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Multi-scale data have had a wide-ranging level of performance in the area of urban change monitoring. Herein we investigate the correlation between the impervious surface fraction (ISF) and the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime stable light (NTL) data with respect to the urban expansion in the main districts of Guangzhou. Landsat 5 Thematic Mapper and Landsat 8 Operational Land Image (OLI) data from 1988 to 2015 were used to extract the ISF using the linear spectral mixture analysis model and normal difference build-up index at the sub-pixel scale. DMSP/OLS NTL data from 1992 to 2013 were calibrated to illustrate the urban nighttime light conditions at the regional scale. Urban expansion directions were identified by statistics and kernel density analysis for the ISF study area at the sub-pixel scale. In addition, the correlation between the ISF and DMSP/OLS NTL data were illustrated by linear regression analysis. Furthermore, Profile Graph in ArcGIS was employed to illustrate the urban expansion from the differences in correlation in different directions. The conclusions are as follows: 1) The impervious surface (IS) in the study area has expanded to the northeast and the east, starting with the old urban zones, and the high-density IS area has increased by 321.14 km2. 2) The linear regression analysis reveals a positive correlation between the ISF and the DMSP/OLS NTL data. The multi-scale data changes are consistent with the actual urban planning of Guangzhou. 3) The DMSP/OLS NTL data overestimate the urban extent because of its saturation and blooming effects, causing its correlation with ISF to decrease. The pattern of urban expansion influences the saturation and blooming effects of the DMSP/OLS NTL data.

In the process of compact city development, the limited availability of the land resources for green space (GS) would represent a major challenge for urban environments. In this paper, the long-term compact urbanization process of an island city (Xiamen, China) was selected as an example to analyze the historical spatial patterns of GS within the built environment. This study focused on urban GS at a neighborhood scale to analyze GS on a fine scale. Urban GS was extracted using the normalized difference vegetation index based on GF-1 remote sensing images. The results revealed several trends: (1) Newer built-up areas had a larger proportion of GS, more diversified GS types, and larger per-capita GS area. (2) The proportion of GS within various urban functional land use types presented great differences, both at the class level (age of the built-up area) and at the landscape level (the entire built-up area). (3) Significant differences in the proportion of GS and per-capita GS area were identified among various residential land types. The results from this study can contribute to the practical application of urban planning and policy-making.

The urban heat island effect caused by the rapid increase in urban anthropogenic heat has gradually become an important factor affecting the living environment of urban residents. Studying the temporal and spatial variation characteristics of urban anthropogenic heat is of great significance for urban planning and urban ecological service systems. In this study, the urban anthropogenic heat flux (AHF) in 2004, 2009, 2014, and 2020 in the central urban area of Guangzhou was retrieved based on Landsat data and the surface energy balance equation, and the temporal and spatial characteristics of different types of anthropogenic heat were explored by combining the transfer matrix and the migration of the gravity center. The results showed that: (1) The overall change trend of anthropogenic heat in the central urban area of Guangzhou was enhanced, and the degree of enhancement was related to the type of urban functional land. (2) Different types of anthropogenic heat had different characteristics in terms of area expansion and spatial changes. Low-value anthropogenic heat (zero-AHF zone, low-AHF zone, medium-AHF zone) changed drastically in terms of area expansion. High-value anthropogenic heat (medium-AHF zone, high-AHF zone) changed more drastically in space. The increase in urban population, rapid economic development, and increased industrial production activities have stimulated the emission of anthropogenic heat, which has a positive impact on the intensity of anthropogenic heat.

This study explored the model of urban impervious surface (IS) density, land surface temperature (LST), and comprehensive ecological evaluation index (CEEI) from urban centers to suburbs. The interrelationships between these parameters in Guangzhou from 1987 to 2019 were analyzed using time-series Landsat-5 TM (Thematic Mapper), Landsat-8 OLI (Operational Land Imager), and TIRS (Thermal Infrared Sensor) images. The urban IS densities were calculated in concentric rings using time-series IS fractions, which were used to construct an inverse S-shaped urban IS density function to depict changes in urban form and the spatio-temporal dynamics of urban expansion from the urban center to the suburbs. The results indicated that Guangzhou experienced expansive urban growth, with the patterns of urban spatial structure changing from a single-center to a multi-center structure over the past 32 years. Next, the normalized LST and CEEI in each concentric ring were calculated, and their variation trends from the urban center to the suburbs were modeled using linear and nonlinear functions, respectively. The results showed that the normalized LST had a gradual decreasing trend from the urban center to the suburbs, while the CEEI showed a significant increasing trend. During the 32-year rapid urban development, the normalized LST difference between the urban center and suburbs increased gradually with time, and the CEEI significantly decreased. This indicated that rapid urbanization significantly expanded the impervious surface areas in Guangzhou, leading to an increase in the LST difference between urban centers and suburbs and a deterioration in ecological quality. Finally, the potential interrelationships among urban IS density, normalized LST, and CEEI were also explored using different models. This study revealed that rapid urbanization has produced geographical convergence between several ISs, which may increase the risk of the urban heat island effect and degradation of ecological quality.

The interaction between urbanization and the eco-environment is usually viewed as an effect–feedback framework. Its coupling system is composed of urbanization and eco-environment subsystems. In this paper, the coupling degree (CD) and the coupling coordinated degree (CCD) are used to reflect the coupling interaction and coupling coordination between the urbanization subsystem and the eco-environment subsystem. Based on the dynamic relative quantities of urbanization and eco-environment data in the Pearl River Delta, CD and CCD values were calculated, and the spatiotemporal evolution trend of coordination was analyzed. The results show that (1) from 2000 to 2015, the nine cities in the Pearl River Delta had high CD values and CCD values. Though they had different performances in different periods, they were all in a coordinated class, including good coordination (GC), moderate coordination (MC), and bare coordination (BC). (2) In terms of temporal evolution, the coupling coordination between urbanization and the eco-environment in the entire Pearl River Delta greatly improved. (3) From the perspective of spatial distribution, the coupling coordination of the central region was higher than that of the peripheral regions, and that of the west bank of the Pearl River was higher than that of the east bank of the Pearl River. These results can help local policy makers enact appropriate measures for sustainable development.

Urban agglomeration (the spread of cities into large agglomerations) has become the main form of urbanization in China, and natural ecosystems surrounding the urban areas are becoming degraded and fragmented as a result. Although ecological indicators have been widely used to assess the regional ecological stress resulting from urbanization, few of them consider spatial adjacency relationships between urban and natural landscapes. From this perspective a novel ecological indicator, the Eco-Erosion Index (EEI), was developed and applied to assess the regional ecological stress caused by urban agglomeration development across 26 cities in the Yangtze River Delta, China (YRD). We analyzed: i) temporal change in land use and land cover (LULC) and ecosystem services value (ESV) in YRD from 1990 to 2010, ii) spatiotemporal dynamics of EEI of YRD at different scales: provincial, municipal, and 5 km-grid, iii) inter-relationships between EEI and LULC and ESV to explore its effectiveness as an indicator. The results showed that urban agglomeration in YRD has led to increasing regional ecological stress from 1990 to 2010. EEI values increased from 0.197 in 1990 to 0.321 in 2010. The closer to Shanghai City, the greater the EEI values of the cities become. EEI is highly related with LULC and ESV but integrates these two variables as it represents both the spatial occupation and landscape adjacency effects. The EEI values demonstrate some scale effects, and EEI at fine scale provides useful information to guide sustainable urban landscape management.

This study evaluated the spatio-temporal change characteristics of urban development at different scales with time-series impervious surface fractions. Landsat-5 Thematic Mapper (TM) and Landsat-8 Operational Land Imager (OLI) images were used to extract impervious surface fractions using a modified linear spectral mixture analysis method in Guangzhou from 1988 to 2015. The results indicated that the impervious surface area has substantially increased, from 70.3 km2 in 1988 to 580.5 km2 in 2015. In 2015, the impervious surfaces were distributed almost throughout the whole region of the study area, except in the forest region. Next, impervious surface weighted mean centre (ISWMC) and the standard deviational ellipse (SDE) methods were used to systematically analyse the principle orientation, direction, spatio-temporal expansion trends, and the distribution differences of impervious surfaces at the whole and local region scales from 1988 to 2015. The spatio-temporal dynamics of ISWMC exhibited different expansion directions and intensities of impervious surfaces at the whole and local region scales. On a whole region scale, the principle expansion direction of impervious surfaces was northward. However, the expansion trend of impervious surfaces in the different districts was significantly different from other trends at the local region scale. The parameters of SDE were used to investigate the orientation and the clustering or dispersion degree of impervious surface at different scales. The results from SDE analysis indicated that the impervious surfaces exhibited uncertainty in the expansion direction at the whole region scale; in contrast, they had a distinct preferred orientation and expansion direction at the local region scale. The analysis revealed that urban expansion exhibited different change characteristics in various directions at the local region scale. In summary, the results at the local region scale can better reflect the change trajectory of spatio-temporal dynamics of urban development and its fine spatial structure than at the whole region scale.

Soil plays an important role in carbon storage. Accordingly, urban soil carbon and its storage have great impacts on urban carbon balance and future urban sustainable development. In this study, 151 traffic road soils in five urban functional areas were selected. The discrepancies of field soil respiration, soil physiochemical conditions among urban functional areas were calculated. Factor analysis and the Geographic Detector (GeoD) factor model showed that heavy metals had the most important impacts on soil respiration, followed by organic matter and urban function. Using the geographic detector method, individual factors and their interaction effects on soil respiration were tested. The GeoD interaction model demonstrated that no-linear enhanced interaction exhibited between C and ecological function, between N and residential function, S and industrial function. Moreover, no-linear enhanced interaction existed between Ti and ecological function, between Hg, Zn, Ni and residential function. The GeoD risk detector indicated that Soil temperature, N and Hg in different categories had obvious traffic road soil respiration impacts discrepancy. Overall, the results of this study will be useful for further investigation of urban soil treatment to enable healthy urban functional development.

Background Achieving urban sustainability is the ultimate destination of urban development. City rankings as one of the sustainability assessment tools have received increasing attention from the scientific community. However, few study assesses Chinese cities’ sustainability performance using the big data of existing city rankings. Aim This study aims to assess Chinese cities’ sustainability performances based on the outcomes of the existing internet big data of city rankings. Methods The outcomes of city rankings were used as the raw dataset. The “sustainability” of city rankings, city’s appearance frequency, and its ranking place were comprehensively considered during evaluation processes. By considering the above factors, the scores of different cities were calculated in terms of overall sustainability and domain sustainability. Furthermore, the GeoDetector was applied to explore the association between social-economic and overall ranking scores as well as the interrelation among TBL dimensions. Results Chinese cities’ sustainability performance was extremely uneven in spatial distribution. In terms of overall and domain sustainability, well-performing cities were aggregated in the Beijing-Tianjin-Hebei, the Yangtze River Delta, and the Pearl River Delta metropolitan regions. The top ten sustainable cities were Hangzhou, Beijing, Shenzhen, Guangzhou, Zhuhai, Hong Kong, Tianjin, Suzhou, and Xiamen. Most cities did not reach good coordination among the TBL dimensions, instead of developing well in one or two aspects. The results also revealed that current city rankings eyeing more economic and social development, while considering less environmental dimension. Moreover, TBL dimensions mutually reinforce each other in sustainable city construction. The environmental pillar played a critical role and interacting with other dimensions significantly enhanced urban sustainability. Conclusion The outcomes of existing city rankings can be used as a new resource to evaluate cities’ sustainability performance. Current city rankings in China are not systematically considered in terms of TBL dimensions. Cities should enhance the coordination among TBL pillars, and increase the attention on environmental dimension. More empirical studies involving big data of city rankings will contribute to a new perspective to promote the practice of sustainable urbanization in China.

Since there is an increasing demand for integrating landscape ecology and urban planning theories to study complex urban ecosystems and establish rational and ecological urban planning, we introduced a new concept-urban functional landscapes which can be reclassified based on detailed land use data to fulfill the various urban functions, such as residential, commercial, industrial, and infrastructure purposes. In this paper, urban functional landscapes were defined based on urban land use data produced from Pleiades images, and then landscape metrics and population density were combined to identify the urban functional zones along an urban–rural gradient. The features of urban functional landscape patterns and population density were also analyzed, and their relationship has been explored. The results showed that the pattern of urban functional landscapes and population density in the urban functional zones (Urban center, Urban peripheral area, Landscape barrier, Satellite city and Far-suburb) along the urban–rural gradient in Xiamen doesn't totally conform to the classical theories in spatial and social aspects. Urban functional landscapes is potential of acting as bridges between the landscape ecology and urban planning theories, providing scientific support for rational urban landscape planning and urban land use policy making.

Green roofs are thought to be an effective measure to solve the contradiction between land shortages and ecological construction, especially address urban heat island (UHI) effects in high-density urban areas. However, few empirical studies have focused on the cooling effect of green roof projects at urban scales. This study quantified the cooling effect of green roofs in Xiamen Island, China, where 540,000 m2 of green roofs were implemented between 2015 and 2017, in order to address the two research questions: (1) do green roofs in high-density urban areas have a significant cooling effect at the city scale and (2) what is the extent of the cooling? The relative difference between the average land surface temperature (LST) of Xiamen Island and the green roofs stemmed from Landsat 8 remote sensing image in the summers of 2014 and 2017 were calculated in geographic information systems (GIS) to represent the cooling effect of green roof project. Results showed that: (1) the average LST difference between green roofs and Xiamen Island decreased by 0.91 °C, indicating that green roofs could effectively alleviate UHI effects in high-density urban areas; (2) The cooling effect was significant up to 100 m from the green roof installation in Xiamen Island, we called it as characteristic cooling buffer zone; (3) Regression analysis revealed that for every 1000 m2 increase in green roof area, the average LST of the roof and its characteristic cooling buffer zone decreased by 0.4 °C. These findings provide the empirical proof for the cooling effect of green roofs on the surrounding environment in high-density urban areas and important insights for urban planners and government agencies for the effective mitigation of UHI impacts.

Residential spatial differentiation, also called residential segregation, is a representation of the differentiation of social stratum in economic income, social status, education degree, lifestyle, and other aspects, based on an urban geographical space. In this paper, Xiamen Island is taken as example to calculate the dissimilarity index and the multi-group dissimilarity index at three scales (districts, sub-districts, and communities) by using the land area, population size, and green space area of different housing types. The characteristics of residential differentiation are analyzed. It is found that both spatial differentiation and multi-group spatial differentiation have significant scale effects. The smaller the scale of the spatial statistics unit, the larger the spatial differentiation and multi-group spatial differentiation. Significant differences are found in residential differentiation among different housing types. The residential differentiation is, not only demonstrated in land area and population size, but also in the resources of green space. More importantly, a balanced allocation of green space will help to reduce the degree of residential differentiation. With urban expansion and social-economic development, residential spatial differentiation will likely change. An understanding of residential differentiation is a guide for urban master planning and detailed regulatory planning. It will help to promote social harmonious development and urban sustainable development by the reasonable configuration of land and resources.

The Pearl River delta is one of the most densely populated areas in China, with high urbanization and rapid economic development. The drama change of land use in recent years has been matched by rising pollution of water. With monitoring data of water quality and Landsat OLI8 images 2013, this paper analyzed the relationship between land use and water quality in the river net area of Pearl River delta. Using redundancy analysis method, correlations were conducted at four spatial scales from 100 m to 1000 m in the riparian buffers. The results showed that the land use structure had a great impact on water quality parameters. The urban land had negative effect and the increase of urban impervious surface exacerbated the deterioration of water quality. The arable land showed positive effect on water quality. This was partly because the arable land had a certain absorption and retention, preventing pollutants to the river. On the other hand, the negative impact of arable land was covered up by urban land for the relatively low area proportion. The forest and water had a positive effect on water quality. The forest was more relevant to water quality in small riparian zone scale. With the increase of riparian zone scale, the correlations of the arable land and urban land to COD Mn were first increased and then decreased. The correlation between the water in the riparian buffers and the water quality in the net river was strong, which increased constantly with the scale of riparian zone. The research could provide critical information in landscape planning and environmental protection.

In this paper, 6 types of coastal wetland (River, Dike-pond, Lake, Tidal flat, Swamp, Shallow sea waters) was classified precisely through supervised method and decision trees based on DEM, depth contour, high tide level, low tide level, vegetation coverage and soil map. Landscape metrics including area metrics, shape metric, aggregation metric and diversity metric were used to analysis the coastal wetland changes on class-level and landscape-level in 1995, 2001, 2005, 2009 and 2015. The results showed that the landscape pattern changed greatly in recent 20 years, especially since 2009, the coastal wetland area decreased sharply, distribution of coastal wetlands is becoming more and more uneven and the fragmentation is becoming more and more serious. Our study will provide scientific supports for coastal wetland planning and development policy making.

According to the actual situation of Pearl River basin and the existing evaluation index systems of river-lake health, a new evaluation index system of river-lake health in Pearl River basin was built. The river-lake health assessment system was built using ArcGIS as a development platform. The data was obtained based on remote sensing and GIS. The rapidness and visualization of river-lake health assessment were realized by this system, which could support the protection services in Pearl River basin.

The eco-security of Dongjiang watershed was evaluated in 1988, 1998 and 2007 separately after the eco-security index system establishment, which included three first-class indicators and eighteen second-class indicators based on P-S-R model. The eco-security dynamic degree was built to analysis the temporal and spatial variation of the countries and cities. Some guiding ideas and practicing tactics has been put forward to promote the watershed eco-security.

Applies the geospatial information technology in the internet of things field is the internet of things development inevitable trend, regardless of is in the internet of things operation stratification aspect, the management stratification aspect in the policy-making stratification aspect, all needs the geospatial information technology to take the support. This article in view of the internet of things in the logistic distribution safe allocation and the management characteristic, the analysis in the internet of things in the logistic distribution management cannot satisfy safe requests at present and so on allocation, rapid reaction, conformity transportation and tracing, elaborated the geospatial information technology (GIS, GPS, GPRS) with the RFID technology in the South China characteristic agricultural product internet of things engineering research question and with the application, introduced in the internet of things the agricultural product safe allocation platform system design and contents and so on circulation tracing architecture, and its effective integration; Proposed initially the agricultural product tracing system pattern, and has carried on the overall structural design and the system function design take the agricultural product safe allocation and the tracing as the demand.

Assessment of the change of farmland use is of great important. After comparing the different ways of the assessment of farmland use change, a spatial assessment of the change of mountain range farmland use based on RS and GIS technology was presented. Such spatial assessment way has the virtue of quantified and visual characters. It use the land change information fast gained ability of RS, the formidable spatial data processing and the analysis ability which GIS provides, and integrating the statistical analysis software package. After the analysis to the primary factors reflects the farmland use, a spatiotemporal change model of had been put forward to assess the farmland use change. A comprehensive factor for sustainable development model (CISD) is made to reflect the region development situation. Finally, based on the mountain range farmland use change spatial assessment method mentioned above, the change of mountain range farmland use of Shaoguan city in Guangdong province (China)was studied, and a good effect was obtained. Such application proves the validity and feasibility of the spatial assessment method of the change of mountain range farmland use mentioned in this paper.

On the basis of quantitative remote sensing theories, we measured the water samples of Pear River in the same zone during the flood season and the dry season synchronously by spectrum instrument and traditional way, and made sure the correlation of the data simultaneously, then worked out the remote sensing reflectance for TM imagery relevant to the spectrum instrument. The suspended sediment concentration was determined by hydrologic observation site. Eight kinds of experiment models are derived from the correlation of the reflectance and the concentration .It is concluded that the spectrum of TM3 measured during flood season correlates best with suspended sediment concentration; And the ratio of TM3 to TM2 has the best correlation with the concentration beyond the flood season. Based on the results, the results of models correspondingly with each season are better.