Rapid urbanization creates complexity,results in dynamic changes in land and environment,and influences the land surface temperature(LST)in fast-developing cities.In this study,we examined the impact of land use/land ...Rapid urbanization creates complexity,results in dynamic changes in land and environment,and influences the land surface temperature(LST)in fast-developing cities.In this study,we examined the impact of land use/land cover(LULC)changes on LST and determined the intensity of urban heat island(UHI)in New Town Kolkata(a smart city),eastern India,from 1991 to 2021 at 10-a intervals using various series of Landsat multi-spectral and thermal bands.This study used the maximum likelihood algorithm for image classification and other methods like the correlation analysis and hotspot analysis(Getis–Ord Gi^(*) method)to examine the impact of LULC changes on urban thermal environment.This study noticed that the area percentage of built-up land increased rapidly from 21.91%to 45.63%during 1991–2021,with a maximum positive change in built-up land and a maximum negative change in sparse vegetation.The mean temperature significantly increased during the study period(1991–2021),from 16.31℃to 22.48℃in winter,29.18℃to 34.61℃in summer,and 19.18℃to 27.11℃in autumn.The result showed that impervious surfaces contribute to higher LST,whereas vegetation helps decrease it.Poor ecological status has been found in built-up land,and excellent ecological status has been found in vegetation and water body.The hot spot and cold spot areas shifted their locations every decade due to random LULC changes.Even after New Town Kolkata became a smart city,high LST has been observed.Overall,this study indicated that urbanization and changes in LULC patterns can influence the urban thermal environment,and appropriate planning is needed to reduce LST.This study can help policy-makers create sustainable smart cities.展开更多
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
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
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
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
[Objective[ The aim was to analyze the characteristics of climate changes in Zhucheng City in Shandong Province from 1961 to 2010. [Method] The temperature and precipitation in Zhucheng City from 1961 to 2010 were cho...[Objective[ The aim was to analyze the characteristics of climate changes in Zhucheng City in Shandong Province from 1961 to 2010. [Method] The temperature and precipitation in Zhucheng City from 1961 to 2010 were chosen to analyze its annual and seasonal changes based on linear trend estimation method. [ Result]The average temperature in recent 50 years rose at a speed of 0.383 ℃/10 a. The mean temperature in each season increased. As the temperature increase span in winter 〉 autumn 〉 spring 〉 summer, the mean precipitation in recent 50 years de- creased at a speed of 18.7 mm/10 a, increased in spring and winter but decreased in summer and autumn. Temperature reduced most distinctly in summer at a speed of 20.9 mm/10 a. The abnormal temperature reduction happened only once in Zhucheng in recent 50 years. Abnormal high temperature happened in seven years, after 1990s. In recent 50 years, only six years had abnormal precipitation and the annual total precipitation decreased, which indicated that the spatial distribution of precipitation was uneven. [ Conclusionl The study provided reference for the increasing accuracy of temperature and of precipitation report.展开更多
Daily and weekly reporting events of climate change and impacts on populations, cultures, economies and politics at local, national, regional and international scales suggest the need to construct databases that will ...Daily and weekly reporting events of climate change and impacts on populations, cultures, economies and politics at local, national, regional and international scales suggest the need to construct databases that will be useful in future scientific inquiry and global human/environmental policies. That need is evident in constructing a geographic or locational knowledge base that examines countries, regions and cities. This study constructs a database on the impacts of climate change using Google Scholar entries for 200 countries and capital cities. A series of maps reveal the vast unevenness in the database, especially between Global North and Global South countries. The discussion explores these sharp differences and suggests future research topics for much-needed global, interdisciplinary and international research.展开更多
Based on the statistical data of temperature and precipitation in Kangding City from 1960 to 2011, the variation characteristics of temperature and precipitation in nearly 50 years were studied. The results showed tha...Based on the statistical data of temperature and precipitation in Kangding City from 1960 to 2011, the variation characteristics of temperature and precipitation in nearly 50 years were studied. The results showed that in Kangding City, average temperature showed an increasing trend in nearly 50 years, which is consistent with global warming. Average temperature in Kangding City was stable from the 1960s to the 1990s but changed obviously in the 2000s. Precipitation in Kangding City tended to increase in nearly 50 years. Spring and summer precipitation increased synchronously, and autumn precipitation was five times more than winter precipitation.展开更多
By analyzing the climate records of Kunming from 1957 to 2016, Kunming’s average temperature has been found to be increasing in recent 65 years. The key problem lies in the temperature rise in recent 10 or more years...By analyzing the climate records of Kunming from 1957 to 2016, Kunming’s average temperature has been found to be increasing in recent 65 years. The key problem lies in the temperature rise in recent 10 or more years by 0.4 ℃/10a and the annual range decrease at the same time, represented as the elevation of the lowest temperature and increasingly warmer winter in Kunming. With the warming climate, the precipitation has suffered a prominent fall, by 18.05 mm/a in the past 14 years. The relative humidity is in direct proportion to the precipitation, which explains less water and drier climate in Kunming. With “One increase and two decreases” of the three key climate indexes changes in Kunming in the past 65 years, this paper analyzed the necessity and general situation of the sponge city construction in the city, proposed the overall planning of sponge city construction at the macro level, selected the sponge technology based on the urban construction land types, and planned the regulation facilities based on the catchment area and green space structure. Moreover, the paper explored the sponge city planning at the meso level and the sponge city eco-engineering technology at the micro level.展开更多
Based on the observation data of temperature in Chengxian meteorological station( the climate representative station of Longnan City,Gansu Province) during 1961-2014,the annual,seasonal and monthly changes of temper...Based on the observation data of temperature in Chengxian meteorological station( the climate representative station of Longnan City,Gansu Province) during 1961-2014,the annual,seasonal and monthly changes of temperature were analyzed,and the abrupt changes in relevant variables were tested using the cumulative anomaly method. The results showed that annual average temperature in Chengxian County increased by 0. 138 ℃/10 a in the past 54 years. There was an obvious sudden change in annual average temperature around 1996. The annual average temperature showed a downward trend before 1996 and an upward trend after 1996. Average temperature in spring,summer,autumn and winter increased by 0. 113,0. 028,0. 157 and 0. 259 ℃/10 a respectively. The fluctuation of average temperature in spring and winter was the largest,followed by summer,while the fluctuation was the smallest in autumn. There were certain differences between various seasons in terms of the years with sudden changes in average temperature,which was not consistent with the years with the sudden changes in annual average temperature. The changing rate of monthly average temperature was the largest in February( up to 0. 412 ℃/10 a),followed by March,April and November,but it was the smallest in May( only 0. 005 ℃/10 a). The maximum of monthly average temperature appeared mostly in the 21 stcentury,while the minimum appeared in the 20 thcentury.展开更多
Based on meteorological observation data of temperature and precipitation in Yanshi City from 1961 to 2010, annual and interdecadal variations of annual average temperature, annual average maximum temperature, annual ...Based on meteorological observation data of temperature and precipitation in Yanshi City from 1961 to 2010, annual and interdecadal variations of annual average temperature, annual average maximum temperature, annual average minimum temperature, and annual average pre- cipitation in Yanshi City in recent 50 years were analyzed, and then M-K test of changing trend of annual average temperature was conducted. The results showed that from 1961 to 2010, annual average temperature, annual average maximum temperature and annual average minimum tempera- ture showed a significantly increasing trend in Yanshi City, rising by 0.30, 0.20 and 0.50 ~(3/10 a respectively. Annual average temperature was the lowest in the 1970s and the highest in 2000 -2010. There was a sudden change in annual average temperature in 1995. In the 50 years, annual av- erage precipitation in Yanshi City increased by 1.8 mm/10 a, but the increase was not significant. The minimum of annual average precipitation 511.3 mm appeared in the 1960s, while the maximum 553.2 mm appeared in 2000 -2010.展开更多
According to Anhui Statistical Yearbook( 2003-2012) and the second national land survey data,this article analyzes the current situation of land use and the dynamic change in the total arable land in Tongling City. On...According to Anhui Statistical Yearbook( 2003-2012) and the second national land survey data,this article analyzes the current situation of land use and the dynamic change in the total arable land in Tongling City. On the basis of this,using grey relational analysis,this article analyzes the driving forces for arable land changes in Tongling City. Studies show that population growth,the improvement of level of urbanization and the rapid development of the economy are the main driving forces for arable land changes. Based on the findings,the strategies are put forth in order to ensure the dynamic balance of total arable land.展开更多
基金the University Grants Commission,New Delhi,India,for providing financial support in the form of the Junior Research Fellowship。
文摘Rapid urbanization creates complexity,results in dynamic changes in land and environment,and influences the land surface temperature(LST)in fast-developing cities.In this study,we examined the impact of land use/land cover(LULC)changes on LST and determined the intensity of urban heat island(UHI)in New Town Kolkata(a smart city),eastern India,from 1991 to 2021 at 10-a intervals using various series of Landsat multi-spectral and thermal bands.This study used the maximum likelihood algorithm for image classification and other methods like the correlation analysis and hotspot analysis(Getis–Ord Gi^(*) method)to examine the impact of LULC changes on urban thermal environment.This study noticed that the area percentage of built-up land increased rapidly from 21.91%to 45.63%during 1991–2021,with a maximum positive change in built-up land and a maximum negative change in sparse vegetation.The mean temperature significantly increased during the study period(1991–2021),from 16.31℃to 22.48℃in winter,29.18℃to 34.61℃in summer,and 19.18℃to 27.11℃in autumn.The result showed that impervious surfaces contribute to higher LST,whereas vegetation helps decrease it.Poor ecological status has been found in built-up land,and excellent ecological status has been found in vegetation and water body.The hot spot and cold spot areas shifted their locations every decade due to random LULC changes.Even after New Town Kolkata became a smart city,high LST has been observed.Overall,this study indicated that urbanization and changes in LULC patterns can influence the urban thermal environment,and appropriate planning is needed to reduce LST.This study can help policy-makers create sustainable smart cities.
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.
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.
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[Objective[ The aim was to analyze the characteristics of climate changes in Zhucheng City in Shandong Province from 1961 to 2010. [Method] The temperature and precipitation in Zhucheng City from 1961 to 2010 were chosen to analyze its annual and seasonal changes based on linear trend estimation method. [ Result]The average temperature in recent 50 years rose at a speed of 0.383 ℃/10 a. The mean temperature in each season increased. As the temperature increase span in winter 〉 autumn 〉 spring 〉 summer, the mean precipitation in recent 50 years de- creased at a speed of 18.7 mm/10 a, increased in spring and winter but decreased in summer and autumn. Temperature reduced most distinctly in summer at a speed of 20.9 mm/10 a. The abnormal temperature reduction happened only once in Zhucheng in recent 50 years. Abnormal high temperature happened in seven years, after 1990s. In recent 50 years, only six years had abnormal precipitation and the annual total precipitation decreased, which indicated that the spatial distribution of precipitation was uneven. [ Conclusionl The study provided reference for the increasing accuracy of temperature and of precipitation report.
文摘Daily and weekly reporting events of climate change and impacts on populations, cultures, economies and politics at local, national, regional and international scales suggest the need to construct databases that will be useful in future scientific inquiry and global human/environmental policies. That need is evident in constructing a geographic or locational knowledge base that examines countries, regions and cities. This study constructs a database on the impacts of climate change using Google Scholar entries for 200 countries and capital cities. A series of maps reveal the vast unevenness in the database, especially between Global North and Global South countries. The discussion explores these sharp differences and suggests future research topics for much-needed global, interdisciplinary and international research.
基金Supported by the Project of Education Department of Sichuan Province,China(16ZB0365)Project of Sichuan Minzu College(XYZB18041SB)
文摘Based on the statistical data of temperature and precipitation in Kangding City from 1960 to 2011, the variation characteristics of temperature and precipitation in nearly 50 years were studied. The results showed that in Kangding City, average temperature showed an increasing trend in nearly 50 years, which is consistent with global warming. Average temperature in Kangding City was stable from the 1960s to the 1990s but changed obviously in the 2000s. Precipitation in Kangding City tended to increase in nearly 50 years. Spring and summer precipitation increased synchronously, and autumn precipitation was five times more than winter precipitation.
基金Sponsored by Scientific Research Foundation of Yunan Provincial Department of Yunnan(2018JS772)
文摘By analyzing the climate records of Kunming from 1957 to 2016, Kunming’s average temperature has been found to be increasing in recent 65 years. The key problem lies in the temperature rise in recent 10 or more years by 0.4 ℃/10a and the annual range decrease at the same time, represented as the elevation of the lowest temperature and increasingly warmer winter in Kunming. With the warming climate, the precipitation has suffered a prominent fall, by 18.05 mm/a in the past 14 years. The relative humidity is in direct proportion to the precipitation, which explains less water and drier climate in Kunming. With “One increase and two decreases” of the three key climate indexes changes in Kunming in the past 65 years, this paper analyzed the necessity and general situation of the sponge city construction in the city, proposed the overall planning of sponge city construction at the macro level, selected the sponge technology based on the urban construction land types, and planned the regulation facilities based on the catchment area and green space structure. Moreover, the paper explored the sponge city planning at the meso level and the sponge city eco-engineering technology at the micro level.
基金Supported by the Project of Research on Risk Division of Characteristic Agricultural Meteorological Disasters and Climatic Regionalization in Longnan Mountainous Areas(2013-20)
文摘Based on the observation data of temperature in Chengxian meteorological station( the climate representative station of Longnan City,Gansu Province) during 1961-2014,the annual,seasonal and monthly changes of temperature were analyzed,and the abrupt changes in relevant variables were tested using the cumulative anomaly method. The results showed that annual average temperature in Chengxian County increased by 0. 138 ℃/10 a in the past 54 years. There was an obvious sudden change in annual average temperature around 1996. The annual average temperature showed a downward trend before 1996 and an upward trend after 1996. Average temperature in spring,summer,autumn and winter increased by 0. 113,0. 028,0. 157 and 0. 259 ℃/10 a respectively. The fluctuation of average temperature in spring and winter was the largest,followed by summer,while the fluctuation was the smallest in autumn. There were certain differences between various seasons in terms of the years with sudden changes in average temperature,which was not consistent with the years with the sudden changes in annual average temperature. The changing rate of monthly average temperature was the largest in February( up to 0. 412 ℃/10 a),followed by March,April and November,but it was the smallest in May( only 0. 005 ℃/10 a). The maximum of monthly average temperature appeared mostly in the 21 stcentury,while the minimum appeared in the 20 thcentury.
文摘Based on meteorological observation data of temperature and precipitation in Yanshi City from 1961 to 2010, annual and interdecadal variations of annual average temperature, annual average maximum temperature, annual average minimum temperature, and annual average pre- cipitation in Yanshi City in recent 50 years were analyzed, and then M-K test of changing trend of annual average temperature was conducted. The results showed that from 1961 to 2010, annual average temperature, annual average maximum temperature and annual average minimum tempera- ture showed a significantly increasing trend in Yanshi City, rising by 0.30, 0.20 and 0.50 ~(3/10 a respectively. Annual average temperature was the lowest in the 1970s and the highest in 2000 -2010. There was a sudden change in annual average temperature in 1995. In the 50 years, annual av- erage precipitation in Yanshi City increased by 1.8 mm/10 a, but the increase was not significant. The minimum of annual average precipitation 511.3 mm appeared in the 1960s, while the maximum 553.2 mm appeared in 2000 -2010.
文摘According to Anhui Statistical Yearbook( 2003-2012) and the second national land survey data,this article analyzes the current situation of land use and the dynamic change in the total arable land in Tongling City. On the basis of this,using grey relational analysis,this article analyzes the driving forces for arable land changes in Tongling City. Studies show that population growth,the improvement of level of urbanization and the rapid development of the economy are the main driving forces for arable land changes. Based on the findings,the strategies are put forth in order to ensure the dynamic balance of total arable land.