Against the backdrop of the sizable economic growth of China in recent years, this paper uses the most recent data gathering of the Globalization and World Cities(Ga WC) research network to update and supplement earli...Against the backdrop of the sizable economic growth of China in recent years, this paper uses the most recent data gathering of the Globalization and World Cities(Ga WC) research network to update and supplement earlier research on the shifting global connectivity of Chinese cities. The update consists of an evaluation of the connectivity of Chinese cities in 2016, the supplement of an analysis of the changing position of Chinese cities in the world city network between 2010 and 2016. To this end, we build on a specification of the world city network as an ‘interlocking network' in which producer services firms play the crucial role in city network formation. Information about the presence of leading producer services firms in cities in 2010 and 2016 is used as the input to a bipartite network projection algorithm in order to measure cities' network connectivity. The first set of results discusses the geographies of urban connectivity in the world city network in 2016. The second set of results discusses standardized measures of change to reveal the major dimensions of the transformations between 2010 and 2016. We find that, with the exception of Hong Kong, Macao and Kaohsiung of Taiwan, all Chinese cities record connectivity gains. This wholesale rise in connectivity is nonetheless geographically uneven, with above all Beijing, Chengdu/Chongqing and Changsha/Wuhan becoming more connected. We conclude that the wholesale rise of Chinese cities in the world city network and their changing trajectories in the post-crisis era are embedded in shifting external and internal political economies.展开更多
Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·...Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·Mg2+ or HCO3--Mg2+·Ca2+; SO42--Ca2+ and SO42--Ca2+·Mg2+; Cl--Ca2+; and CO32--Na+. The deteriorations of groundwater quality due to the increase of TDS, NO3-+ NO2-(as Nitrogen) and TH contents have been observed from 1991 to 1998. Scatter analyses showed strong positive correlations between Ca2+, Cl-and NO3-ions and weak negative correlations between the depth of water table and Ca2+, SO42-, Cl-and NO3-ions. A mapping of contaminant index based on Chinese standard of groundwater showed that a large proportion of the groundwater in 1998 was deteriorated by human process. Despite their low values of sodium adsorption ratio (SAR), the most of the sampled wells were not suitable for drinking and agriculture purposes due to higher contents of NO3-, NO2-and Mn2+ ions.展开更多
An-Najaf province is situated in south-western part of Iraq. It is 70 meters above the sea level in the dry desert environment. The city is considered as one of the most important cities in Iraq, facing a fast populat...An-Najaf province is situated in south-western part of Iraq. It is 70 meters above the sea level in the dry desert environment. The city is considered as one of the most important cities in Iraq, facing a fast population growth and continuous development in constructions such as residential complexes, hotels, bridges and shopping malls. Soil investigation data for An-Najaf Province (An-Najaf and Kufa cities) from 464 boreholes drilled by the Na-tional Centre for Construction Laboratories & Researches (NCCLR)/Babylon laboratory were used in this research. The data were analysed and possessed using Excel program then represented on the Geographical Information System (GIS) program by Inverse Distance Weighted (IDW) tool to create an allowable bearing capacity map for the soil at depths 0 - 2 meters. The allowable bearing capacity is one of the most important soil characteristics to be considered when making a database for An-Najaf city soil. Geographical Information System GIS program enables to create reliable database for any characteristic and it is one of the best programs to produce an accurate map and allow ease in dealing with it. Those maps cover all the studied areas and by using contour lines, approximate values for no-data areas can be obtained. The results show that the allowable bearing capacity range is 5 - 20 Ton/m2 for both An-Najaf and Kufa cities. Kufa city has the range 5 - 9 Ton/m2. An-Najaf city has the range 7 - 18 at the center, 8 - 10 Ton/m2 at the north eastern part, 7 - 14 Ton/m2 for the north western part, 6 - 12 Ton/m2 at the south eastern and 12 - 19 Ton/m2 at the south western.展开更多
By using GIS, RS and landscape ecology, LandsatTM (1993 and 2009) and ETM (2001) remote sensing images of Licheng District of Ji’nan City, Shandong Province were interpreted, and dynamic changes of landscape pattern ...By using GIS, RS and landscape ecology, LandsatTM (1993 and 2009) and ETM (2001) remote sensing images of Licheng District of Ji’nan City, Shandong Province were interpreted, and dynamic changes of landscape pattern in the district were analyzed at the levels of class and landscape. The results showed that during the 16 years the landscape pattern in the district had changed significantly. (a) From the perspective of patch category, areas of arable land, woodland and grassland decreased unceasingly, and arable land accounted for the largest reduction from 488.15 km 2 in 1993 down to 324.37 km 2 in 2009, witnessing a reduction rate of 33.56%. But the patch quantity and fragmentation increased, patch connectivity reduced. Spatial pattern of construction land expanded and its area witnessed a significant increase of 147.05%. Patch cohesion index increased and connectivity grew better. (b) From the perspective of overall landscape, patch quantity, contagion and perimeter-area fractal dimension decreased, patch shape became simple, the Shannon’s diversity index, Shannon’s evenness index and splitting index increased, landscape heterogeneity rose. With the rapid social and economic development, landscape pattern will be more and more influenced by human behaviors展开更多
[Objective] The aim was to explore interannual changes of soil nutrients in tobacco soils in Zhaotong, in order to provide theoretical references for tobacco bal- anced fertilization in Zhaotong. [Method] The research...[Objective] The aim was to explore interannual changes of soil nutrients in tobacco soils in Zhaotong, in order to provide theoretical references for tobacco bal- anced fertilization in Zhaotong. [Method] The research analyzed nutrient changes in tobacco soils in Zhaotong during 2011-2013. [Result] In Zhaotong, pH value of to- bacco soils was increasing; the contents of organic matter and N, P and K contents were in the range suitable for tobacco growth; CI- content was growing in tobacco soils and reached the highest in 2013. [Conclusion] In general, soil nutrients show insignificant differences internannually in Zhaotong.展开更多
The Ecological-living-productive land(ELPL)classification system was proposed in an effort to steer China's land pattern to an ecological-centered path,with the development model shifting from a single function in...The Ecological-living-productive land(ELPL)classification system was proposed in an effort to steer China's land pattern to an ecological-centered path,with the development model shifting from a single function into more integrated multifunction land use.The focus is coordinating the man-land contradictions and developing an intensive,efficient and sustainable land use policy in an increasingly tense relationship between humans and nature.Driven by socioeconomic change and rapid population growth,many cities are undergoing urban sprawl,which involves the consumption of cropland and ecological land and threatens the ecological balance.This paper aims to quantitatively analyze the critical effects of ELPL changes on eco-environmental quality according to land use classification based on leading function of ecology,living and production from 1990 to 2015 with a case study of Xining City.Also,four future land use scenarios were simulated for 2030 using the Future Land Use Simulation(FLUS)model that couples human and natural effects.Our results show a decrease in productive land(PL)and an increase in ecological land(EL)and living land(LL)in Xining City.Forestry ecological land(FEL)covered the top largest proportion;agriculture productive land(APL)showed the greatest reduction and urban and rural living land(U-RLL)presented a dramatic increase.The eco-environmental quality improved in 1990-2010,mainly affected by the conversion of APL to FEL and GEL.However,the encroachment of U-RLL into APL,other ecological land(OEL)and FEL was the main contributor to the decline in eco-environmental quality in 2010-2015 as well as the primary reason for the increase area of lower-quality.The Harmonious Development(HD)-Scenario,characterized by a rational allocation of LL and PL and a better eco-environment,would have implications for planning and monitoring future management of ELPL,and may represent a valuable reference for local policy-makers.展开更多
The degree of spatial similarity plays an important role in map generalization, yet there has been no quantitative research into it. To fill this gap, this study first defines map scale change and spatial similarity d...The degree of spatial similarity plays an important role in map generalization, yet there has been no quantitative research into it. To fill this gap, this study first defines map scale change and spatial similarity degree/relation in multi-scale map spaces and then proposes a model for calculating the degree of spatial similarity between a point cloud at one scale and its gener- alized counterpart at another scale. After validation, the new model features 16 points with map scale change as the x coordinate and the degree of spatial similarity as the y coordinate. Finally, using an application for curve fitting, the model achieves an empirical formula that can calculate the degree of spatial similarity using map scale change as the sole independent variable, and vice versa. This formula can be used to automate algorithms for point feature generalization and to determine when to terminate them during the generalization.展开更多
Landscape of Dhaka city—one of the fastest growing mega cities in the world, is continuously changing due to un-planned urbanization. For example, the wetlands of the city have been shrinking. This study evaluates we...Landscape of Dhaka city—one of the fastest growing mega cities in the world, is continuously changing due to un-planned urbanization. For example, the wetlands of the city have been shrinking. This study evaluates wetland changes in Dhaka Metropolitan Area (DMA), Bangladesh, between 1978 and 2009. Spatial and temporal dynamics of wetland changes were quantified using four Landsat images, a supervised classi?cation algorithm and the post-classi?cation change detection technique in GIS environment. Accuracy of the Landsat-derived wetland maps ranged from 87% to 92.5%. The analysis revealed that area of wetland and Rivers & Khals in Dhaka city decreased significantly over the last 30 years by 76.67% and 18.72% respectively. This changing trend of wetlands makes the drainage system of Dhaka City vulnerable, creating water logging problems and their consequences. Land filling and encroachment were recognized to be the main reasons for shrinking of the wetlands in the city. Development and alteration of the existing water bodies should consider the natural hydrological conditions.展开更多
True color image city map is a sort of new-style map which combines the high resolution image and map symbols and shows both advantages in visualization. At the same time, the map unification and harmonization should ...True color image city map is a sort of new-style map which combines the high resolution image and map symbols and shows both advantages in visualization. At the same time, the map unification and harmonization should be taken into account dur-ing the design process, since some visual conflicts appear when map symbols overlaid on the true color image. The objective of this research is to explore the rules in the process of true color image city map design based on chromatic and aesthetic knowledge. At the end, taking the Image Atlas of Guangzhou as an example, image color adjustment, road network presentation, and symbol de-signing issues will be discussed in the application.展开更多
The relatively rapid recession of glaciers in the Himalayas and formation of moraine dammed glacial lakes(MDGLs) in the recent past have increased the risk of glacier lake outburst floods(GLOF) in the countries of Nep...The relatively rapid recession of glaciers in the Himalayas and formation of moraine dammed glacial lakes(MDGLs) in the recent past have increased the risk of glacier lake outburst floods(GLOF) in the countries of Nepal and Bhutan and in the mountainous territory of Sikkim in India. As a product of climate change and global warming, such a risk has not only raised the level of threats to the habitation and infrastructure of the region, but has also contributed to the worsening of the balance of the unique ecosystem that exists in this domain that sustains several of the highest mountain peaks of the world. This study attempts to present an up to date mapping of the MDGLs in the central and eastern Himalayan regions using remote sensing data, with an objective to analyse their surface area variations with time from 1990 through 2015, disaggregated over six episodes. The study also includes the evaluation for susceptibility of MDGLs to GLOF with the least criteria decision analysis(LCDA). Forty two major MDGLs, each having a lake surface area greater than 0.2 km2, that were identified in the Himalayan ranges of Nepal, Bhutan, and Sikkim, have been categorized according to their surface area expansion rates in space and time. The lakes have been identified as located within the elevation range of 3800 m and6800 m above mean sea level(a msl). With a total surface area of 37.9 km2, these MDGLs as a whole were observed to have expanded by an astonishing 43.6% in area over the 25 year period of this study. A factor is introduced to numerically sort the lakes in terms of their relative yearly expansion rates, based on their interpretation of their surface area extents from satellite imageries. Verification of predicted GLOF events in the past using this factor with the limited field data as reported in literature indicates that the present analysis may be considered a sufficiently reliable and rapid technique for assessing the potential bursting susceptibility of the MDGLs. The analysis also indicates that, as of now, there are eight MDGLs in the region which appear to be in highly vulnerable states and have high chances in causing potential GLOF events anytime in the recent future.展开更多
Based on the CCD images,IIM data and DEM data of China's lunar exploration project (Chang'E-Ⅰ) and related processed and analytic results,an integrated study of regional geology of Sinus Iridum and its adjacent a...Based on the CCD images,IIM data and DEM data of China's lunar exploration project (Chang'E-Ⅰ) and related processed and analytic results,an integrated study of regional geology of Sinus Iridum and its adjacent area was conducted,and a series of relevant researches and analyses were carried out,including analysis of impact craters and their extrusive and accumulative materials,division of stratigraphic and tectonic units and classification of rock types,integrated analysis of chronology and lunar evolution history.In consideration of crater's shape features,quantity and preserving status of filling materials,the lunar impact craters can be divided into 7 types and 11 subtypes,and the accumulative materials of craters are divided into 6 types and 9 accumulative groups.According to the content and distribution of TiO2 and image characteristics,the basalts are divided into high-TiO2,medium-TiO2 and low-TiO2 basalts.Discussion was made on division of tectonic units and evolution features in the study area.The geological map of the Sinus Iridum Quadrangle (LQ-4) at a scale of 1∶2.5 M was preliminarily compiled with the ArcGIS system,and the spatial database of the map was established.Related technical specification,procedure and method for lunar geological mapping have been worked out,so as to lay a foundation for the forthcoming geological mapping of the global Moon in China by using the data of Chang'E-Ⅱ and also for comprehensive study and geological mapping of other celestial bodies in the future.展开更多
Knowledge on the potential suitability of tree species to the site is very important for forest management planning.Natural forest distribution provides a good reference for afforestation and forest restoration.In thi...Knowledge on the potential suitability of tree species to the site is very important for forest management planning.Natural forest distribution provides a good reference for afforestation and forest restoration.In this study,we developed species distribution model(SDM)for 16 major tree species with 2,825 permanent sample plots with natural origin from Chinese National Forest Inventory data collected in Jilin Province using the Maxent model.Three types of environmental factors including bioclimate,soil and topography with a total of 33 variables were tested as the input.The values of area under the curve(AUC,one of the receiver operating characteristics of the Maxent model)in the training and test datasets were between 0.784 and 0.968,indicating that the prediction results were quite reliable.The environmental factors affecting the distribution of species were ranked in terms of their importance to the species distribution.Generally,the climatic factors had the greatest contribution,which included mean diurnal range,annual mean temperature,temperature annual range,and iosthermality.But the main environmental factors varied with tree species.Distribution suitability maps under current(1950-2000)and future climate scenarios(CCSM4-RCP 2.6 and RCP 6.0 during 2050)were produced for 16 major tree species in Jilin Province using the model developed.The predicted current and future ranges of habitat suitability of the 16 tree species are likely to be positively and negatively affected by future climate.Seven tree species were found to benefit from future climate including B etula costata,Fraxinus mandshurica,Juglans mandshurica,Phellodendron amurense,Populus ussuriensis,Quercus mongolica and Ulmus pumila;five tree species will experience decline in their suitable habitat including B.platyphylla,Tilia mongolica,Picea asperata,Pinus sylvestris,Pinus koraiensis;and four(Salix koreensis,Abies fabri,Pinus densiflora and Larix olgensis)showed the inconsistency under RCP 2.6 and RCP 6.0 scenarios.The maps of the habitat suitability can be used as a basis for afforestation and forest restoration in northeastern China.The SDMs could be a potential tool for forest management planning.展开更多
The three-period (1995, 1998 and 2003) remote sensing images in Jinan City, China are selected. And the information of green land, construction land, woodland and water body is extracted by using the image processing ...The three-period (1995, 1998 and 2003) remote sensing images in Jinan City, China are selected. And the information of green land, construction land, woodland and water body is extracted by using the image processing module of remote-sensing software and computerized interpretation module. Both the change table and transfer matrix table of land use area are analyzed by modeling module of remote-sensing software. Then, the Geo-information Tupu is obtained; and the temporal and spatial variation of land use in Jinan City is monitored and analyzed by Geo-information Tupu and transfer matrix. Result shows that land use structure change of Jinan City in the years 1995-1998 shows a transformation from green land to construction land. Area of green land circulating into construction land reaches 62.27 square kilometers, accounting for 25.84% of the initial green land. In the year 1998, areas of woodland and green land are reduced due to the urban expansion of Jinan City. However, with the enhancement of people's awareness of environmental protection, areas of woodland and green land gradually increase in the year 2003, which are still less than those in the year 1995.展开更多
Based on the satellite remote sensing TM/ETM images of Xuzhou city, basic data about land use of the city from 1994 to 2000 are obtained with the neural network classification module of PCI software, and the dynamic c...Based on the satellite remote sensing TM/ETM images of Xuzhou city, basic data about land use of the city from 1994 to 2000 are obtained with the neural network classification module of PCI software, and the dynamic con- version matrix of land use is thus calculated. The areas of construction land and water body have increased by 1833.93 hm2 and 804.87 hm2, respectively. On the contrary, the area of cropland has decreased by 3207.24 hm2. The area of cropland converted into construction land makes up 26.84%, and that converted into water body amounts for 8.17% of the total area of cropland in 1994. The variation index of land use degree and the dynamic degree index of land use computed are 1.38 and 57.81%, respectively, which demonstrate that land use in Xuzhou is in a development period and the changes are drastic. The frequency index and importance index of the form in which cropland converted into con- struction land are 29.91% and 68.93% respectively. The results indicate that the change is not only widespread in space but a major form of spatial change of land use in the area.展开更多
Appraisaling the land-use change degree of urban land objectively, analyzing the reasons, and proposing the countermeasures have important meanings to promote land sustainable development. The article analyzed the dyn...Appraisaling the land-use change degree of urban land objectively, analyzing the reasons, and proposing the countermeasures have important meanings to promote land sustainable development. The article analyzed the dynamic change of land-use ecological footprint in Harbin City from 1996 to 2006. Through the measurement of ecological footprint to assess the social impact and the extent of sustainable land-use. The results showed that the per capita ecological footprint in Harbin had increased year by year, while the per capita ecological carrying capacity had decreased, the per capita ecological deficit was increasing, and land-use in Harbin City was in an overload status. Finally, reasonable land-use proposals were proposed.展开更多
[Objectives] The land use change and its influence has been the frontier and hotspot in the research of the surface process of change. The aim of this study was to provide a reasonable scientific basis for the more re...[Objectives] The land use change and its influence has been the frontier and hotspot in the research of the surface process of change. The aim of this study was to provide a reasonable scientific basis for the more reasonable use of regional land resources of Bole City by study of land use change and driving force of Bole City.[Methods] Through geometric correction, image mosaic and image registration processing and classification of the remote sensing images of Bole City in 2006, 2011 and 2016, the three images of land use change in land use types (land use change range, dynamic degree and variation degree) were studied, and the natural and social economy in terms of the driving forces of land use change were analyzed.[Results] In the 2006 to 2016 period, cultivated land of Bole City had the land use dynamic growth state, and the average growth rate was 0.26%; and forest land, construction land, water, grassland and unused land showed a decreasing trend, decreased by 0.23%, 0.22%, 0.75%, 3.85% and 1.52%, respectively. In the entire study period, the change of grassland was the biggest, the changes of unused land and water were the second, and the changes of cultivated land, construction land and forest land were lesser.[Conclusions] The main driving factors that effected on land use change of the study area were climate, industrialization, urbanization, social and economic activities, adjustment of agricultural structure and population expansion.展开更多
[Objective] The research aimed to study the variation characteristics of climate and its influence on the crop farming in Xintai City.[Method] By using the yearly and monthly average temperature,rainfall,first and las...[Objective] The research aimed to study the variation characteristics of climate and its influence on the crop farming in Xintai City.[Method] By using the yearly and monthly average temperature,rainfall,first and last frost dates,frost-free period,sunshine hours,etc.in Xintai City during 1957-2009,the variation characteristics of climate and its influence on the crop farming in Xintai City in recent 53 years were analyzed.[Result] The temperature rose in the fluctuation in Xintai City.The warm winter phenomenon was prominent,and ≥0℃ accumulated temperature increased yearly.In recent 10 years,the first frost postponed,and the last frost advanced.The growth season of crop prolonged.The annual rainfall decreased in the fluctuation,and the annual sunshine hours presented the decrease trend as a whole.For the accumulated temperature increased,and the frost-free period prolonged,the sowing date and farming system of main crops in Xintai City changed.The rising of winter temperature was favorable for the development of industrialized agriculture,such as the warm house booth.The multiple-cropping index improved,and the characteristic planting advantage was prominent.The climate warming made that the planting areas of yellow ginger and day lily enlarged,and the planting boundary moved northward.The sowing dates of wheat and peanut postponed.The sowing date of yellow ginger advanced,and the growth period prolonged.Meanwhile,the climate variation also made that the plant diseases and insect pests,spring frozen injury aggravated in Xintai.The influence of extreme weather induced by the increasing of extreme climate event on the yield and quality of fruit tree was stronger.The planting risks of yellow ginger and day lily increased.[Conclusion] The research provided the scientific basis for promoting the sustainable development of economic society in Xintai.展开更多
Climate change is an inevitable trend,which challenges security of water resources in China,especially in cities.Assessing vulnerability of water resource to climate change in cities has important role for policy make...Climate change is an inevitable trend,which challenges security of water resources in China,especially in cities.Assessing vulnerability of water resource to climate change in cities has important role for policy makers. The paper constructs a vulnerability function,including exposure,sensitivity and adaptive capacity,according to the vulnerability concept proposed by IPCC,establishes an assessment indicators system of water resources to climate change in cities,and analyzes vulnerability features of Chinese cites based on 655 cities'data in 2006.The vulnerability assessment results show that there are distinctive differences among all the cities,between east,central and west cities,between ordinary,big and mega cities,while there is no statistical significant difference between north and south cities.Based on the research,the paper suggests that strategic emphasis should focus on the central cities and ordinary cities展开更多
Studies on carbon emissions associated with land use and cover change(LUCC)are key to understanding the impact of human activities on regional sustainability.In this study,we analyzed the temporal and spatial changes ...Studies on carbon emissions associated with land use and cover change(LUCC)are key to understanding the impact of human activities on regional sustainability.In this study,we analyzed the temporal and spatial changes in carbon emissions associated with LUCC for production,living,and ecological spaces in Zhengzhou City of China.Landsat remote sensing images were used to classify the land use and land cover(LULC)types in Zhengzhou City in 1988,2001,2009,and 2015.Carbon emissions associated with LUCC were evaluated using a spatial gradient model and the niche mechanism.It was found that during 1988-2015,carbon emissions associated with LUCC in Zhengzhou City increased by 17.1×10^(6) t,while the carbon sink resulted from cultivated land,forests,water bodies,and unused land decreased significantly.Most of the increase in carbon emissions associated with LUCC occurred in the center of the city.The peak carbon emissions were located in the northeastern,southeastern,northwestern,and southwestern regions of Zhengzhou City,and carbon emissions varied considerably in the different spatial gradient rings over time.Among the three spaces,carbon emissions associated with LUCC were mainly affected by the living space.The population size and population urbanization rate were negatively correlated with the ecological space and positively correlated with the production and living spaces.Our results highlight that Zhengzhou City should take the new urbanization path of urban transformation development and ecological civilization construction to ensure the realization of the promised carbon emission reduction targets.展开更多
Iain Sinclair, in his Lights Out for the Territory (1997) declared that "walking is the best way to explore and exploit the city". But what exactly is that we are looking for in our contemporary cities? And how c...Iain Sinclair, in his Lights Out for the Territory (1997) declared that "walking is the best way to explore and exploit the city". But what exactly is that we are looking for in our contemporary cities? And how can walking contribute in tracing (explore) and therefore mapping (exploit) all those elements or situations that we seek for? Urban space is constantly mutating. Our experience of space as a practiced place changes gradually as the "sterile" private spaces and misleading billboards, the neo-urban surrounding urban environment evolves around us. Amidst walker drifts through the city in search for the peculiar, the original, the intriguing, and the fringe. An urban journey/drifting starts and ends without any predefined plan in mind, while remaining alert and receptive to all incentives given by the practiced urban locus (audio, visual, olfactory, and psychological incentives). Originating from the post-Romantic English writers and the mid-nineteenth century Parisian flaneur, urban drifting has been practiced in multiple ways with different outcomes, but yet highly contributory in the depiction and specific mapping of our urban environment. This paper attempts to investigate the roots of urban drifting, its evolution, and its potential utility as a spatial practice in visual arts, architecture, and mapping.展开更多
文摘Against the backdrop of the sizable economic growth of China in recent years, this paper uses the most recent data gathering of the Globalization and World Cities(Ga WC) research network to update and supplement earlier research on the shifting global connectivity of Chinese cities. The update consists of an evaluation of the connectivity of Chinese cities in 2016, the supplement of an analysis of the changing position of Chinese cities in the world city network between 2010 and 2016. To this end, we build on a specification of the world city network as an ‘interlocking network' in which producer services firms play the crucial role in city network formation. Information about the presence of leading producer services firms in cities in 2010 and 2016 is used as the input to a bipartite network projection algorithm in order to measure cities' network connectivity. The first set of results discusses the geographies of urban connectivity in the world city network in 2016. The second set of results discusses standardized measures of change to reveal the major dimensions of the transformations between 2010 and 2016. We find that, with the exception of Hong Kong, Macao and Kaohsiung of Taiwan, all Chinese cities record connectivity gains. This wholesale rise in connectivity is nonetheless geographically uneven, with above all Beijing, Chengdu/Chongqing and Changsha/Wuhan becoming more connected. We conclude that the wholesale rise of Chinese cities in the world city network and their changing trajectories in the post-crisis era are embedded in shifting external and internal political economies.
文摘Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·Mg2+ or HCO3--Mg2+·Ca2+; SO42--Ca2+ and SO42--Ca2+·Mg2+; Cl--Ca2+; and CO32--Na+. The deteriorations of groundwater quality due to the increase of TDS, NO3-+ NO2-(as Nitrogen) and TH contents have been observed from 1991 to 1998. Scatter analyses showed strong positive correlations between Ca2+, Cl-and NO3-ions and weak negative correlations between the depth of water table and Ca2+, SO42-, Cl-and NO3-ions. A mapping of contaminant index based on Chinese standard of groundwater showed that a large proportion of the groundwater in 1998 was deteriorated by human process. Despite their low values of sodium adsorption ratio (SAR), the most of the sampled wells were not suitable for drinking and agriculture purposes due to higher contents of NO3-, NO2-and Mn2+ ions.
文摘An-Najaf province is situated in south-western part of Iraq. It is 70 meters above the sea level in the dry desert environment. The city is considered as one of the most important cities in Iraq, facing a fast population growth and continuous development in constructions such as residential complexes, hotels, bridges and shopping malls. Soil investigation data for An-Najaf Province (An-Najaf and Kufa cities) from 464 boreholes drilled by the Na-tional Centre for Construction Laboratories & Researches (NCCLR)/Babylon laboratory were used in this research. The data were analysed and possessed using Excel program then represented on the Geographical Information System (GIS) program by Inverse Distance Weighted (IDW) tool to create an allowable bearing capacity map for the soil at depths 0 - 2 meters. The allowable bearing capacity is one of the most important soil characteristics to be considered when making a database for An-Najaf city soil. Geographical Information System GIS program enables to create reliable database for any characteristic and it is one of the best programs to produce an accurate map and allow ease in dealing with it. Those maps cover all the studied areas and by using contour lines, approximate values for no-data areas can be obtained. The results show that the allowable bearing capacity range is 5 - 20 Ton/m2 for both An-Najaf and Kufa cities. Kufa city has the range 5 - 9 Ton/m2. An-Najaf city has the range 7 - 18 at the center, 8 - 10 Ton/m2 at the north eastern part, 7 - 14 Ton/m2 for the north western part, 6 - 12 Ton/m2 at the south eastern and 12 - 19 Ton/m2 at the south western.
文摘By using GIS, RS and landscape ecology, LandsatTM (1993 and 2009) and ETM (2001) remote sensing images of Licheng District of Ji’nan City, Shandong Province were interpreted, and dynamic changes of landscape pattern in the district were analyzed at the levels of class and landscape. The results showed that during the 16 years the landscape pattern in the district had changed significantly. (a) From the perspective of patch category, areas of arable land, woodland and grassland decreased unceasingly, and arable land accounted for the largest reduction from 488.15 km 2 in 1993 down to 324.37 km 2 in 2009, witnessing a reduction rate of 33.56%. But the patch quantity and fragmentation increased, patch connectivity reduced. Spatial pattern of construction land expanded and its area witnessed a significant increase of 147.05%. Patch cohesion index increased and connectivity grew better. (b) From the perspective of overall landscape, patch quantity, contagion and perimeter-area fractal dimension decreased, patch shape became simple, the Shannon’s diversity index, Shannon’s evenness index and splitting index increased, landscape heterogeneity rose. With the rapid social and economic development, landscape pattern will be more and more influenced by human behaviors
基金Supported by China Tobacco Yunnan Industrial.Co.,Ltd S&T Project([2013]No.494)~~
文摘[Objective] The aim was to explore interannual changes of soil nutrients in tobacco soils in Zhaotong, in order to provide theoretical references for tobacco bal- anced fertilization in Zhaotong. [Method] The research analyzed nutrient changes in tobacco soils in Zhaotong during 2011-2013. [Result] In Zhaotong, pH value of to- bacco soils was increasing; the contents of organic matter and N, P and K contents were in the range suitable for tobacco growth; CI- content was growing in tobacco soils and reached the highest in 2013. [Conclusion] In general, soil nutrients show insignificant differences internannually in Zhaotong.
基金the support of the National Natural Science Foundation of China(No.41661038)Soft Science Research Project of Science and Technology Department of Qinghai province(No.2015-ZJ-602)
文摘The Ecological-living-productive land(ELPL)classification system was proposed in an effort to steer China's land pattern to an ecological-centered path,with the development model shifting from a single function into more integrated multifunction land use.The focus is coordinating the man-land contradictions and developing an intensive,efficient and sustainable land use policy in an increasingly tense relationship between humans and nature.Driven by socioeconomic change and rapid population growth,many cities are undergoing urban sprawl,which involves the consumption of cropland and ecological land and threatens the ecological balance.This paper aims to quantitatively analyze the critical effects of ELPL changes on eco-environmental quality according to land use classification based on leading function of ecology,living and production from 1990 to 2015 with a case study of Xining City.Also,four future land use scenarios were simulated for 2030 using the Future Land Use Simulation(FLUS)model that couples human and natural effects.Our results show a decrease in productive land(PL)and an increase in ecological land(EL)and living land(LL)in Xining City.Forestry ecological land(FEL)covered the top largest proportion;agriculture productive land(APL)showed the greatest reduction and urban and rural living land(U-RLL)presented a dramatic increase.The eco-environmental quality improved in 1990-2010,mainly affected by the conversion of APL to FEL and GEL.However,the encroachment of U-RLL into APL,other ecological land(OEL)and FEL was the main contributor to the decline in eco-environmental quality in 2010-2015 as well as the primary reason for the increase area of lower-quality.The Harmonious Development(HD)-Scenario,characterized by a rational allocation of LL and PL and a better eco-environment,would have implications for planning and monitoring future management of ELPL,and may represent a valuable reference for local policy-makers.
基金funded by the Natural Science Foundation Committee,China(41364001,41371435)
文摘The degree of spatial similarity plays an important role in map generalization, yet there has been no quantitative research into it. To fill this gap, this study first defines map scale change and spatial similarity degree/relation in multi-scale map spaces and then proposes a model for calculating the degree of spatial similarity between a point cloud at one scale and its gener- alized counterpart at another scale. After validation, the new model features 16 points with map scale change as the x coordinate and the degree of spatial similarity as the y coordinate. Finally, using an application for curve fitting, the model achieves an empirical formula that can calculate the degree of spatial similarity using map scale change as the sole independent variable, and vice versa. This formula can be used to automate algorithms for point feature generalization and to determine when to terminate them during the generalization.
文摘Landscape of Dhaka city—one of the fastest growing mega cities in the world, is continuously changing due to un-planned urbanization. For example, the wetlands of the city have been shrinking. This study evaluates wetland changes in Dhaka Metropolitan Area (DMA), Bangladesh, between 1978 and 2009. Spatial and temporal dynamics of wetland changes were quantified using four Landsat images, a supervised classi?cation algorithm and the post-classi?cation change detection technique in GIS environment. Accuracy of the Landsat-derived wetland maps ranged from 87% to 92.5%. The analysis revealed that area of wetland and Rivers & Khals in Dhaka city decreased significantly over the last 30 years by 76.67% and 18.72% respectively. This changing trend of wetlands makes the drainage system of Dhaka City vulnerable, creating water logging problems and their consequences. Land filling and encroachment were recognized to be the main reasons for shrinking of the wetlands in the city. Development and alteration of the existing water bodies should consider the natural hydrological conditions.
文摘True color image city map is a sort of new-style map which combines the high resolution image and map symbols and shows both advantages in visualization. At the same time, the map unification and harmonization should be taken into account dur-ing the design process, since some visual conflicts appear when map symbols overlaid on the true color image. The objective of this research is to explore the rules in the process of true color image city map design based on chromatic and aesthetic knowledge. At the end, taking the Image Atlas of Guangzhou as an example, image color adjustment, road network presentation, and symbol de-signing issues will be discussed in the application.
文摘The relatively rapid recession of glaciers in the Himalayas and formation of moraine dammed glacial lakes(MDGLs) in the recent past have increased the risk of glacier lake outburst floods(GLOF) in the countries of Nepal and Bhutan and in the mountainous territory of Sikkim in India. As a product of climate change and global warming, such a risk has not only raised the level of threats to the habitation and infrastructure of the region, but has also contributed to the worsening of the balance of the unique ecosystem that exists in this domain that sustains several of the highest mountain peaks of the world. This study attempts to present an up to date mapping of the MDGLs in the central and eastern Himalayan regions using remote sensing data, with an objective to analyse their surface area variations with time from 1990 through 2015, disaggregated over six episodes. The study also includes the evaluation for susceptibility of MDGLs to GLOF with the least criteria decision analysis(LCDA). Forty two major MDGLs, each having a lake surface area greater than 0.2 km2, that were identified in the Himalayan ranges of Nepal, Bhutan, and Sikkim, have been categorized according to their surface area expansion rates in space and time. The lakes have been identified as located within the elevation range of 3800 m and6800 m above mean sea level(a msl). With a total surface area of 37.9 km2, these MDGLs as a whole were observed to have expanded by an astonishing 43.6% in area over the 25 year period of this study. A factor is introduced to numerically sort the lakes in terms of their relative yearly expansion rates, based on their interpretation of their surface area extents from satellite imageries. Verification of predicted GLOF events in the past using this factor with the limited field data as reported in literature indicates that the present analysis may be considered a sufficiently reliable and rapid technique for assessing the potential bursting susceptibility of the MDGLs. The analysis also indicates that, as of now, there are eight MDGLs in the region which appear to be in highly vulnerable states and have high chances in causing potential GLOF events anytime in the recent future.
基金financially supported by the National "863" Project (Grant No.:2010AA12220105)the Standard Research of Lunar mapping of Geology and Tectonics (Grant No.:Y2ZZ031000-02) from Institute of Geochemistry, Chinese Academy of Sciences
文摘Based on the CCD images,IIM data and DEM data of China's lunar exploration project (Chang'E-Ⅰ) and related processed and analytic results,an integrated study of regional geology of Sinus Iridum and its adjacent area was conducted,and a series of relevant researches and analyses were carried out,including analysis of impact craters and their extrusive and accumulative materials,division of stratigraphic and tectonic units and classification of rock types,integrated analysis of chronology and lunar evolution history.In consideration of crater's shape features,quantity and preserving status of filling materials,the lunar impact craters can be divided into 7 types and 11 subtypes,and the accumulative materials of craters are divided into 6 types and 9 accumulative groups.According to the content and distribution of TiO2 and image characteristics,the basalts are divided into high-TiO2,medium-TiO2 and low-TiO2 basalts.Discussion was made on division of tectonic units and evolution features in the study area.The geological map of the Sinus Iridum Quadrangle (LQ-4) at a scale of 1∶2.5 M was preliminarily compiled with the ArcGIS system,and the spatial database of the map was established.Related technical specification,procedure and method for lunar geological mapping have been worked out,so as to lay a foundation for the forthcoming geological mapping of the global Moon in China by using the data of Chang'E-Ⅱ and also for comprehensive study and geological mapping of other celestial bodies in the future.
基金supported by the forestry public welfare scientific research project(Grant No.201504303)。
文摘Knowledge on the potential suitability of tree species to the site is very important for forest management planning.Natural forest distribution provides a good reference for afforestation and forest restoration.In this study,we developed species distribution model(SDM)for 16 major tree species with 2,825 permanent sample plots with natural origin from Chinese National Forest Inventory data collected in Jilin Province using the Maxent model.Three types of environmental factors including bioclimate,soil and topography with a total of 33 variables were tested as the input.The values of area under the curve(AUC,one of the receiver operating characteristics of the Maxent model)in the training and test datasets were between 0.784 and 0.968,indicating that the prediction results were quite reliable.The environmental factors affecting the distribution of species were ranked in terms of their importance to the species distribution.Generally,the climatic factors had the greatest contribution,which included mean diurnal range,annual mean temperature,temperature annual range,and iosthermality.But the main environmental factors varied with tree species.Distribution suitability maps under current(1950-2000)and future climate scenarios(CCSM4-RCP 2.6 and RCP 6.0 during 2050)were produced for 16 major tree species in Jilin Province using the model developed.The predicted current and future ranges of habitat suitability of the 16 tree species are likely to be positively and negatively affected by future climate.Seven tree species were found to benefit from future climate including B etula costata,Fraxinus mandshurica,Juglans mandshurica,Phellodendron amurense,Populus ussuriensis,Quercus mongolica and Ulmus pumila;five tree species will experience decline in their suitable habitat including B.platyphylla,Tilia mongolica,Picea asperata,Pinus sylvestris,Pinus koraiensis;and four(Salix koreensis,Abies fabri,Pinus densiflora and Larix olgensis)showed the inconsistency under RCP 2.6 and RCP 6.0 scenarios.The maps of the habitat suitability can be used as a basis for afforestation and forest restoration in northeastern China.The SDMs could be a potential tool for forest management planning.
基金Supported by the Natural Science Foundation of Shandong Province(Y2007E21)the Key Programs for Science and Technology Development of Shandong Province(2006GG2308005)the Soft Science Project of the Shandong Provincial Department of Science and Technology (200624-14)
文摘The three-period (1995, 1998 and 2003) remote sensing images in Jinan City, China are selected. And the information of green land, construction land, woodland and water body is extracted by using the image processing module of remote-sensing software and computerized interpretation module. Both the change table and transfer matrix table of land use area are analyzed by modeling module of remote-sensing software. Then, the Geo-information Tupu is obtained; and the temporal and spatial variation of land use in Jinan City is monitored and analyzed by Geo-information Tupu and transfer matrix. Result shows that land use structure change of Jinan City in the years 1995-1998 shows a transformation from green land to construction land. Area of green land circulating into construction land reaches 62.27 square kilometers, accounting for 25.84% of the initial green land. In the year 1998, areas of woodland and green land are reduced due to the urban expansion of Jinan City. However, with the enhancement of people's awareness of environmental protection, areas of woodland and green land gradually increase in the year 2003, which are still less than those in the year 1995.
基金Projects 40401038 supported by National Natural Science Foundation of China, and 05KJB420133 by Natural Science Foundation for Colleges and Universities in Jiangsu Province
文摘Based on the satellite remote sensing TM/ETM images of Xuzhou city, basic data about land use of the city from 1994 to 2000 are obtained with the neural network classification module of PCI software, and the dynamic con- version matrix of land use is thus calculated. The areas of construction land and water body have increased by 1833.93 hm2 and 804.87 hm2, respectively. On the contrary, the area of cropland has decreased by 3207.24 hm2. The area of cropland converted into construction land makes up 26.84%, and that converted into water body amounts for 8.17% of the total area of cropland in 1994. The variation index of land use degree and the dynamic degree index of land use computed are 1.38 and 57.81%, respectively, which demonstrate that land use in Xuzhou is in a development period and the changes are drastic. The frequency index and importance index of the form in which cropland converted into con- struction land are 29.91% and 68.93% respectively. The results indicate that the change is not only widespread in space but a major form of spatial change of land use in the area.
基金Supported by China Postdoctoral Fund Project (20060391066)Postdoctoral Fund of Heilongjiang Province (LBH-Q06096)
文摘Appraisaling the land-use change degree of urban land objectively, analyzing the reasons, and proposing the countermeasures have important meanings to promote land sustainable development. The article analyzed the dynamic change of land-use ecological footprint in Harbin City from 1996 to 2006. Through the measurement of ecological footprint to assess the social impact and the extent of sustainable land-use. The results showed that the per capita ecological footprint in Harbin had increased year by year, while the per capita ecological carrying capacity had decreased, the per capita ecological deficit was increasing, and land-use in Harbin City was in an overload status. Finally, reasonable land-use proposals were proposed.
文摘[Objectives] The land use change and its influence has been the frontier and hotspot in the research of the surface process of change. The aim of this study was to provide a reasonable scientific basis for the more reasonable use of regional land resources of Bole City by study of land use change and driving force of Bole City.[Methods] Through geometric correction, image mosaic and image registration processing and classification of the remote sensing images of Bole City in 2006, 2011 and 2016, the three images of land use change in land use types (land use change range, dynamic degree and variation degree) were studied, and the natural and social economy in terms of the driving forces of land use change were analyzed.[Results] In the 2006 to 2016 period, cultivated land of Bole City had the land use dynamic growth state, and the average growth rate was 0.26%; and forest land, construction land, water, grassland and unused land showed a decreasing trend, decreased by 0.23%, 0.22%, 0.75%, 3.85% and 1.52%, respectively. In the entire study period, the change of grassland was the biggest, the changes of unused land and water were the second, and the changes of cultivated land, construction land and forest land were lesser.[Conclusions] The main driving factors that effected on land use change of the study area were climate, industrialization, urbanization, social and economic activities, adjustment of agricultural structure and population expansion.
文摘[Objective] The research aimed to study the variation characteristics of climate and its influence on the crop farming in Xintai City.[Method] By using the yearly and monthly average temperature,rainfall,first and last frost dates,frost-free period,sunshine hours,etc.in Xintai City during 1957-2009,the variation characteristics of climate and its influence on the crop farming in Xintai City in recent 53 years were analyzed.[Result] The temperature rose in the fluctuation in Xintai City.The warm winter phenomenon was prominent,and ≥0℃ accumulated temperature increased yearly.In recent 10 years,the first frost postponed,and the last frost advanced.The growth season of crop prolonged.The annual rainfall decreased in the fluctuation,and the annual sunshine hours presented the decrease trend as a whole.For the accumulated temperature increased,and the frost-free period prolonged,the sowing date and farming system of main crops in Xintai City changed.The rising of winter temperature was favorable for the development of industrialized agriculture,such as the warm house booth.The multiple-cropping index improved,and the characteristic planting advantage was prominent.The climate warming made that the planting areas of yellow ginger and day lily enlarged,and the planting boundary moved northward.The sowing dates of wheat and peanut postponed.The sowing date of yellow ginger advanced,and the growth period prolonged.Meanwhile,the climate variation also made that the plant diseases and insect pests,spring frozen injury aggravated in Xintai.The influence of extreme weather induced by the increasing of extreme climate event on the yield and quality of fruit tree was stronger.The planting risks of yellow ginger and day lily increased.[Conclusion] The research provided the scientific basis for promoting the sustainable development of economic society in Xintai.
基金a part of research result of the CLIMA Project,supported by the European Union AsiaLink Programme
文摘Climate change is an inevitable trend,which challenges security of water resources in China,especially in cities.Assessing vulnerability of water resource to climate change in cities has important role for policy makers. The paper constructs a vulnerability function,including exposure,sensitivity and adaptive capacity,according to the vulnerability concept proposed by IPCC,establishes an assessment indicators system of water resources to climate change in cities,and analyzes vulnerability features of Chinese cites based on 655 cities'data in 2006.The vulnerability assessment results show that there are distinctive differences among all the cities,between east,central and west cities,between ordinary,big and mega cities,while there is no statistical significant difference between north and south cities.Based on the research,the paper suggests that strategic emphasis should focus on the central cities and ordinary cities
基金supported by the National Natural Science Foundation of China(41601175,41801362)the Young Backbone Teachers Foundation from Henan Province,China(2018GGJS019,2020GGJS114)+2 种基金the Program for Innovative Research Talent in University of Henan Province,China(20HASTIT017)the 2021 Project of Henan Soft Science Funds,China(212400410250)the 2020 Philosophy and Social Science Planning Project of Henan Province,China(2020BJJ020).
文摘Studies on carbon emissions associated with land use and cover change(LUCC)are key to understanding the impact of human activities on regional sustainability.In this study,we analyzed the temporal and spatial changes in carbon emissions associated with LUCC for production,living,and ecological spaces in Zhengzhou City of China.Landsat remote sensing images were used to classify the land use and land cover(LULC)types in Zhengzhou City in 1988,2001,2009,and 2015.Carbon emissions associated with LUCC were evaluated using a spatial gradient model and the niche mechanism.It was found that during 1988-2015,carbon emissions associated with LUCC in Zhengzhou City increased by 17.1×10^(6) t,while the carbon sink resulted from cultivated land,forests,water bodies,and unused land decreased significantly.Most of the increase in carbon emissions associated with LUCC occurred in the center of the city.The peak carbon emissions were located in the northeastern,southeastern,northwestern,and southwestern regions of Zhengzhou City,and carbon emissions varied considerably in the different spatial gradient rings over time.Among the three spaces,carbon emissions associated with LUCC were mainly affected by the living space.The population size and population urbanization rate were negatively correlated with the ecological space and positively correlated with the production and living spaces.Our results highlight that Zhengzhou City should take the new urbanization path of urban transformation development and ecological civilization construction to ensure the realization of the promised carbon emission reduction targets.
文摘Iain Sinclair, in his Lights Out for the Territory (1997) declared that "walking is the best way to explore and exploit the city". But what exactly is that we are looking for in our contemporary cities? And how can walking contribute in tracing (explore) and therefore mapping (exploit) all those elements or situations that we seek for? Urban space is constantly mutating. Our experience of space as a practiced place changes gradually as the "sterile" private spaces and misleading billboards, the neo-urban surrounding urban environment evolves around us. Amidst walker drifts through the city in search for the peculiar, the original, the intriguing, and the fringe. An urban journey/drifting starts and ends without any predefined plan in mind, while remaining alert and receptive to all incentives given by the practiced urban locus (audio, visual, olfactory, and psychological incentives). Originating from the post-Romantic English writers and the mid-nineteenth century Parisian flaneur, urban drifting has been practiced in multiple ways with different outcomes, but yet highly contributory in the depiction and specific mapping of our urban environment. This paper attempts to investigate the roots of urban drifting, its evolution, and its potential utility as a spatial practice in visual arts, architecture, and mapping.