)+1 种基金Natural Science Foundation of Chongqing,China(Grant No.CSTB2023NSCQLZX0009)Philosophy and Social Science Major Project of Chongqing Municipal Education Commission(Grant No.24SKZDZX04).
文摘Urban sprawl is a critical challenge in the urban development trajectory of developing countries,necessitating precise measurement,trend projection,and strategic management to achieve sustainable urban growth.This study focuses on the Yangtze River Economic Belt(YREB)as a case region and introduces a comprehensive evaluation framework that incorporates multidimensional factors and addresses the scale effects of urban sprawl.We emphasize the value of a systematic geographical approach by quantifying urban sprawl through simulated scenarios and analyzing its driving factors.We constructed an innovative urban sprawl index(USI)to assess the degree of sprawl within the YREB.This assessment integrates two geographic models with an artificial neural network algorithm,enabling simulation of urban sprawl trends under two future scenarios for 2035.Additionally,two analytical methods were employed to identify the key driving mechanisms of urban sprawl in the region.Findings indicate a strong correlation between urban scale and the extent of urban sprawl:larger urban areas exhibit more pronounced sprawl,with agglomeration and morphological transformations identified as primary contributors to urban sprawl.The study further reveals an intricate association between urban sprawl and the compactness of urban internal structures.While both development scenarios offer distinct advantages,the Coordinated Development Scenario is projected to foster a more balanced urban expansion.The robustness of the evaluation framework was enhanced through simulation and an in-depth analysis of internal mechanisms,bolstering confidence in its applicability.We advocate for the adoption and continued refinement of this framework as a tool for promoting balanced urban growth.The strategic recommendations provided herein are vital for mitigating multi-scale urban sprawl,advancing economic development,and improving residents’quality of life across cities in the YREB.
基金funded by the Directorate of Research and Community Service, Ministry of Education, Culture, Research, and Technology, Indonesia (027/E5/PG.02.00.PL/2024)Bogor Agricultural University for their invaluable support and resources that made this research possibleDirectorate of Research and Community Service, Ministry of Education, Culture, Research, and Technology, Indonesia, for their financial and administrative support
文摘Urbanization in small-and medium-sized cities has often been overlooked in urban studies.Research on urbanization has predominantly focused on large metropolitan cities;however,urbanization in small-and medium-sized cities also contributes to the acceleration of urban sprawl.Urban growth boundary(UGB)is an ecological approach designed to limit urban development.This study aimedto analyze environmental protection priority zonesby combining ecological quality and sensitivity indices to identify the areas suitable for UGB implementation.Tegal City and its surrounding areas(including Tegal and Brebes regencies)of Indonesia were selected as the study area.The ecological quality index was calculated using the normalized difference vegetation index,humidity index,land surface temperature,and normalized difference bare soil index.These indices were subsequently subjected to principal component analysis(PCA)to extract orthogonal factors,which were summed to derive the final index value.In parallel,we mapped and evaluated ecological sensitivity based on spatial planning policies and regulations.The results revealed that ecological quality in Tegal and Brebes regencies was predominantly categorized as good and very good ecological quality,whereas TegalCity exhibited moderate and poor ecological quality.Additionally,over 45.00%of the area in Tegal and Brebes regencies demonstrated very high ecological sensitivity.Consequently,more than 50.00%of the area in Tegal and Brebes regencies,along with 27.00%of Tegal City,were classified as ecological constraint zone,making them potential regionsfor UGB development.The UGB is expected to curtail urban expansion,promote compact city planning,and preserve ecosystem services to achieve urban sustainability.This study implies that planningsmall-and medium-sized cities is important to prevent urban sprawl and maintain environmental health.Designing UGB to limit urban expansion should be enhanced by better knowledge about its ecological functions in supporting urban sustainability.
文摘The background and connotations of smart growth theories of America were introduced first,spatial expansion features of Nanjing City were summarized as the following 3 points:population growth,expansion of urban spaces and industrial expansion.And then problems emerged in the spatial expansion were pointed out as:A."Sprawl" in the urban development;B.Improper internal spatial structure of the city;C.Destructed historical and cultural context of the city.Smart growth theories were applied in this study to analyze potential problems in the spatial expansion of Nanjing,corresponding countermeasures were given as:defining proper growth boundaries,restricting total growth volume,saving land;strictly controlling growth intensity,fully utilizing resources,intensively using land;scientifically evaluating growth benefits,promoting recycling of resources,and realizing sustainable growth.By learning from overseas smart growth theories,the authors hoped to provide useful references for the overall land use planning and urban planning of Nanjing City.
文摘Green space is a sort of land use types with certain ecological service functions.Taking TM/ETM+ images and MODIS-NDVI images in 1992,1999 and 2005 as the basic data,the quantitative changes and quality changes of green space in Beijing in recent years were studied by interpretation and classification.The relationship between green space and urban construction was studied.Through the field investigation and data analysis,the driving forces of green space changes were studied and corresponding suggestions were put forward.
文摘Landsat Thematic Mapper （TM） and Enhanced Thematic Mapper Plus （ETM＋） images in 1985, 1986, 1993, 1994 and 2001 were used to quantify the land use and land cover changes （LUCC） in the Zhejiang coastal region with a stratified unsupervised classification technique in conjunction with visual interpretation and to attempt an identification of the socioeconomic driving forces. In level I an overall accurate classification was achieved using a modified Anderson＇s Ⅰ/Ⅱ/Ⅲ-level classification scheme. The overall accuracy of the land use classification at Anderson level Ⅰ were 89.7% （1985）, 91.6% （1993）, and 90.4% （2001）. The most rapid land use change was a dramatic increase in urban or built-up areas, which quadrupled from 1985 to 2001. Over 90% of this newly expanded built-up area was originally paddy fields or other croplands. In different parts of the Zhejiang coastal region, urban land expansion was spatially uneven. Temporally, land use development did not stabilized, and the two study periods of time （1985-1993 and 1993-2001） had different transition styles. Socioeconomic factors, such as gross domestic product, total population, and financial expenditure, were all highly correlated with the expansion of urban or built-up areas. Based on the degree of urban sprawl and socioeconomic factors, cities and towns were further divided into six subgroups, which may help decision makers improve land use for the region.
基金National Natural Science Foundation of China, No.40571056 Sustentation Fund on Doctoral Thesis from Beijing Science and Technology Committee, No.ZZ0608
文摘Concerning about the rapid urban growth in recent China, this study takes Beijing as a case and puts forward that urban sprawl can be measured from spatial configuration, urban growth efficiency and external impacts, and then develops a geo-spatial indices system for measuring sprawl, a total of 13 indicators. In order to calculate these indices, different sources data are selected, including land use maps, former land use planning, land price and floor-area-ratio samples, digitized map of the highways and city centers, population and GDP statistical data, etc. Various GIS spatial analysis methods are used to spatialize these indices into 100mx100m cells. Besides, an integrated urban sprawl index is calculated by weight sum of these 13 indices. The application result indicates that geo-spatial indices system can capture most of the typical features and interior differentia of urban sprawl. Construction land in Beijing has kept fast growing with large amount, low efficiency and disordered spatial configuration, indicating a typical sprawling tendency. The following specific sprawl features are identified by each indicator： （1） typical spatial configuration of sprawling： obvious fragmentation and irregularity of landscape due to unsuccessful enforcement of land use planning, unadvisable pattern of typical discontinuous development, strip development and leapfrog development; （2） low efficiency of sprawl： low development density, low population density and economic output in newly developed area; and （3） negative impacts on agriculture, environment and city life. According to the integrated sprawl index, the sprawling amount in the northern part is larger than that in the southern, but the sprawling extent is in converse case; most sprawling area include the marginal area of the near suburbs and the area between highways, etc. Four sprawling patterns are identified： randomly expansion at urban fringe, strip development along or between highways, scattered development of industrial land, leapfrog development of urban residence and industrial area.
基金Knowledge Innovation Project of Chinese Academy of Sciences No.KZCX3-SW-427+1 种基金 National Natural Science Foundation of China No.40171044
文摘The Yangtze delta area is among the fastest developing areas in China. Here there are mega-cities like Shanghai, Nanjing and the attached urban areas of different sizes including those along the lower reaches of the Yangtze River from Shanghai up to Nanjing as well as their satellite cities and towns, forming one of the most densely distributed urban areas in China. This is a case study done in Suzhou city at the center of the Yangtze delta to reflect the impact of urban sprawl on soil resources using satellite images and digital soil databases. The extent of the developed land in the studied area and the impact of development on soil resources at 1:100,000 scale are estimated and the soil types impacted most by urbanization development are determined through overlaying the soil map on the satellite images (Landsat-7) of the studied area at different times (1984, 1995, 2000 and 2003). The methodology for this study consists of analyzing data resulting from using a geographic information system (GIS) to combine urban land use maps of different times derived from satellite images with data on soil characteristics contained in the established soil databases by which some results come into being to present the fast expanding trend of urbanization in the Yangtze delta area, the urban spread and the soils occupied by the urbanization process, and also the quality of the occupied soils.
基金supported by Natural Science Foundation of China (Grant no. 40671063)
文摘Urban expansion brought by the rapid progress of urbanization has caused many problems in China. It is a significant issue to evaluate the extent of urban expansion and to make appropriate controls over the sprawl of urban areas. With a comparative study of international experiences, this article analyzed the mechanism and consequences of urban expansion, reviewed the typical planning and financial policies adopted by other countries for controlling urban sprawl, and discussed the suitable densities of urban areas. The analysis results suggested that Chinese cities have no better choice but compact urban forms. To achieve the goal of compact development, intensive use of public transportation and high proportion of collective houses should be encouraged, and 60–100 m2 per capita is recommended as the reasonable range of urban density in large cities.
基金Under the auspices of National High Technology Research Development Program of China(No.2009AAA122005)National Natural Science Foundation of China(No.30700097,40701047)
文摘Urban sprawl is driven by a myriad of factors, the predominant one of which is the development of residential land. Selecting part of Jinan City for a case study, we use the landscape metric of percent of landscape (PLAND) to capture residential land growth and density changes in 1989, 1996 and 2004 to illuminate the dynamic process of residential land development. The results indicate that the moving window method and the landscape metrics method are efficient ways to describe residential land density. The residential land showed the greatest change among the built-up land with 1995.68 ha from 1989 to 2004, which is mainly transformed from agriculture land and green space. The urban center area of study area is primarily covered with medium density residential land, and surrounded by high density residential land. The development pattern of residential land exhibited both fill-in (new growth occurs through infilling the free spaces within the developed area) and sprawl processes, influenced by a series of factors, such as urban development policy, conservation of springs, recreational and aesthetic amenities. The findings of the study will help to guide urban planning with a focus on the management and protection of the environment and resources.
文摘Current global urbanisation processes are leading to new forms of massive urban constellations. The conceptualisations and classifications of these, however, are often ambiguous, overlap or lag behind in scientific literature. This article examines whether there is a common denominator to define and delimitate–and ultimately map–these new dimensions of cityscapes. In an extensive literature review we analysed and juxtaposed some of the most common concepts such as megacity, megaregion or megalopolis. We observed that many concepts are abstract or unspecific, and for those concepts for which physical parameters exist, the parameters are neither properly defined nor used in standardised ways. While understandably concepts originate from various disciplines, the authors identify a need for more precise definition and use of parameters. We conclude that often, spatial patterns of large urban areas resemble each other considerably but the definitions vary so widely that these differences may surpass any inconsistencies in the spatial delimitation process. In other words, today we have tools such as earth observation data and Geographic Information Systems to parameterise if clear definitions are provided. This appears not to be the case. The limiting factor when delineating large urban areas seems to be a commonly agreed ontology.
基金supported by the Humanities and Social Sciences Program of Jiangxi Universities(Grant No.GL21129)the Graduate Student Innovation Fund Program of Gannan Normal University(Grant No.YCX23A043)the Open Subject of Geography Discipline Construction of Gannan Normal University(Grant No.200084).
文摘With rapid economic development,the size of urban land in China is expanding dramatically.The Urban Growth Boundary(UGB)is an expandable spatial boundary for urban construction in a certain period in order to control the urban sprawl.Reasonable delineation of UGB can inhibit the disorderly spread of urban space and guide the normal development of the city.It is of practical significance for the construction of green urban space.The study utilizes GIS technology to establish a land construction suitability evaluation system for Nankang city,which is experiencing rapid urban expansion,and outlines the preliminary UGB under the future land use simulation(FLUS)model.At the same time,considering the coupled coordination of"Production-Living-Ecological Space",and based on the suitability evaluation,we revised the preliminary UGB by combining the advantages of the patch-generating land use simulation(PLUS)model and the convex hull model to delineate the final UGB.The results show that:1)the comprehensive score of the evaluation of the suitability of the construction of land from high to low shows the distribution of the center of the city to the surrounding circle type spread,the center of the city has the highest suitability score.The results of convex hull model show that the urban expansion type of Nankang is epitaxial.In the future,the urban expansion will mainly occur in the northern part of the city.The PLUS model predicts an increase of 3359.97 hm^(2)of construction land in Nankang by 2035,of which 2022.97 hm^(2)is urban construction land.2)The FLUS model has a prediction accuracy of 86.3%and delineates a preliminary UGB area of 9215.07 hm^(2).3)We used the results of the construction suitability evaluation,PLUS model simulation results,and convex hull model predictions to revise the originally delineated UGB.The final delineated UGB area is 8895.67 hm^(2)and it is capable of meeting the future development of the study area.The results of the delineation can promote sustainable urban development,and the delineation methodology can provide a reference basis for the preparation of territorial spatial planning.
文摘Urban land density is an important factor to understand how cities expand.An“Inverse S-shape Rule”was implemented for the first time to analyze urban land density in Northeastern Thailand using the four cities Khon Kaen,Udon Thani,Nakhon Phanom,and Nong Khai as study sites.Land density function was tested using different data classification techniques from previous studies.Each city was investigated over two different time periods between 2002 and 2015.Declining pattern characteristics of metropolitan area density outward from city centers can be quantified by fitting the parameters to urban land density functions.An inverse S-shape function was identified as the best data fit.The four selected cities showed conventional density variation for decline in urban land area from city centers to outlying areas.Overall trend indicated that cities became more compact over time since the density differences between the urban core and urban fringe were greater with increasing infilling growth within the urban boundary.All four cities increased in size over time;however,the increasing amount of built-up land in the surrounding rural areas did not follow the same trend in each case.Some functional parameters required careful interpretation because of the linear shape of the city as in the case of Nakhon Phanom.Using highly detailed urban data resulted in lower densities of urban areas compared to the conventional pixel-based classification,and this affected the overall shape of the inverse S-shape function.The fitted parameters and their changing trends indicated that the urban land density function was useful for understanding urban form and urban sprawl in Thailand.Results can be used to develop a specific framework for other cities with similar attributes in the future.
基金Funding for this research was given under Award No.R.G.P2/75/41 by the Deanship of Scientific ResearchKing Khalid University,Ministry of Education,Saudi Arabia.
文摘Given that many cities in Saudi Arabia have been observing rapid urbanization since the 1990s,scarce studies on the spatial pattern of urban expansion in Saudi Arabia have been conducted.Therefore,the present study investigates the evidence of land use and land cover(LULC)dynamics and urban sprawl in Abha City of Saudi Arabia,which has been experiencing rapid urbanization,from the past to the future using novel and sophisticated methods.The SVM classifier was used in this study to classify the LULC maps for 1990,2000,and 2018.The LULC dynamics between 1990–2000,2000–2018,and 1990–2018 have been analyzed using delta()change and the Markovian transitional probability matrix.Urban sprawl or urban expansion was modeled using two approaches,such as landscape fragmentation and presence frequency for the first time.The future LULC map for 2028 was predicted using the artificial neural network-cellular automata model(ANN-CA).Future LULC was analyzed using landscape fragmentation and frequency approaches.The results of LULC maps showed that urban areas increased by 334.4%between 1990 and 2018.The Delta change rate showed that 16.34%in urban areas has increased since 1990.While,the transitional probability matrix between 1990 and 2018 reported that the built-up area is the largest stable LULC,having an 83.6%transitional probability value.While 17.9%,21.8%,12.4%,and 10.5%of agricultural land,scrubland,exposed rocks,and water bodies were transformed into built-up areas.Urban sprawl models showed that 139 km^(2)of new urban areas had been set up in 2018,49 and 69 km^(2)in 1990 and 2000.Furthermore,in 2018,more than 200%of urban areas were stabilized or became core urban areas.The future LULC map(2028)showed that the built-up area would be 343.72 km^(2),followed by scrubland(342.98 km^(2))and sparse vegetation(89.96 km^(2)).The new urban area in 2028 would be 169 km^(2).The authorities and planners should focus more on the sustainable development of urban areas;otherwise,it would harm the natural and urban environment.
文摘Several factors may contribute to on-going challenges for spatial planning and policy in megacities such as Rome, including rapid population shifts, poorly organized areas, and lack of data through which monitoring urban growth and land use change. This research was conducted to examine past and current effects of the urbanization process, occurred over the large Roman urban system, on the basis of multi-source and multi-temporal optical remote sensing (RS) data, collected between 1990 and 2013. These changes were then validated via Geographic Information System (GIS) techniques, in a particular procedure applied to urban land/agricultural transformations. The proposed approach, based on geo-statistical methods, was used to calculate the index of innovative space (AP Index), useful for the monitoring of the urban sprawl phenomenon. Strong evidence of urban expansion over the north-eastern quarter of the city, accompanied by environmental degradation and loss of biodiversity, is provided. Urban infill developments are expected to emerge in the south-eastern areas too, and these might increase urban pressure as well. In conclusion, RS and GIS technologies together with ancillary data can be used to assist decision makers in preparing future plans to find out appropriate solutions to urbanization encroachment.
文摘Taking Harare metropolitan province in Zimbabwe as an example, we classified Landsat imagery (1984, 2002, 2008 and 2013) by using support vector machines (SVMs) and analyzed built-up and non-built-up changes. The overall classification accuracy for the four dates ranged from 89% to 95%, while the overall kappa varied from 86% to 93%. The results demonstrate that SVMs provide a cost-effective technique for mapping urban land use/cover by using mediumresolution satellite images such as Landsat. Based on land use/cover maps for 1984, 2002, 2008 and 2013, along with change analyses, built-up areas increased from 12.6% to 36.3% of the total land area, while non-built-up cover decreased from 87.3% to 63.4% between 1984 and 2013. The results revealed an urban growth process characterized by infill, extension and leapfrog developments. Given the dearth of spatial urban growth information in Harare metropolitan province, the land use/cover maps are valuable products that provide a synoptic view of built-up and non-built-up areas. Therefore, the land use/cover change maps could potentially assist decision-makers with up-to-date built-up and non-built-up information in order to guide strategic implementation of sustainable urban land use planning in Harare metropolitan province.
基金Under the auspices of Key Projects in the National Science&Technology Pillar Program During the Twelfth Five-year Plan Period(No.2012BAH28B02)
文摘To shed light on the general patterns and trends in urban sprawl research,and to provide reference for future study,bibliometric analysis and refined analysis are conducted for publications in this area from 1991 to 2011.The general publication output,the global geographical distribution of the authors,the funding and institutions involved,the research areas,and the source titles are analyzed and discussed.Scholars in the United States and China have produced most of the documents in urban sprawl and these two countries are also the largest contributors in terms of funding and institutions.′Environmental Sciences&Ecology′,′Urban Studies′,and′Geography′are the most common research areas,and the journal titled Urban Studies has contributed the most articles.Furthermore,the refined analyses on the 500 top-cited and most relevant publications have revealed that research on urban sprawl is closely associated with the categories of′Urban form and development′,′Land use/land development′and′environment/ecology/biology′.Conclusions are made with respect to the basic paradigm of research on urban sprawl.The multi-disciplinary research into urban sprawl are expected to be more diversified and integrated.
基金This work was supported in part by the National Natural Science Foundation of China(No.51605393)China Postdoctoral Science Foundation(No.2018M633398)+1 种基金State Key Laboratory of Robotics and Systems(HIT)(SKLRS-2020-KF-13)Sichuan Science and Technology Program(2020YJ0035).
文摘Inspired by the cockroach’s use of a pitch-roll mode traverses through narrow obstacles,we improve the RHex-style robot by adding two sprawl joints to adjust the body posture,and propose a novel pitch-roll approach that enables an RHex-style robot to traverse through two cylindrical obstacles with a spacing of 90 mm,about 54%body width.First,the robot can pitch up against the obstacle on the one side by the cooperation of its rear and middle legs.Then,the robot rotates one side rear leg to kick the ground fast,meanwhile the sprawl joint on the other side rotates inward to make the robot roll and fall forward.Finally,the robot can rotate the legs on the ground to move the body forward until it crosses the obstacles.In this article,both cylinder and rectangular columns are considered as the narrow obstacles for traversing.The experiments are demonstrated by using the proposed approach,and the results show that the robot can smoothly traverse through different narrow spaces.
基金National Key Research and Development Program of China,No.2022YFC3800101。
文摘Urban sprawl has been a prevailing phenomenon in developing countries like China,potentially resulting in significant carbon dioxide(CO_(2))emissions from the transport sector.However,the impact of urban sprawl on transport CO_(2) emissions(TCEs)is still not fully understood and remains somewhat rudimentary.To systematically investigate how urban sprawl influences TCEs,we employ panel regression and panel threshold regression for 274 Chinese cities(2005-2020),and obtain some new findings.Our results affirm that the degree of urban sprawl is positively associated with TCEs,and this holds true in different groups of city size and geographical region,while significant heterogeneity is observed in terms of such impact.Interestingly,we find urban sprawl nonlinearly impacts TCEs—with an equal increase in urban sprawl degree,TCEs are even lower in cities with larger population size and better economic condition,particularly in East China.Furthermore,the low-carbon city pilot policy shows potential in mitigating sprawl's impact on TCEs.Drawing on our findings,we argue that to achieve the target of TCEs reduction in China by curbing urban sprawl,more priority should be placed on relatively small,less developed,and geographically inferior cities for cost-efficiency reasons when formulating future urban development strategies.
文摘Today, climate change imposes enormous challenges on a global scale. The interactions of the balances between the need for development, population growth, massive urbanization generate a negative impact on the presence of these climate changes. One of the direct consequences of these changes is the phenomenon of flash floods, a phenomenon that hit the city of Jeddah (city located in west of Saudi Arabia) twice, one in 2009 and the other in 2011, causing significant human and material damage. Floods are considered as a direct result of the combination of extreme weather and hydrological phenomena;in most cases, the magnitude of these floods is magnified by anthropogenic factors, which increases the risk. According to the risk triangle, risk is defined as a probabilistic function that depends on three essential elements: exposure, vulnerability and hazard. If any of these three elements undergo growth the risk also does so and vice versa. Exposure and vulnerability will depend on the presence of human activities in the study area. This study is conducted on the Wadi Goss watershed as it was one of the most violent basins during the 2009 and 2011 floods. Indeed, we present in this study the extent of the urban extension in the Wadi Goss watershed, since 1984 to days and this by the using Landsat images. Given the nature of the study area, we present a method based on the calculation of various indices followed by a classification operation in order to define the urbanized zones inside the Wadi Goss watershed and then estimate the urban sprawl inside the watershed. We also present in this paper, the characteristics of the watershed as well as the evolution of the urbanized areas exposed to the phenomenon of floods and their contribution to the changes of the hydrological behavior of the basin, and to increase the evolution of the risk of the floods. We have shown through this study that the urban footprint has increased from 90 hectares in 1985 to 850 hectares in 2015. This urban footprint represents 12% of the total area of the watershed. Most of the urban evolution was operated on the wadi area with a concentration in the western part of the basin and especially at its outlet.
