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Copyright of Remote Sensing for Natural Resources is the property of Remote Sensing for Natural Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Globalization and informatization have exerted far-reaching impacts on the spatial connection and development of urban systems. This study, concerning the network of an urban system based on the space of flows, supplements the insufficiency on the micro-level in macro-urban network research. Taking Nanjing as an example, this study explores the characteristics of the network of the urban system from the perspective of people flow, refining the granularity of the analysis to the township- and street-level spatial units using mobile phone data. The findings are as follows: (1) There is a multicenter layered network pattern, with the main urban area being the core of the network, while Dongshan Street and Moling Street, as secondary centers, form a joint development pattern with the main urban area. (2) The spatial differentiation is significant. The spatial heterogeneity of "centralization in the central region, delayering in the north, and hierarchization in the south" is obvious. The net people inflow nodes are mainly concentrated in the main urban area and its surroundings, while the net outflow nodes are mostly located on the edge of the city. Moreover, the nodes to the south of Yangtze River are advantageous in urban resource control. (3) The phenomenon of "double shadow circle" appears in the ring of the main city and the ring of the municipal area. Moreover, the northern district experiences a serious outflow of population. (4) The effect of policy intervention is beginning to show. Improved levels of development of street and township units such as Jiangbei New District show the positive influence of national strategy on regional development. [ABSTRACT FROM AUTHOR]

Amid the escalating conflicts between urban demography, resource availability, and environmental constraints, there is an accelerating demand for emergency medical services prompted by a spectrum of factors including diseases, natural calamities, and unforeseen events. This growth is further accentuated by an imbalance in the allocation of emergency facilities, amplifying public anxiety and underscoring the urgent necessity for scientifically informed optimization of pre-hospital emergency facilities. To this end, the present study articulates specific optimization goals for facility deployment and introduces a nuanced set coverage optimization model that integrates spatiotemporal determinants of emergency service requirements. The model is fortified with a constellation of constraints, including spatial constraint, temporal constraint, and coverage constraint. For spatial constraints, we use the Monte Carlo simulation to predict the spatial distribution of emergency demands. Temporal constraints involve determining the actual travel time matrix from predicted demand points to candidate sites. Coverage constraints specify the effective demand coverage rate. This study uses Nanjing as a case example, utilizing multisource big data, including ambulance GPS logs from June 2016 to May 2017, Amap traffic congestion indicators, and survey data on existing emergency facilities in Nanjing City. By preprocessing and analyzing the existing data, this study thoroughly investigates the spatiotemporal distribution of emergency demands and the impact of traffic congestion on emergency service effectiveness. Consequently, the model incorporates constraints that ensure, under the specified planning and actual traffic conditions, 95 % of the simulated emergency demands can be met within an 8-minute on-route time. Locations for pre-hospital emergency stations are optimized using a genetic algorithm, achieving the best solution at the 120th iteration. Verification confirms 134 optimal sites; after excluding 52 existing sites, 82 potential sites are identified. The new layout plan has reduced Nanjing’s average emergency response time from 18.6 min to 12 min. Additionally, under peak and average traffic conditions, emergency demand coverage rates improved from 76.92 % and 83.18 % at 15 min to 95.61 % and 98.10 % at 12 min, respectively. These results demonstrate that the new layout significantly enhances practical application effectiveness. The approach presented in this paper addresses the previously overlooked randomness of emergency incidents and traffic conditions, offering innovative strategies for improving the efficiency and effectiveness of emergency station planning and site selection models.

Copyright of Geology & Exploration is the property of Geology & Exploration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Globalization and informatization have exerted far-reaching impacts on the spatial connection and development of urban systems. This study, concerning the network of an urban system based on the space of flows, supplements the insufficiency on the micro-level in macro-urban network research. Taking Nanjing as an example, this study explores the characteristics of the network of the urban system from the perspective of people flow, refining the granularity of the analysis to the township- and street-level spatial units using mobile phone data. The findings are as follows: (1) There is a multicenter layered network pattern, with the main urban area being the core of the network, while Dongshan Street and Moling Street, as secondary centers, form a joint development pattern with the main urban area. (2) The spatial differentiation is significant. The spatial heterogeneity of “centralization in the central region, delayering in the north, and hierarchization in the south” is obvious. The net people inflow nodes are mainly concentrated in the main urban area and its surroundings, while the net outflow nodes are mostly located on the edge of the city. Moreover, the nodes to the south of Yangtze River are advantageous in urban resource control. (3) The phenomenon of “double shadow circle” appears in the ring of the main city and the ring of the municipal area. Moreover, the northern district experiences a serious outflow of population. (4) The effect of policy intervention is beginning to show. Improved levels of development of street and township units such as Jiangbei New District show the positive influence of national strategy on regional development.

Night-time light data (NTL) have been extensively utilized to map urban fringe areas, but to date, there has not been a comprehensive evaluation of the existing spatial clustering methods for delineating the urban fringe using different types of night-time light data. Therefore, we first selected three popular sources of night-time light data (i.e., NPP/VIIRS, Luojia 1-01, and NASA's Black Marble) to identify the urban fringe. The recognition of spatial mutations across the urban–rural gradient was conducted based on changes in night light intensity using a spatial continuous wavelet transform model. Then, we employed three representative dual spatial clustering approaches (i.e., MK-Means, DBSC, and DSC) for extracting urban fringe areas using different NTL. By using dual spatial clustering, the spatial patterns of the mutation points were effectively transformed into homogeneous spatially adjacent clusters, enabling the measurement of similarity between mutation points. Taking Nanjing city, one of China's megacities, as the study area, we found that (1) Compared with the fragmented and concentrated results obtained from the Luojia 1-01, NASA's Black Marble and NPP/VIIRS data can effectively capture the abrupt change of urban fringes with NTL variations; (2) DSC provided a reliable approach for accurately extracting urban fringe areas using NASA's Black Marble data. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ecology & Rural Environment is the property of Journal of Ecology & Rural Environment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The London plane (Platanus × acerifolia (Aiton) Willd.) street tree is a symbolic tree species in Nanjing City, which is known as the "city card". However, accidents such as street trees falling over cars, affecting traffic, and hurting people have seriously affected the daily lives of citizens. Thus, it is of vital significance to accurately assess the potential for tree failure in London plane street trees in Nanjing City. This study comprehensively considers the growth condition of London plane street trees and their impact on traffic, establishes a scientific street tree failure assessment scheme that contains eight characteristics, creates a tree failure assessment database by thoroughly collecting data on trees, and develops a tree failure assessment model based on factor analysis and k-means clustering. The assessment results show that street trees that pose a high or medium potential for failure are present in proportions of 4.47% and 34.85%, respectively, and are mostly found in Gulou District, Xuanwu District, and Qinhuai District. The average tree failure score of London plane street trees on Changjiang Road in Xuanwu District is the highest, while the road with the lowest tree failure score is Mufu East Road in Gulou District. The results will provide a scientific basis for the maintenance of London plane street trees in Nanjing City and have reference significance for other street tree failure assessment studies. [ABSTRACT FROM AUTHOR]

Exact land cover (LC) map is essential information for understanding the development of human societies and studying the impacts of climate and environmental change. To fulfill this requirement, an optimal parameter of Random Forest (RF) for LC classification with suitable data type and dataset on Google Earth Engine (GEE) was investigated. The research objectives were 1) to examine optimum parameters of RF for LC classification at local scale 2) to classify LC data and assess accuracy in model area (Hefei City), 3) to identify a suitable data type and dataset for LC classification and 4) to validate optimum parameters of RF for LC classification with a suitable data type and dataset in test area (Nanjing City). This study suggests that the suitable data types for LC classification were Sentinel-2 data with auxiliary data. Meanwhile, the suitable dataset for LC classification was monthly and seasonal medians of Sentinel-2, elevation, and nighttime light data. The appropriate values of the number of trees, the variable per split, and the bag fraction for RF were 800, 22, and 0.9, respectively. The overall accuracy (OA) and Kappa index of LC in model area (Hefei City) with suitable dataset was 93.17% and 0.9102. In the meantime, the OA and Kappa index of LC in test area (Nanjing City) was 92.38% and 0.8914. Thus, the developed research methodology can be applied to update LC map where LC changes quickly occur.

The scientific assessment of ecosystem service value (ESV) and landscape ecological risk (LER) is important for ecological security and sustainable development. However, existing studies often separate ESV and LER for a single evaluation, and the single evaluation is limited in guiding ecological conservation. Therefore, proposing an evaluation framework that integrates ESV and LER is urgent. Taking Nanjing City as an example, this study evaluated LER based on the risk evaluation cell and introduced it into ESV evaluation. Then, the influence of land use/land cover change on LER and ESV from 2000 to 2020 was analyzed. The results showed that built-up land and water body/wetland increased by 881.96 km2 and 41.41 km2, and farmland and forest land decreased by 875.46 km2 and 55.83 km2 from 2000 to 2020. The LER was low in the middle and high in the north and south. From 2000 to 2010, the LER increased from 0.67 to 0.68, and it then decreased to 0.61 in 2020. Medium-low risk regions decreased during 2000–2010, and low-risk regions increased and medium-high risk regions decreased during 2010–2020. The ESV increased by 0.77 billion United States dollars (USD) during 2000–2010 but decreased by 0.40 billion USD during 2010–2020. Under the impact of LER, the ESV per unit area of the farmland, forest land, and water body decreased during 2000–2020. The ESV of the water body dominated the total ESV and had an important influence on the change in total ESV. The ESV in Nanjing City during 2000–2020 mainly showed High-High autocorrelation and a few Low-High autocorrelations. Ecological restoration programs increased ESV during 2000–2010, but rapid urbanization reduced ESV during 2010–2020. Integrating social, economic, and ecological resources is necessary to realize the coordinated development of the economy and ecology. The results can provide an important reference for landscape planning and ecosystem management.

As a designated national low-carbon pilot city, Nanjing faces the challenge of reducing energy consumption and carbon emissions while experiencing rapid economic growth. This study developed a localized Long-range Energy Alternatives Planning System (LEAP) model specifically for Nanjing and constructed four different development scenarios. By utilizing the Log Mean Divisia Index (LMDI) decomposition, the Tapio decoupling elasticity coefficient, and comparing the emission reduction effects of individual measures and their cross-elasticity of carbon reduction, this study investigated the key factors and their carbon reduction path characteristics in Nanjing toward its carbon peak target by 2030. The results indicate that: (i) Nanjing could reach its peak carbon target of about 3.48 million tons by 2025 if carbon reduction measures are strengthened; (ii) The main elements influencing Nanjing's carbon peak include controlling industrial energy consumption, restructuring the industry, promoting the construction of a new power system, and developing green transportation; (iii) Controlling industrial energy consumption and changing industrial structure have a greater impact on reducing carbon emissions than other measures, and both have a synergistic effect. Therefore, Nanjing should prioritize these two strategies as the most effective methods to reduce carbon emissions. Additionally, to slow down the growth of urban carbon emissions, policies aimed at reducing the energy intensity and carbon intensity of energy consumption should be formulated. For instance, the integration and innovation of green industries within the city region, such as new energy vehicles, new energy materials, and big data, should be accelerated, and the proportion of clean energy consumption in urban areas should be increased. The LEAP (Nanjing) model has successfully explored Nanjing's low-carbon pathway and provided policy guidance for the optimal transformation of industrial cities and early carbon peaking. [ABSTRACT FROM AUTHOR]

In this study, the water-soluble inorganic ions (WSIIs) composition of fine particulate matter (PM2.5) was measured in the northern Nanjing city from 2015 to 2021. NH4+, NO3− and SO42− concentrations dominated in total WSIIs (Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3− and SO42−), accounting for 87.8%. The nitrate with highest average concentration among all ions was 11.0 μg·m−3. Total WSIIs concentrations were higher in winter and lower in summer, with the highest levels in December (45.6 μg·m−3) and the lowest levels in August (15.1 μg·m−3). NO3−/SO42− was higher than 1, indicating the important contribution of mobile sources. The aerosols exhibited a weak acidic by the molar ratio of water-soluble anions and cations. Positive matrix factorization (PMF) analysis results showed that secondary nitrate and sulfate were the major pollution sources in December 2016 and 2020. The contribution of secondary nitrate in 2020 increased by 47.6% compared to 2016, while that of secondary sulfate decreased by 42.4%. The potential source contribution results demonstrated that for secondary aerosol concentrations, the contribution of regional transport from north of Anhui increased, while the contribution of local emissions decreased. The results from this study could contribute to the better prevention and control of regional air pollution in the future. [ABSTRACT FROM AUTHOR]

Night-time light data (NTL) have been extensively utilized to map urban fringe areas, but to date, there has not been a comprehensive evaluation of the existing spatial clustering methods for delineating the urban fringe using different types of night-time light data. Therefore, we first selected three popular sources of night-time light data (i.e., NPP/VIIRS, Luojia 1-01, and NASA’s Black Marble) to identify the urban fringe. The recognition of spatial mutations across the urban–rural gradient was conducted based on changes in night light intensity using a spatial continuous wavelet transform model. Then, we employed three representative dual spatial clustering approaches (i.e., MK-Means, DBSC, and DSC) for extracting urban fringe areas using different NTL. By using dual spatial clustering, the spatial patterns of the mutation points were effectively transformed into homogeneous spatially adjacent clusters, enabling the measurement of similarity between mutation points. Taking Nanjing city, one of China’s megacities, as the study area, we found that (1) Compared with the fragmented and concentrated results obtained from the Luojia 1-01, NASA’s Black Marble and NPP/VIIRS data can effectively capture the abrupt change of urban fringes with NTL variations; (2) DSC provided a reliable approach for accurately extracting urban fringe areas using NASA’s Black Marble data.

To obtain the distribution of nighttime light poUution on a city scale, this study monitors the nighttime light poUution in Nanjing City based on Lucim 1-01 nighttime light remote sensing images. The apparent radiance of the remote sensing images was converted into the surface incident luminance according to surface reflectance and building coverage ratio. Based on this and the iiluminance values observed in the field, various empirical models were established to calculate the nighttime iiluminance of Nanjing City. FinaHy, the distribution of nighttime light poUution in Nanjing City was analyzed according to the calculated nighttime iiluminance. The results show that the third - order polynomial regreesion model had the highest accuracy, with a determinatisn coefficient of 0. 87 and a mean absolute emor ( MAE) of 4. 71 lx. The nighttime iiluminance in Nanjing City varied in the range of 0 -55 lx, with obvious spatial distribution diSferences. In general, the areas with high iiluminance were mainly concentrated in the main urban area and the iiluminance showed a decreasing trend from the main urban area to the surrounding area. Light poUution was the most serious in Gulou and Qinhuai districts, where light poUution covered more than 70% in terms of area. The light poUution in the suburb was relatively weak, and the three districts with the weakest light poUution included Gaochun, Lishui, and Liuhe districts succeesively, where light poUution covered lees than 4% in terms of area. Some areas in Nanjing City showed extremely high iiluminance ( > 30 lx), including large shopping malls, large factories, traffic hubs roads and some residential areas. It should be noted that there are many residential areas near these places except for traffic hubs and large factories. This study explored a method of monitoring urban light poUution at night based on Luoiia 1-01 remote sensing data. It will provide data support for the light poUution control and management in Nanjing City and a scientific reference for the light poUution monitoring in other areas. [ABSTRACT FROM AUTHOR]

With the rapid development of China's industrial economy, heavy metals continue to accumulate in the environment, which has created serious threats for the ecological environment and human health. This study collected 50 surface soil samples in Nanjing, a typical developed city in China, and the contents of Al, Ca, Fe, Mg, Mn, Ni, Ti, Cd, Cr, Cu, Pb, and Zn in the samples were determined. Combined with the ecological risk index and the health risk assessment model, the risk of soil heavy metals in Nanjing was comprehensively evaluated. The results show that the variation coefficients of Pb and Cu are distinctly large, and these elements are all slightly polluting. Children are at a high risk of exposure in various ways, among which Pb and Cu elements have a high risk of causing non-carcinogenic issues. The results of the correlation analysis showed that the content changes of Pb, Zn, and Cu had extremely significant correlations, indicating that they may have the same source. The results of the principal component analysis showed that industrial sources in Nanjing contributed the most heavy metals, reaching 34.4%. The second largest source was from parent material and fertilizer, which contributed 32.3% and 19.6%, respectively. The sources with the lowest contributions were from weathering and deposition, which reached 13.7%. The results of this study will provide guidance and reference for risk-source analysis, early warning, and management of soil heavy metals in developed cities. [ABSTRACT FROM AUTHOR]

In this study, the water-soluble inorganic ions (WSIIs) composition of fine particulate matter (PM2.5) was measured in the northern Nanjing city from 2015 to 2021. NH4+, NO3− and SO42− concentrations dominated in total WSIIs (Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3− and SO42−), accounting for 87.8%. The nitrate with highest average concentration among all ions was 11.0 μg·m−3. Total WSIIs concentrations were higher in winter and lower in summer, with the highest levels in December (45.6 μg·m−3) and the lowest levels in August (15.1 μg·m−3). NO3−/SO42− was higher than 1, indicating the important contribution of mobile sources. The aerosols exhibited a weak acidic by the molar ratio of water-soluble anions and cations. Positive matrix factorization (PMF) analysis results showed that secondary nitrate and sulfate were the major pollution sources in December 2016 and 2020. The contribution of secondary nitrate in 2020 increased by 47.6% compared to 2016, while that of secondary sulfate decreased by 42.4%. The potential source contribution results demonstrated that for secondary aerosol concentrations, the contribution of regional transport from north of Anhui increased, while the contribution of local emissions decreased. The results from this study could contribute to the better prevention and control of regional air pollution in the future.

Objectives: Based on taxi movement trajectories, urban traffic operating conditions can be analyzed. At present, the relevant research mainly focuses on the investigation of traffic origin and destination points and the extraction of traffic hotspots, but seldom analyzes the interaction between traffic hotspots. We focus on exploring the temporal and spatial patterns of urban traffic hotspots, with the purpose of providing a scientific basis for traffic management departments for traffic management in different periods and sections.Methods: We take the main urban city of Nanjing City as the research area, and use taxi GPS data in 2015, 2016, and 2017 for experiments. Firstly, the effective trajectory flow is extracted from the taxi GPS data through the local anomaly test method. Secondly, based on the GeoJSON geocoding to realize map matching, the Pathlet method is used to process the trajectory flow into a sequence which can be optimally solved by dynamic programming. Finally, based on the standard for evaluation of urban traffic operation status, the macroscopic fundamental diagram model is constructed according to the relationship be‑ tween traffic flow, speed and density in the road network, and the evaluation index is established by combining travel time ratio and the delay time ratio.Results: (1) Judging from the average of the traffic operation indicators, the main urban area of Nanjing is the most congested in the morning and evening rush hours, and the traffic is smooth in the early morning hours, and the traffic hotspots are more active on working days than on rest days. (2) Judging from the traffic operation indicators of the nine different nodes, the traffic congestion near the parking lot and office building nodes is relatively increased on weekdays, and the traffic congestion near the nodes of shopping malls and residential quarters is relatively increased on the rest days.(3) Judging from the perspective of spatial distribution of traffic hotspots in five representative periods, traffic hotspots mostly appear near intersections and ramps, and there are more interactions between main roads and express roads, but between townships and village roads and county roads. There is less interaction. (4) Judging from the perspective of the temporal and spatial patterns of traffic hotspots near the school during the morning rush hour, the temporal and spatial interaction characteristics of traffic hotspots are significant in areas with high node coverage, while the spatial distribution characteristics of traffic hotspots change unclearly with time in areas with low node coverage.Conclusions: Urban traffic hotspots show significant differences in time and space distribution characteristics, and their spatiotemporal interactions be‑ come stronger with time and space aggregation, which has a significant positive correlation. [ABSTRACT FROM AUTHOR]

Copyright of East China Geology / Huadong dizhi is the property of Editorial Department of East China Geology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Agriculture has great significance for the national food, resource, and ecological security, closely relating to the life stability and health of every resident. The cultivated land is constantly occupied by urban construction as the urbanization rapidly increases. The transfer of a large number of rural labor force and the change of food consumption structure have caused great challenge on the production and supply of vegetable food in China. The former Ministry of Agriculture has launched the Vegetable Basket Project in 1988, to solve the tight supply of agricultural and sideline products. A Vegetable Basket Project planning aims to transform and expand the vegetable greenhouse base, with emphasis on strong resistance to natural disasters, stable and high yield, further to realize the balance of seasonal production and perennial consumption of vegetables. In remote sensing interpretation of Nanjing City from 1995 to 2017, the cultivated farmlands were retreating from the urban areas, and the vegetable producing areas were shifting from the central to the outer suburbs, while the greenhouse areas were ever-increasing, as the main source of urban construction and expansion. It is necessary to evaluate the Vegetable Basket Policy on the specific change of greenhouse areas in rapid urbanization. In this study, a field survey of farmers and policy analysis were carried out in six main greenhouse planting areas (Pukou, Lishui, Gaochun, Jiangning, Qixia and Liuhe District) in Nanjing, China. A Tobit model was used to quantify the impact of Vegetable Basket Project on greenhouse expansion. The variables included policy factors (whether it was a vegetable production base and the distance from vegetable production base), location factors (the distance from the vegetable market and the distance from the nearest road) and terrain factor (the slope). The results showed that: 1) The Vegetable Basket Project was an important driving force of greenhouse expansion in Nanjing in recent 20 years, thereby to effectively promote the process of suburban agricultural facilities; 2) In the Vegetable Basket Policy, the most significant impact factor was the planning and construction of vegetable production base on the change of greenhouse areas; 3) The location factors, such as market and traffic, were important impacts on the area of suburban greenhouses. The change proportion of greenhouse areas decreased with the increase of the distance from the vegetable market and roads; 4) There was a regional difference in the change of greenhouse areas. Both market accessibility and traffic convenience played a positive role in the expansion of greenhouses in each district. The policy factors were dominated in the different changes in greenhouse areas. 5) In qualitative analysis, it was found that the Vegetable Basket Policy, together with agricultural, farmers' and farmland policy, promoted the transformation of farmland greenhouses in the suburbs of big cities. [ABSTRACT FROM AUTHOR]

Copyright of Landscape Architecture Frontiers is the property of Higher Education Press Limited Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

River crab industry plays an important role in agriculture in Nanjing City, Jiangsu Province. In recent years, with the renewal of breeding mode, the breeding of improved varieties and the construction of brand, the river crab industry has made great progress. Taking the aquaculture enterprises and major breeding farmers in the main producing areas of river crab as the main research object, this paper makes a survey on the river crab industry in Nanjing. Based on fishery statistical data and comparison with advanced areas, this paper makes an indepth analysis on the current situation, existing problems and development measures of Nanjing river crab industry, and it is recommended to make full use of external opportunities and give full play to its own advantages, in order to make Nanjing river crab industry develop healthily and rapidly. [ABSTRACT FROM AUTHOR]

In order to solve the problem of power supply shortage in certain region of Nanjing city, a high-voltage direct current (HVDC) flexible transmission project needs to be constructed. It could be the first project with ±380 kV DC and real bipolar connection in the world. Two new converter stations will be built with 1500 MW transmission capacity. The system design scheme has been proposed including the main connection mode of converter stations, the operation mode, the control strategy, parameters design for main circuit and determination of converter station's power operation range. This technical solution can provide complete design method for future HVDC flexible transmission project, which is of great significance to the development and engineering application of the HVDC flexible technology in China.

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights • Built-up land occupy cropland is the main land use type change pattern. • The initial core city and the peripheral area shows the most obvious land use type change. • NDVI and NEP were both under weak increasing trend on the whole. • Woodland shrinking contributed the most to carbon storage loss. • Land use intensities and anthropogenic carbon emissions kept increasing. Abstract Land use change can greatly affect the carbon balance for both terrestrial ecosystems and anthropogenic carbon emissions. However, "physical-social" integrated carbon balance examinations and the link to multiangle land use change analysis are still lacking. Based on land use data, field observations, climate data, and socioeconomic data, this study performed a comprehensive analysis of land use change from the aspects of land use type, land cover and land use intensity and examined the effect on carbon storage, the net ecosystem productivity (NEP) and energy consumption-related carbon emissions. Finally, this study proposed multiangle land use strategies for low-carbon development. The results show that built-up land occupation of cropland was the main land use type change pattern in Nanjing City. The period of 2005–2010 presented the most obvious land use type change. Between 2000–2015, vegetation carbon storage loss reached 8.21×104 t, with woodland shrinkage contributing the most. The initial core city and the peripheral area show the most obvious land use type changes, with decreases in the Normalized Difference Vegetation Index (NDVI) and NEP. For all of Nanjing City, the NDVI followed a weak increasing trend from 2000 to 2015, and the NEP also exhibited a weak increasing trend for areas without built-up land and water. Spatially, the NDVI and NEP present similar changing trends for most grids. Land use intensities were continuously increasing, and energy-related carbon emissions increased from 4389.35×104 t in 2000 to 10145.09×104 t in 2015, with the industry sector contributing more than 80% of the total carbon emissions. In total, NEP accumulation can offset 2% of energy-related carbon emissions. Low-carbon land management should be strengthened from multi-land use aspects, including urban expansion control, ecological land protection, and land use efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Research of Environmental Sciences is the property of Research of Environmental Sciences Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve the problem of power supply shortage in certain region of Nanjing city, a high-voltage direct current (HVDC) flexible transmission project needs to be constructed. It could be the first project with ±380 kV DC and real bipolar connection in the world. Two new converter stations will be built with 1500 MW transmission capacity. The system design scheme has been proposed including the main connection mode of converter stations, the operation mode, the control strategy, parameters design for main circuit and determination of converter station's power operation range. This technical solution can provide complete design method for future HVDC flexible transmission project, which is of great significance to the development and engineering application of the HVDC flexible technology in China. [ABSTRACT FROM AUTHOR]

[Display omitted] • A downscaling method to modify ESV by introducing LER was proposed. • Changes in LER and ESV in Nanjing City were consistent from 2000 to 2020. • Ecological restoration programs partially offset the impact of urbanization on ESV. • Water body dominated the ESV and had an important impact on change in ESV. • Proposed method will be valuable for sustainable ecosystem management. The scientific assessment of ecosystem service value (ESV) and landscape ecological risk (LER) is important for ecological security and sustainable development. However, existing studies often separate ESV and LER for a single evaluation, and the single evaluation is limited in guiding ecological conservation. Therefore, proposing an evaluation framework that integrates ESV and LER is urgent. Taking Nanjing City as an example, this study evaluated LER based on the risk evaluation cell and introduced it into ESV evaluation. Then, the influence of land use/land cover change on LER and ESV from 2000 to 2020 was analyzed. The results showed that built-up land and water body/wetland increased by 881.96 km2 and 41.41 km2, and farmland and forest land decreased by 875.46 km2 and 55.83 km2 from 2000 to 2020. The LER was low in the middle and high in the north and south. From 2000 to 2010, the LER increased from 0.67 to 0.68, and it then decreased to 0.61 in 2020. Medium-low risk regions decreased during 2000–2010, and low-risk regions increased and medium-high risk regions decreased during 2010–2020. The ESV increased by 0.77 billion United States dollars (USD) during 2000–2010 but decreased by 0.40 billion USD during 2010–2020. Under the impact of LER, the ESV per unit area of the farmland, forest land, and water body decreased during 2000–2020. The ESV of the water body dominated the total ESV and had an important influence on the change in total ESV. The ESV in Nanjing City during 2000–2020 mainly showed High-High autocorrelation and a few Low-High autocorrelations. Ecological restoration programs increased ESV during 2000–2010, but rapid urbanization reduced ESV during 2010–2020. Integrating social, economic, and ecological resources is necessary to realize the coordinated development of the economy and ecology. The results can provide an important reference for landscape planning and ecosystem management. [ABSTRACT FROM AUTHOR]

China has experienced an unparalleled urbanization process in recent decades, which has dramatically changed the water environment. Quantification of the water environment carrying capacity (WECC) is crucial given its importance to sustainable development. Existing studies have typically focused on the overall WECC system and lacked analysis of its internal features. In this study, the concepts, calculations, and classifications of the WECC were further developed. Using Nanjing, China, as a case study, we developed a hierarchical evaluation indicator system including three system layers (social, environmental and economic subsystems). We applied the entropy weight and fuzzy comprehensive evaluation method to evaluate the temporal variation tendency of WECC, and explored the deep-seated problems stemming from urbanization. The results indicated that WECC in Nanjing was 0.3045–0.5302 during 2006–2017, thus approaching a moderate grade with a relatively slow growth rate. Social, environmental, and economic subsystems increased by 29.3%, 83.1%, and 97.2%, respectively. Overall, Nanjing had a solid foundation regarding its economic subsystem, but its social and environmental subsystems were under pressure. Factors such as slow population growth as well as reduced energy and water use intensity improved WECC, whereas factors such as increased population density and excessive water consumption blocked WECC. Practical suggestions were proposed to resolve the primary problems of the WECC under urbanization. This holistic approach is urgently needed to achieve water environmental sustainability, both for Nanjing and for other emerging cities.

An understanding of historical and present land use and land cover (LULC) information and its changes, such as urbanization and urban growth, is critical for city planners, land managers and resource managers in any rapidly changing landscape. To deal with this situation, the development of a new supervised classification method for multitemporal LULC mapping with long-term reliable information is necessary. The ultimate goal of this study was to develop a new classification method using harmonic analysis with a minimum spectral distance algorithm for multitemporal LULC mapping. Here, the Jiangning District of Nanjing City, Jiangsu Province, China was chosen as the study area. The research methodology consisted of two main components: (1) Landsat data selection and time-series spectral reflectance reconstruction and (2) multitemporal LULC classification using HA with a minimum spectral distance algorithm. The results revealed that the overall accuracy and Kappa hat coefficients of the four LULC maps in 2000, 2006, 2011, and 2017 were 97.03%, 90.25%, 91.19%, 86.32% and 95.35%, 84.48%, 86.74%, 80.24%, respectively. Further, the average producer accuracy and user accuracy of the urban and built-up land, agricultural land, forest land, and water bodies from the four LULC maps were 92.30%, 90.98%, 94.80%, 85.65% and 90.28%, 93.17%, 84.40%, 99.50%, respectively. Consequently, it can be concluded that the newly developed supervised classification method using harmonic analysis with a minimum spectral distance algorithm can efficiently classify multitemporal LULC maps.

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In order to understand the regional water resources carrying status and socio-economic development potential, it is necessary to clarify the threshold of water resources supporting the socio-economic scale. By analyzing the basic connotation of water resources carrying capacity (WRCC) and optimizing allocation of water resources, the calculation method of WRCC was further elaborated. Nanjing was selected as the research area and 2015 was the typical year. The change of WRCC of Nanjing after the water resources allocation was calculated and compared with the result of the WRCC to analyze the carrying status of water resources in Nanjing. The results show that the water resources allocation effectively improves the WRCC and relieves the pressure on water resources. [ABSTRACT FROM AUTHOR]

In order to make full use of national monitoring sites data, the variations of mass concentrations of PM2.5 and other criteria pollutants in Nanjing City were investigated on the basis of data from nine national monitoring sites. These monitoring sites provide 24 hr average data to evaluate the spatiotemporal variations of PM2.5 mass concentration. The characteristics of the annual, seasonal, monthly and hourly variations of PM2.5 mass concentrations were analysed. PM2.5 concentrations were higher in the winter months, yet lower in the summer and whole afternoon time, but became better and better during 2014-2016. Afterwards Pearson correlation coefficients were calculated between PM2.5 and other criteria pollutants. The correlation coefficients between PM2.5 and PM10 at 9 monitoring sites were more than or equal to 0.76, and were lower in spring while higher in winter, summer and fall. However, the correlation between PM2.5 and SO2, NO2, CO varied in four seasons with lower correlation in summer and higher correlation in winter, spring and fall. Through calculating hourly correlation coefficients between PM2.5 and PM10, SO2, NO2, the correlation coefficients between PM2.5 and PM10 were lower in the afternoon, on the contrary, the correlations of PM2.5 and SO2, NO2 were lower in the night-time and morning. The correlation curves of PM2.5 and O3 barely changed, which gives us the information that O3 was weakly correlated with PM2.5. The investigation of PM2.5 and other criteria pollutants may provide some implications for the key reasons leading to the regional high PM2.5 and lay the foundation for further research of PM2.5 control strategies in Nanjing. [ABSTRACT FROM AUTHOR]

Green facade is an important strategy to improve the urban eco-environment and reduce the negative effects of human activities in central districts of cities which are land-scarce and lack green spaces. We first summarized the limiting factors for the construction of green facades locally and internationally. Then, we used the Xinjiekou District of Nanjing City in China as a case study area, and selected the wind environment, solar environment, and physical build environment that might impact the potential development of green facades as key factors to quantitatively analyze singlely by geographic information systems (GIS) and computational fluid dynamics (CFD). Finally, the potential area to develop green facades was assessed through a multi-factor overlay analysis. The results showed that 17726 m² of wall spaces in the Xinjiekou District had a high potential for facade greening, accounting for 30.8% of all exterior wall space under a height of 12 m and 17.3% of the entire study area. Sunlight was a key limiting factor in determining whether a green facade should be developed. Irrigation was identified as another important factor that might strongly affect the growth of vertical vegetation in urban environment. The spatial distribution of walls suitable for facade greening was uneven, with an "inner-high and south-high" spatial pattern. Our results would help to guide the design and development of green facades in Xinjiekou, and also provide a reference for planning and utilizing green wall space projects in other built and dense urban areas. [ABSTRACT FROM AUTHOR]

In this paper, the artificial neural network (ANN) model was used to evaluate the degree of intensive urban land use in Nanjing City, China. The construction and application of the ANN model took into account the comprehensive, spatial and complex nature of urban land use. Through a preliminary calculation of the degree of intensive land use of the sample area, representative sample area selection and using the back propagation neural network model to train, the intensive land use level of each evaluation unit is finally determined in the study area. Results show that the method can effectively correct the errors caused by the limitations of the model itself and the determination of the ideal value and weights when the multifactor comprehensive evaluation is used alone. The ANN model can make the evaluation results more objective and practical. The evaluation results show a tendency of decreasing land use intensity from the core urban area to the periphery and the industrial functional area has relatively low land use intensity compared with other functional areas. Based on the evaluation results, some suggestions are put forward, such as transforming the mode of urban spatial expansion, strengthening the integration and potential exploitation of the land in the urban built-up area, and strengthening the control of the construction intensity of protected areas. [ABSTRACT FROM AUTHOR]

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Simulation models based on cellular automata (CA) are widely used for understanding and simulating complex urban expansion process. Among these models, logistic CA (LCA) is commonly adopted. However, the performance of LCA models is often limited because the fixed coefficients obtained from binary logistic regression do not reflect the spatiotemporal heterogeneity of transition rules. Therefore, we propose a variable weights LCA (VW-LCA) model with dynamic transition rules. The regression coefficients in this VW-LCA model are based on VW by incorporating a genetic algorithm in a conventional LCA. The VW-LCA model and the conventional LCA model were both used to simulate urban expansion in Nanjing, China. The models were calibrated with data for the period 2000–2007 and validated for the period 2007–2013. The results showed that the VW-LCA model performed better than the LCA model in terms of both visual inspection and key indicators. For example, kappa, accuracy of urban land and figure of merit for the simulation results of 2013 increased by 3.26%, 2.96% and 4.44%, respectively. The VW-LCA model performs relatively better compared with other improved LCA models that are suggested in literature. [ABSTRACT FROM PUBLISHER]

Understanding the changes in water consumption structure in order to take measures for demand control is very important for sustainable water resources management. In this study, using the Southern China area of Nanjing as an example, we employed the information entropy method to analyze the water consumption structure, as well as the grey incidence analysis to analyze synthetic incidence degree of the factors associated with agricultural, industrial, domestic, and ecological water consumption. The results show that the degree of balance among water consumption sectors has increased from 0.755 to 0.825 between 1993 and 2014. Gradual decrease of the relative proportion of a single water user structure in a water consumption system has made the utilization of water resources in Nanjing rational and diversified. The study identifies three stages of transformation of water structure in Nanjing, namely, a growth period from 1993 to 2002, an adjustment period from 2003 to 2010, and another growth period from 2011 to 2014. The synthetic incidence degree analysis indicates that adjustments of the agricultural and industrial water consumption as well as water saving measures are the main factors that affected water consumption structure in Nanjing. It is expected that the results obtained from this study will provide references to optimize the utilization of urban water resources. [ABSTRACT FROM AUTHOR]

HJ-1A/B NDVI (HJ NDVI) time-series data possess relatively high spatio-temporal resolution which is significant for the research on urban areas. However, its application is hindered by noise resulting from the restrictions of imaging quality and limits of the satellite platform. The NDVI noise reduction is necessary. Some noise-reduction techniques including the asymmetric Gaussian filter (AG), the double logistic filter (DL), the Savitzky-Golay (S-G) filter and the harmonic analysis (Hants) of NDVI time-series have been used to carry out the NDVI time series reconstruction, and based on the comparison results of different filter, S-G filter is the optimal in the application on urban areas. Finally,urban vegetation mapping is carried out based on the new HJ NDVI. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Centralized peasant residence (CPR) is a typical phenomenon in rapid urbanization. The majority of farmers passively change their living and residential styles. The phenomenon has aroused wide concern because it reflects the peasants' life satisfaction and determines their well-being. In this paper, resident satisfaction is evaluated based on six typical CPRs in Nanjing using a fuzzy approach. Results indicate that residents in rural residential areas are satisfied with their social life and location. However, they have a relatively lower satisfaction with their economic situation and community facilities. Nearly 57.5% of respondents are concerned more about their employment and economic situations and less about community life and housing conditions. Considering the life satisfaction priority from four dimensions, improving the life satisfaction priority of rural-concentrated residential areas is suggested. We propose that the CPR location should be increasingly emphasized, and the best approach for ensuring satisfied people in CPRs is simultaneously improving their living condition, job accessibility, and public service. Furthermore, increased attention should be given to jobs, commute time, and cost of living. Rural communities should be surrounded by a new industrial park to realize employment and live integration. [ABSTRACT FROM AUTHOR]

The existing researches on the influence of information and communication technology (ICT) are mainly focused on human activity, whilst with few efforts on urban space. In the e-society, the widespread adoption of ICT devices not only affects almost every aspect of people's daily life and thereby reshapes the spatial development of regions and cities, but also generates a large amount of real-time activity data with location information. These georeferenced data, however, have relatively recently attracted attention from geographers. Adapted from Lynch's framework based on people's perceptions, this paper proposes a framework of urban spatial structure based on people's actual activity, including five elements, namely activity path, activity node, central activity zone (CAZ), activity district, and activity edge. In the empirical study, by using one week's check-in tweets (from February 25 to March 3 in 2013) collected in Nanjing City, the five elements are recognized and analyzed. Through the comparison between our results and urban spatial structure based on population (and land use), we argue that ICT uses: 1) lead to polarize, rather than to smooth, the urban structural hierarchy, due to the dual role of distance; 2) enable a partial decoupling of activity and activity space node, which challenges our conventional understanding of the role of home and the utility of travel; 3) blur the boundaries of activity districts and hence may play a positive role in enriching districts' functions, which should not be overlooked in the current urban transformation in China. [ABSTRACT FROM AUTHOR]

Based on the remote sensing image in 1996, 2002 and 2010, with the help of RS and GIS technology, and using the Probit regression model, this paper analyzed the characteristics of land use change in Nanjing City from 1996 to 2010, and the driving factors of land use change. The results showed that the cultivated land and woodland decreased, constructive land, garden plot and grassland continued to increase, and the comprehensive land use change rate was rising since 1996. The results of regression model for cultivated land and woodland change indicated that the change of cultivated land in the years 1996-2002 was mainly affected by the factors of "distance to the nearest rural settlement" and "farmers' population density". However, in the years 2002-2010 it was mainly affected by the factors of "change of per area GDP", "distance to the rural settlement" and "distance to the nearest road". The change of woodland in the years 1996-2002 was mainly affected by the factors of "the elevation" and "distance to the rural settlement". However, in the years 2002-2010 it was mainly affected by the factors of "change of per area GDP", "population density" and "distance to the nearest road". By comparison, the early driving factors of land use change were mainly natural factors, but in recent years, they were mainly social, economic and demographic factors. [ABSTRACT FROM AUTHOR]

Due to the global increases in urbanisation rates, urban sprawl has become a worldwide issue. In China, the development of rural areas has been affected by urban expansion and adjustments of metropolitan areas by administrative divisions that have led to losses in agricultural lands and ecosystem services. There is the 'paradoxical' desire for governments to promote rural development and protect land resources. Urban fringe sprawl is a prominent issue in the process of rural development. Identifying and measuring sprawl at the urban fringe could assist policymakers to either encourage or discourage this phenomenon. This paper demonstrates use of multidimensional indicators to effectively measure urban fringe sprawl by remote sensing, in addition to demographic and socio-economic data. Using integrated indicators observed in the recent Chinese development context, urban fringe sprawl was measured comprehensively for Jiangning, a district in the city of Nanjing, China. This study indicates that Jiangning is sprawling rapidly. The results also show that the multidimensional indicator approach could provide decision support to create effective long-term land-use planning policies for controlling urban sprawl patterns. [ABSTRACT FROM AUTHOR]

Through the matching relationship between land use types and carbon emission items, this paper estimated carbon emissions of different land use types in Nanjing City, China and analyzed the influencing factors of carbon emissions by Logarithmic Mean Divisia Index (LMDI) model. The main conclusions are as follows: 1) Total anthropogenic carbon emission of Nanjing increased from 1.22928 × 10 t in 2000 to 3.06939 × 10 t in 2009, in which the carbon emission of Inhabitation, mining & manufacturing land accounted for 93% of the total. 2) The average land use carbon emission intensity of Nanjing in 2009 was 46.63 t/ha, in which carbon emission intensity of Inhabitation, mining & manufacturing land was the highest (200.52 t/ha), which was much higher than that of other land use types. 3) The average carbon source intensity in Nanjing was 16 times of the average carbon sink intensity (2.83 t/ha) in 2009, indicating that Nanjing was confronted with serious carbon deficit and huge carbon cycle pressure. 4) Land use area per unit GDP was an inhibitory factor for the increase of carbon emissions, while the other factors were all contributing factors. 5) Carbon emission effect evaluation should be introduced into land use activities to formulate low-carbon land use strategies in regional development. [ABSTRACT FROM AUTHOR]