220 results on '"Wenhui Kuang"'
Search Results
2. Virtual reality modeling application based on multi perspective and deep learning in the new media presentation and brand building of Dongguan City memory.
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Yunfeng Ye, Huifang Liu, Wenhui Kuang, and Wenxuan Chen
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- 2024
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3. Impact of urbanization on terrestrial carbon storage loss in the Hohhot-Baotou-Ordos region, China: evaluating people-space interactions
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Sargai, Yulin Dong, Wenhui Kuang, Yuhai Bao, Yinyin Dou, and Junzhi Wang
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Urbanization ,terrestrial carbon storage ,per capita urban area ,LCRPGR ,Sustainable Development Goals ,Inner Mongolia ,Mathematical geography. Cartography ,GA1-1776 - Abstract
ABSTRACTUrbanization improves the living environment of billions of people but negatively impacts the local carbon cycle as it encroaches on ecosystems. We analyzed this dual effect of urbanization by quantifying linkages between several indicators — urbanization-induced terrestrial carbon storage loss (uTCSL), per capita urban area (PCUA), and urban land use efficiency (LCRPGR) — within the Hohhot-Baotou-Ordos (HBO) region in 1990–2100. Results show that the growth of 4.45 million urban residents and 420.70 km2 urban area led to a uTCSL of 815.74 GgC in the HBO region in 1990–2020. The uTCSL contributed to improving the urban crowding indicated by PCUA but was subject to LCRPGR. The PCUA decreased by −33.75 m2/person under high land use efficiency (LCRPGR
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- 2024
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4. Mapping impervious surface distribution in China using multi-source remotely sensed data
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Guiying Li, Longwei Li, Dengsheng Lu, Wei Guo, and Wenhui Kuang
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impervious surface area ,integration of multi-source data ,viirs dnb ,modis ndvi ,landsat ,china ,Mathematical geography. Cartography ,GA1-1776 ,Environmental sciences ,GE1-350 - Abstract
Impervious surface area (ISA) data are required for such studies as urban environmental modeling, hydrological modeling, and socioeconomic analysis, but updating these datasets in a large area remains a challenge due to the complex urban landscapes consisting of different materials and colors with various spatial patterns. This research explores the integration of multi-source remotely sensed data for mapping China’s ISA distribution at 30-m spatial resolution. The integration of Visible Infrared Imaging Radiometer Suite Day/Night Band (VIIRS DNB) and Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI) data were used to extract initial ISA with spatial resolution of 250 m using a thresholding approach. The Landsat-derived NDVI and Modified Normalized Difference Water Index (MNDWI) were used to remove vegetation and water areas from the mixed pixels that existed in the initial ISA data. The spectral signatures of these ISA data were further extracted from Landsat multispectral images and used to refine the ISA data using expert knowledge. The results indicate that the integration of multi-source data can successfully map ISA distribution with 30-m spatial resolution in China with producer’s and user’s accuracies of 83.1 and 91.9%, respectively. These ISA data are valuable for better management of urban landscapes and for use as an input in other studies such as socioeconomic and environmental modeling.
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- 2020
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5. Examining Spatio-Temporal Dynamics of Ecological Quality in the Pan-Third Pole Region in the Past 20 Years
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Geer Hong, Wenfeng Chi, Tao Pan, Yinyin Dou, Wenhui Kuang, Changqing Guo, Runmei Hao, and Yuhai Bao
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ecological quality ,human activities ,spatio-temporal pattern ,comprehensive evaluation ,the Pan-Third Pole region ,Science - Abstract
Examining the ecology quality of the Pan-Third Pole region has implications for global environmental change and sustainable development. However, spatio-temporal evolution of ecological quality in this region is still lacking. In this study, 65 countries of the Pan-Third Pole region were selected. A comprehensive evaluation index system of ecological quality was constructed using a dataset containing remote sensing, ecological environment and socio-economic data to spatially quantify the ecological quality, as well as its change from 2000 to 2020. The results displayed that the average ecological quality of the Pan-Third Pole region was at a moderate level of 0.53. Spatially, the excellent ecological quality regions were mainly concentrated in East Asian countries, while the severe quality regions were located in the Middle East. From 2000–2020, areas with improved ecological changes accounted for 38.48% of the total area, and 10.66% of the total area experienced a decline; specifically, European countries had a large proportion of improved ecological quality areas, while East Asian countries had a significantly larger proportion of declining ecological quality areas. We also found that ecosystem changes and human activities had an influence on ecological quality in the Pan-Third Pole region. This study provides an important empirical study on ecosystem services in the region.
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- 2022
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6. New Evidences on Anomalous Phenomenon of Buildings in Regulating Urban Climate From Observations in Beijing, China
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Wenhui Kuang
- Subjects
urban building ,diurnal air temperature range ,radiation and heat fluxes ,climate regulation ,anthropogenic heat ,Astronomy ,QB1-991 ,Geology ,QE1-996.5 - Abstract
Abstract Urban buildings and parks play an important role in regulating urban climate and ecosystem services. Diurnal air temperature range (DTRa) of rocklike buildings is commonsensically regarded as higher due to no latent heat from evapotranspiration and its smaller thermal inertia compared to wet soil. Therefore, the building DTRa is supposed to be higher than that of parks due to its building fabric. However, we found an opposite phenomenon (smaller building DTRa than that of parks), and the underlying mechanisms explaining this phenomenon are unclear. Here we conducted, in Beijing (China), a long‐term observational campaign of standard meteorological variables and radiation/energy fluxes to provide a new valuable evidence (a part of external energy) to explain this phenomenon. The observations indicated external heat energies from horizontal advection and anthropogenic heat sources. We found a significantly lower building DTRa than that of parks (ΔDTRa =2.53±1.93 °C), with a maximum difference of 3.54±1.96 °C in autumn; which was mainly attributed to higher daily minimum air temperature. We also found the large differences in air temperature contribution between the buildings and the parks happened mainly at night. The external heat sources of the building contributed 16.71% to the nighttime air temperature, which was higher than that of the parks (8.39%). The more indoor and outdoor anthropogenic heat sources in the building footprints were the major cause of the slower decrease in Tmin. The comparison between buildings and parks can be extensively applied to analyzing the effects of urbanization on climate.
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- 2019
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7. Examining the impacts of urbanization on surface radiation using Landsat imagery
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Wenhui Kuang, Ailin Liu, Yinyin Dou, Guiying Li, and Dengsheng Lu
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radiation budget ,shortwave radiation ,longwave radiation ,net radiation ,atmospheric transmittance ,landsat ,Mathematical geography. Cartography ,GA1-1776 ,Environmental sciences ,GE1-350 - Abstract
Metropolitan Beijing is facing many environmental problems such as haze and urban heat island due to the rapid urbanization. Surface shortwave, longwave, and net radiations are key components of the surface-atmosphere radiation budget. Since megacities are affected by the thermal radiation of complex landscape structures and atmospheric environments, quantitative and spatially explicit retrieval from remotely sensed data remains a challenge. We collected the surface radiation fluxes from seven fixed sites representing different land-use types to calibrate the local parameters for remotely sensed retrieval of net radiation. We proposed a remote sensing–based surface radiation retrieval method by embedding the underlying land covers and integrating the observational data. The improved method is feasible to accurately retrieve surface radiation and delineate spatial characteristics in metropolitan areas. The accuracy evaluation indicated that the difference between remotely sensed and in situ observed net radiation ranged within 0~± 40 W· m−2. The root mean squared error of the estimated net surface radiation was 32.71 W· m−2. The strongly spatial heterogeneity of surface radiation components in metropolitan Beijing was closely related to land-cover patterns from urban area to outskirts. We also found that the surface net radiation had a decreasing trend from 1984 to 2014, and the net radiation in the urban area was lower than that in the outskirts. According to the surface radiation budgets, urbanization resulted in the cooling effect in net radiation flux in the daytime, which was stemmed from low atmospheric transmittances from massive aerosol concentration and high surface albedo from light building materials.
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- 2019
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8. Characteristics of Changes in Urban Land Use and Efficiency Evaluation in the Qinghai–Tibet Plateau from 1990 to 2020
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Shujing Fu, Xuexia Zhang, Wenhui Kuang, and Changqing Guo
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Qinghai–Tibet Plateau ,urbanization ,land use ,spatiotemporal evolution ,efficiency ,Agriculture - Abstract
The Qinghai–Tibet Plateau has seen decades of changes in land use/cover as a result of urbanization and regional planning policy. Research on the efficiency of social development aids in the pursuit of social and environmental sustainability. Based on CLUD and socioeconomic statistical data, this study systematically analyses the spatiotemporal evolution characteristics of urban land use in the Qinghai–Tibet Plateau and evaluates its social development efficiency from three perspectives—the holistic, the municipal, and urban hierarchy—by using indicators such as the Moran index, land use efficiency, and urban expansion speed and proportion. Results show that the urbanization rate climbed from 21.26% to 54.95%, and the area of urban lands increased from 201.93 km2 to 796.59 km2 from 1990 to 2020, with urban lands expanding from the Lanzhou–Xining City Area to the central and south of the Qinghai–Tibet Plateau. The holistic urban land use efficiency grew from 1.14 to 1.53, while the UPD decreased slightly from 1.44 to 1.31, and the UED increased steadily from 1.40 to 12.97 per decade. Moreover, we should pay attention to the rational allocation of land in human, social and ecosystem terms to comprehensively improve the quality of urbanization across the plateau.
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- 2022
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9. Hierarchical Urban Land Mappings and Their Distribution with Physical Medium Environments Using Time Series of Land Resource Images in Beijing, China (1981-2021).
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Tao Pan, Wenhui Kuang, Ruoyi Pan, Zhenguo Niu, and Yinyin Dou
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- 2022
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10. The Massive Expansion and Spatial Transformation of Potentially Contaminated Land Across China in 1990–2020 Observed from Remote Sensing and Big-data
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Yinyin Dou, Changqing Guo, Wenhui Kuang, Wenfeng Chi, and Mei Lei
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Geography, Planning and Development ,General Earth and Planetary Sciences - Published
- 2022
11. Mapping Global Urban Impervious Surface and Green Space Fractions Using Google Earth Engine
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Wenhui Kuang, Yali Hou, Yinyin Dou, Dengsheng Lu, and Shiqi Yang
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land cover mapping ,urban boundary ,spatiotemporal dynamics ,hierarchical classification ,urban environments ,Landsat ,Science - Abstract
Urban impervious surfaces area (ISA) and green space (GS), two primary components of urban environment, are pivotal in detecting urban environmental quality and addressing global environmental change issues. However, the current global mapping of ISA and GS is not effective enough to accurately delineate in urban areas due to the mosaicked and complex structure. To address the issue, the hierarchical architecture principle and subpixel metric method were applied to map 30 m global urban ISA and GS fractions for the years 2015 and circa 2020. We use random forest algorithms for retrieval of the Normalized Settlement Density Index and Normalized Green Space Index from Landsat images using Google Earth Engine. The correlation coefficients of global urban ISA and GS fractions were all higher than 0.9 for 2015 and circa 2020. Our results show global urban ISA and GS areas in circa 2020 were 31.19 × 104 km2 and 17.16 × 104 km2, respectively. The novel ISA and GS fractions product can show potential applications in assessing the effects of urbanization on climate, ecology, and urban sustainability.
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- 2021
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12. Evaluating the Dynamic Changes of Urban Land and Its Fractional Covers in Africa from 2000–2020 Using Time Series of Remotely Sensed Images on the Big Data Platform
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Zherui Yin, Wenhui Kuang, Yuhai Bao, Yinyin Dou, Wenfeng Chi, Friday Uchenna Ochege, and Tao Pan
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urban land mapping ,remotely sensed images ,impervious surface area fraction ,vegetation space fraction ,the whole Africa ,Science - Abstract
Dramatic urban land expansion and its internal sub-fraction change during 2000–2020 have taken place in Africa; however, the investigation of their spatial heterogeneity and dynamic change monitoring at the continental scale are rarely reported. Taking the whole of Africa as a study area, the synergic approach of normalized settlement density index and random forest was applied to assess urban land and its sub-land fractions (i.e., impervious surface area and vegetation space) in Africa, through time series of remotely sensed images on a cloud computing platform. The generated 30-m resolution urban land/sub-land products displayed good accuracy, with comprehensive accuracy of over 90%. During 2000–2020, the evaluated urban land throughout Africa increased from 1.93 × 104 km2 to 4.18 × 104 km2, with a total expansion rate of 116.49%, and the expanded urban area of the top six countries accounted for more than half of the total increments, meaning that the urban expansion was concentrated in several major countries. A turning green Africa was observed, with a continuously increasing ratio of vegetation space to built-up area and a faster increment of vegetation space than impervious surface area (i.e., 134.43% vs., 108.88%) within urban regions. A better living environment was also found in different urbanized regions, as the newly expanded urban area was characterized by lower impervious surface area fraction and higher vegetation fraction compared with the original urban area. Similarly, the humid/semi-humid regions also displayed a better living environment than arid/semi-arid regions. The relationship between socioeconomic development factors (i.e., gross domestic product and urban population) and impervious surface area was investigated and both passed the significance test (p < 0.05), with a higher fit value in the former than the latter. Overall, urban land and its fractional land cover change in Africa during 2000–2020 promoted the well-being of human settlements, indicating the positive effect on environments.
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- 2021
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13. Monitoring periodically national land use changes and analyzing their spatiotemporal patterns in China during 2015–2020
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Wenhui Kuang, Shuwen Zhang, Guoming Du, Changzhen Yan, Shixin Wu, Rendong Li, Dengsheng Lu, Tao Pan, Jing Ning, Changqing Guo, Jinwei Dong, Yuhai Bao, Wenfeng Chi, Yinyin Dou, Yali Hou, Zherui Yin, Liping Chang, Jiuchun Yang, Jiali Xie, Juan Qiu, Hansong Zhang, Yubo Zhang, Shiqi Yang, Rigai Sa, and Jiyuan Liu
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Earth and Planetary Sciences (miscellaneous) - Published
- 2022
14. Impact of Cropland Evolution on Soil Wind Erosion in Inner Mongolia of China
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Wenfeng Chi, Yuanyuan Zhao, Wenhui Kuang, Tao Pan, Tu Ba, Jinshen Zhao, Liang Jin, and Sisi Wang
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land-use/cover changes ,soil wind erosion ,cropland evolution ,sustainable path ,ecological barrier area of North China ,Agriculture - Abstract
Understanding soil erosion responses to cropland expansion/shrinking plays a crucial role in regional agriculture sustainability development in drylands. We selected Inner Mongolia, a typical water resource constraints region with acute cropland expansion, as the study area in China. Spatial cropland evolution and its impact on wind-driven soil erosion were investigated with the help of field sampling data, remotely sensed retrieved data, and the revised wind erosion model (RWEQ). Results showed that the cropland area of Inner Mongolia presented an increased growth trend, with a net increase area of 15,542.9 km2 from 1990 to 2018. Cropland characteristics in Inner Mongolia presented continuous growth in its eastern region, basically constant growth in its central region, and declined in its western region. Most cropland declines occurred after 2000 when the Grain for Green project began, which means that acute cropland expansion happened from 1990 to 2000. The soil wind erosion modulus showed a net increase with cropland expansion. The reclamation of forests and grasslands contributed to an increase of 5.0 million tons of the soil wind erosion modulus, 80% of which was produced in the eastern part of the region. The conversion from croplands to grasslands/forests caused a decrease of approximately 2.7 million tons, 62% of which was in the east and 25% in the west of the region. Considering the constraints of water shortage and over-exploitation of groundwater, we provide a path based on a balance between ”resource-production-ecosystem” to achieve ecologically sustainable agriculture development in the drylands of China.
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- 2021
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15. Investigating the Patterns and Dynamics of Urban Green Space in China's 70 Major Cities Using Satellite Remote Sensing.
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Wenhui Kuang and Yinyin Dou
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- 2020
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16. Interactions between the summer urban heat islands and heat waves in Beijing during 2000–2018
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Fengqi Cui, Rafiq Hamdi, Wenhui Kuang, Tao Yang, Huili He, Piet Termonia, and Philippe De Maeyer
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Atmospheric Science - Published
- 2023
17. The influence of urban three-dimensional structure and building greenhouse effect on local radiation flux
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Renhua Zhang, Shiqi Yang, Wenhui Kuang, and Zhao-Liang Li
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Absorption (acoustics) ,Radiation flux ,Radiant flux ,General Earth and Planetary Sciences ,Environmental science ,Radiant energy ,Flux ,Urban heat island ,Sensible heat ,Greenhouse effect ,Atmospheric sciences - Abstract
Accurate measurements of the three-dimensional structure characteristics of urban buildings and their greenhouse effect are important for evaluating the impact of urbanization on the radiation energy budget and research on the urban heat island (UHI) effect. The decrease in evapotranspiration or the increase in sensible heat caused by urbanization is considered to be the main cause of the UHI effect, but little is known about the influence of the main factor “net radiant flux” of the urban surface heat balance. In this study, experimental observation and quantitative model simulation were used to find that with the increase of building surface area after urbanization, the direct solar radiation flux and net radiation flux on building surface areas changed significantly. In order to accurately quantify the relationship between the positive and negative effects, this study puts forward the equivalent calculation principle of “aggregation element”, which is composed of a building’s sunny face and its shadow face, and the algorithm of the contribution of the area to thermal effect. This research clarifies the greenhouse effect of a building with walls of glass windows. Research shows that when the difference between absorption rates of a concrete wall and grass is −0.21, the cooling effect is shown. In the case of concrete walls with glass windows, the difference between absorption rates of a building wall and grass is −0.11, which is also a cooling effect. The greenhouse effect value of a building with glass windows reduces the cooling effect value to 56% of the effect of a building with concrete walls. The simulation of changes in net radiant flux and flux density shows that the greenhouse effect of a 5-story building with windows yields 15.5% less cooling effect than one with concrete walls, and a 30-story building with windows reduces the cooling effect by 23.0%. The simulation results confirmed that the difference in the equivalent absorption rate of the aggregation element is the “director” of cooling and heating effects, and the area of the aggregation element is the “amplifier” of cooling and heating effects. At the same time, the simulation results prove the greenhouse effect of glass windows, which significantly reduces the cold effect of concrete wall buildings. The model reveals the real contribution of optimized urban design to mitigating UHI and building a comfortable environment where there is no atmospheric circulation.
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- 2021
18. Detection of meteorological stations' underlying surface change based on RS and analysis of its influence on air temperature change in China.
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Chaoyang Sun, Quanqin Shao, Jiyuan Liu 0001, and Wenhui Kuang
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- 2010
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19. Methods to extract impervious surface areas from satellite images.
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Dengsheng Lu, Guiying Li, Wenhui Kuang, and Emilio Moran
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- 2014
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20. Comparison of Changes in Urban Land Use/Cover and Efficiency of Megaregions in China from 1980 to 2015.
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Shu Zhang, Chuanglin Fang, Wenhui Kuang, and Fengyun Sun
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- 2019
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21. City-Level Comparison of Urban Land-Cover Configurations from 2000-2015 across 65 Countries within the Global Belt and Road.
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Tao Pan, Wenhui Kuang, Rafiq Hamdi, Chi Zhang 0011, Shu Zhang, Zhili Li, and Xin Chen
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- 2019
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22. A 30-meter resolution dataset of impervious surface area and green space fractions of China's cities, 2000-2018
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Wenhui, Kuang, Shu, Zhang, Xiaoyong, Li, Dengsheng, Lu, and Wenhui Kuang
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Land use ,Urban land ,Remote Sensing ,Green Space ,Impervious Surface Area ,GIS - Abstract
1. This is the dataset described by the data paper "A national urban land use/cover change dataset in China, 2000-2018" submitted to Earth System Science Data (ESSD). 2. The dataset includes the following subsets, i.e. urban boundary (named as "Urban_Year.tif", like "Urban_2000.tif"), urban green space fraction (named as "UGS_Year_Province.tif", like "UGS_2000_Anhui.tif"), urban impervious surface area fraction (named as "UISA_Year_Province.tif", like "UISA_2000_Anhui.tif"). 3. The urban impervious surface area and urban green space datasets are showed by the percentage in a grid. In order for data storage, the data were amplified by 1000 times and converted into integer storage. 4. The detail information of datasets is listed in description.xlsx 5. Some sample mapping were listed in Samples.zip. 6. If you have any questions, please contact Wenhui Kuang (kuangwh@igsnrr.ac.cn). Related publications with this dataset. (1) Kuang W H. 70 years of urban expansion across China: Trajectory, pattern, and national policies. Science Bulletin. 2020. https://doi.org/10.1016/j.scib.2020.07.005 (2) Kuang W H, Dou Y Y. Investigating the Patterns and Dynamics of Urban Green Space in China's 70 Major Cities Using Satellite Remote Sensing. Remote Sensing. 2020, 12, 1929; doi:10.3390/rs12121929 (3) Kuang W H. Mapping global impervious surface area and green space within urban environments. Science China Earth Sciences. 2019, 62(10), 1591-1606. (4) Kuang W H. National urban land-use/cover change since the beginning of the 21st century and its policy implications in China. Land Use Policy. 2020. https:// doi.org/10.1016/j.landusepol.2020.104747, {"references":["Kuang W H. 70 years of urban expansion across China: Trajectory, pattern, and national policies. Science Bulletin. 2020. https://doi.org/10.1016/j.scib.2020.07.005","Kuang W H, Dou Y Y. Investigating the Patterns and Dynamics of Urban Green Space in China's 70 Major Cities Using Satellite Remote Sensing. Remote Sensing. 2020, 12, 1929; doi:10.3390/rs12121929","Kuang W H. Mapping global impervious surface area and green space within urban environments. Science China Earth Sciences. 2019, 62(10), 1591-1606.","Kuang W H. National urban land-use/cover change since the beginning of the 21st century and its policy implications in China. Land Use Policy. 2020. https:// doi.org/10.1016/j.landusepol.2020.104747","Kuang W H, Liu A L, Dou Y Y, et al. Examining the impacts of urbanization on surface radiation using Landsat imagery. GIScience & Remote Sensing. 2019, 56(3): 462-484.","Kuang W H. New Evidences on Anomalous Phenomenon of Buildings in Regulating Urban Climate from Observations in Beijing, China. Earth and Space Science. 2019, 6(5): 861-872."]}
- Published
- 2020
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23. 70 years of urban expansion across China: trajectory, pattern, and national policies
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Wenhui Kuang
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Multidisciplinary ,Geography ,Trajectory pattern ,Economic geography ,China ,Urban expansion - Published
- 2020
24. Time Tracking of Different Cropping Patterns Using Landsat Images under Different Agricultural Systems during 1990–2050 in Cold China
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Tao Pan, Chi Zhang, Wenhui Kuang, Philippe De Maeyer, Alishir Kurban, Rafiq Hamdi, and Guoming Du
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tracking cropping patterns ,time series images ,updating technology ,agricultural systems ,Cold China ,Science - Abstract
Rapid cropland reclamation is underway in Cold China in response to increases in food demand, while the lack analyses of time series cropping pattern mappings limits our understanding of the acute transformation process of cropland structure and associated environmental effects. The Cold China contains different agricultural systems (state and private farming), and such systems could lead to different cropping patterns. So far, such changes have not been revealed yet. Based on the Landsat images, this study tracked cropping information in five-year increments (1990–1995, 1995–2000, 2000–2005, 2005–2010, and 2010–2015) and predicted future patterns for the period of 2020–2050 under different agricultural systems using developed method for determining cropland patterns. The following results were obtained: The available time series of Landsat images in Cold China met the requirements for long-term cropping pattern studies, and the developed method exhibited high accuracy (over 91%) and obtained precise spatial information. A new satellite evidence was observed that cropping patterns significantly differed between the two farm types, with paddy field in state farming expanding at a faster rate (from 2.66 to 68.56%) than those in private farming (from 10.12 to 34.98%). More than 70% of paddy expansion was attributed to the transformation of upland crop in each period at the pixel level, which led to a greater loss of upland crop in state farming than private farming (9505.66 km2 vs. 2840.29 km2) during 1990–2015. Rapid cropland reclamation is projected to stagnate in 2020, while paddy expansion will continue until 2040 primarily in private farming in Cold China. This study provides new evidence for different land use change pattern mechanisms between different agricultural systems, and the results have significant implications for understanding and guiding agricultural system development.
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- 2018
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25. Two dimensional large-scale optical manipulation of microparticles by circular Airy beams with spherical and oblique wavefronts
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Qian Shou, Wenhui Kuang, Minghan Liu, Zhuohong Zhou, Zhichao Chen, Wei Hu, and Qi Guo
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Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Published
- 2022
26. Typical urban agglomeration and megacities urban expansion in 2000-2020
- Author
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Wenhui, Kuang
- Subjects
Urban agglomeration ,Megacities ,urban land ,Urban land expansion ,Remote Sensing ,GIS - Abstract
1. This is the dataset described by the report "Global Urban Land Cover Changes in 2000-2020" submitted to Global Ecosystem and Environment Observation Analysis Research Cooperation (GEOARC). 2. The dataset includes the following subsets, i.e. urban agglomeration urban boundary, megacities urban boundary.See the description document for details. 3. The detail information of datasets is listed in Description.xlsx 4. If you have any questions, please contact Wenhui Kuang (kuangwh@igsnrr.ac.cn). 5.Related publications with this dataset. (1)Kuang W H, Du G M, Lu D S, et al. Global observation of urban expansion and land-cover dynamics using satellite big-data. Science Bulletin. 2021, 66(4): 297-300. (2)Kuang W H, Zhang S, Li X Y, et al. A 30 m resolution dataset of China’s urban impervious surface area and green space, 2000–2018. Earth System Science Data. 2021, 13(1): 63-82. (3) Kuang W H. 70 years of urban expansion across China: trajectory, pattern, and national policies. Science Bulletin. 2020, 65(23): 1970-7974. (4) Kuang W H, Dou Y Y. Investigating the patterns and dynamics of urban green space in China’s 70 major cities using satellite remote sensing. Remote Sensing. 2020, 12(12): 1929. (5) Kuang W H. National urban land-use cover change since the beginning of the 21st century and its policy implications in China. Land Use Policy. 2020, 97: 104747. (6) Kuang W H. Mapping global impervious surface area and green space within urban environments. Science China Earth Sciences. 2019, 62(10): 1591-1606. (7) Dou Y Y, Kuang W H. A comparative analysis of urban impervious surface and green space and their dynamics among 318 different size cities in China in the past 25 years. Science of the Total Environment. 2020, 706:135828. (8) Zhang S, Fang C L, Kuang W H, et al. Comparison of changes in urban land use/cover and efficiency of megaregions in China from 1980 to 2015. Remote Sensing. 2019, 11(15): 1834. (9) Pan T, Kuang W H, Zhang C, et al. City-level comparison of urban land-cover configurations from 2000-2015 across 65 countries within the global Belt and Road. Remote Sensing. 2019, 11(13): 1515., {"references":["Kuang W H, Du G M, Lu D S, et al. Global observation of urban expansion and land-cover dynamics using satellite big-data. Science Bulletin. 2021, 66(4): 297-300.","Kuang W H, Zhang S, Li X Y, et al. A 30 m resolution dataset of China's urban impervious surface area and green space, 2000–2018. Earth System Science Data. 2021, 13(1): 63-82.","Kuang W H. 70 years of urban expansion across China: trajectory, pattern, and national policies. Science Bulletin. 2020, 65(23): 1970-7974.","Kuang W H, Dou Y Y. Investigating the patterns and dynamics of urban green space in China's 70 major cities using satellite remote sensing. Remote Sensing. 2020, 12(12): 1929.","Kuang W H. National urban land-use cover change since the beginning of the 21st century and its policy implications in China. Land Use Policy. 2020, 97: 104747.","Kuang W H. Mapping global impervious surface area and green space within urban environments. Science China Earth Sciences. 2019, 62(10): 1591-1606.","Dou Y Y, Kuang W H. A comparative analysis of urban impervious surface and green space and their dynamics among 318 different size cities in China in the past 25 years. Science of the Total Environment. 2020, 706:135828.","Zhang S, Fang C L, Kuang W H, et al. Comparison of changes in urban land use/cover and efficiency of megaregions in China from 1980 to 2015. Remote Sensing. 2019, 11(15): 1834.","Pan T, Kuang W H, Zhang C, et al. City-level comparison of urban land-cover configurations from 2000-2015 across 65 countries within the global Belt and Road. Remote Sensing. 2019, 11(13): 1515."]}
- Published
- 2021
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27. Dataset of impervious surface area and green space fractions of global urban land in 2000-2020
- Author
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Wenhui, Kuang
- Subjects
Global urban land ,Urban land cover changes ,Green Space ,Impervious Surface Area ,Remote Sensing ,GIS - Abstract
1. This is the dataset described by the report "Global Urban Land Cover Changes in 2000-2020" submitted to Global Ecosystem and Environment Observation Analysis Research Cooperation (GEOARC). 2. The dataset includes the following subsets, i.e. global impervious surface area fraction (named as "GISA_Year_Continent.tif", like "GISA_2000_Africa.tif"), global urban green space fraction (named as "GUGS_Year_Continent.tif", like "GUGS_2000_Africa.tif"), See the description document for details. 3. The global impervious surface area and global urban green space datasets are showed by the percentage in a grid. In order for data storage, the data were amplified by 100 times and converted into integer storage. 4. The detail information of datasets is listed in Description.xlsx 5. If you have any questions, please contact Wenhui Kuang (kuangwh@igsnrr.ac.cn). 6.Related publications with this dataset. (1)Kuang W H, Du G M, Lu D S, et al. Global observation of urban expansion and land-cover dynamics using satellite big-data. Science Bulletin. 2021, 66(4): 297-300. (2)Kuang W H, Zhang S, Li X Y, et al. A 30 m resolution dataset of China’s urban impervious surface area and green space, 2000–2018. Earth System Science Data. 2021, 13(1): 63-82. (3) Kuang W H. 70 years of urban expansion across China: trajectory, pattern, and national policies. Science Bulletin. 2020, 65(23): 1970-7974. (4) Kuang W H, Dou Y Y. Investigating the patterns and dynamics of urban green space in China’s 70 major cities using satellite remote sensing. Remote Sensing. 2020, 12(12): 1929. (5) Kuang W H. National urban land-use cover change since the beginning of the 21st century and its policy implications in China. Land Use Policy. 2020, 97: 104747. (6) Kuang W H. Mapping global impervious surface area and green space within urban environments. Science China Earth Sciences. 2019, 62(10): 1591-1606. (7) Dou Y Y, Kuang W H. A comparative analysis of urban impervious surface and green space and their dynamics among 318 different size cities in China in the past 25 years. Science of the Total Environment. 2020, 706:135828. (8) Zhang S, Fang C L, Kuang W H, et al. Comparison of changes in urban land use/cover and efficiency of megaregions in China from 1980 to 2015. Remote Sensing. 2019, 11(15): 1834. (9) Pan T, Kuang W H, Zhang C, et al. City-level comparison of urban land-cover configurations from 2000-2015 across 65 countries within the global Belt and Road. Remote Sensing. 2019, 11(13): 1515., {"references":["Kuang W H, Du G M, Lu D S, et al. Global observation of urban expansion and land-cover dynamics using satellite big-data. Science Bulletin. 2021, 66(4): 297-300.","Kuang W H, Zhang S, Li X Y, et al. A 30 m resolution dataset of China's urban impervious surface area and green space, 2000–2018. Earth System Science Data. 2021, 13(1): 63-82.","Kuang W H. 70 years of urban expansion across China: trajectory, pattern, and national policies. Science Bulletin. 2020, 65(23): 1970-7974.","Kuang W H, Dou Y Y. Investigating the patterns and dynamics of urban green space in China's 70 major cities using satellite remote sensing. Remote Sensing. 2020, 12(12): 1929.","Kuang W H. National urban land-use cover change since the beginning of the 21st century and its policy implications in China. Land Use Policy. 2020, 97: 104747.","Kuang W H. Mapping global impervious surface area and green space within urban environments. Science China Earth Sciences. 2019, 62(10): 1591-1606.","Dou Y Y, Kuang W H. A comparative analysis of urban impervious surface and green space and their dynamics among 318 different size cities in China in the past 25 years. Science of the Total Environment. 2020, 706:135828.","Zhang S, Fang C L, Kuang W H, et al. Comparison of changes in urban land use/cover and efficiency of megaregions in China from 1980 to 2015. Remote Sensing. 2019, 11(15): 1834.","Pan T, Kuang W H, Zhang C, et al. City-level comparison of urban land-cover configurations from 2000-2015 across 65 countries within the global Belt and Road. Remote Sensing. 2019, 11(13): 1515."]}
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- 2021
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28. Dataset of global urban expansion in 2000-2020
- Author
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Wenhui, Kuang
- Subjects
Global urban land ,urban expansion ,Remote Sensing ,GIS - Abstract
1. This is the dataset described by the report "Global Urban Land Cover Changes in 2000-2020" submitted to Global Ecosystem and Environment Observation Analysis Research Cooperation (GEOARC). 2. The dataset includes the following subsets, i.e. global urban boundary (named as "GUB_Year_Continent.tif", like "GUB_2000_Africa.tif").See the description document for details. 3. The detail information of datasets is listed in Description.xlsx 4. If you have any questions, please contact Wenhui Kuang (kuangwh@igsnrr.ac.cn). 5.Related publications with this dataset. (1)Kuang W H, Du G M, Lu D S, et al. Global observation of urban expansion and land-cover dynamics using satellite big-data. Science Bulletin. 2021, 66(4): 297-300. (2)Kuang W H, Zhang S, Li X Y, et al. A 30 m resolution dataset of China’s urban impervious surface area and green space, 2000–2018. Earth System Science Data. 2021, 13(1): 63-82. (3) Kuang W H. 70 years of urban expansion across China: trajectory, pattern, and national policies. Science Bulletin. 2020, 65(23): 1970-7974. (4) Kuang W H, Dou Y Y. Investigating the patterns and dynamics of urban green space in China’s 70 major cities using satellite remote sensing. Remote Sensing. 2020, 12(12): 1929. (5) Kuang W H. National urban land-use cover change since the beginning of the 21st century and its policy implications in China. Land Use Policy. 2020, 97: 104747. (6) Kuang W H. Mapping global impervious surface area and green space within urban environments. Science China Earth Sciences. 2019, 62(10): 1591-1606. (7) Dou Y Y, Kuang W H. A comparative analysis of urban impervious surface and green space and their dynamics among 318 different size cities in China in the past 25 years. Science of the Total Environment. 2020, 706:135828. (8) Zhang S, Fang C L, Kuang W H, et al. Comparison of changes in urban land use/cover and efficiency of megaregions in China from 1980 to 2015. Remote Sensing. 2019, 11(15): 1834. (9) Pan T, Kuang W H, Zhang C, et al. City-level comparison of urban land-cover configurations from 2000-2015 across 65 countries within the global Belt and Road. Remote Sensing. 2019, 11(13): 1515., {"references":["Kuang W H, Du G M, Lu D S, et al. Global observation of urban expansion and land-cover dynamics using satellite big-data. Science Bulletin. 2021, 66(4): 297-300.","Kuang W H, Zhang S, Li X Y, et al. A 30 m resolution dataset of China's urban impervious surface area and green space, 2000–2018. Earth System Science Data. 2021, 13(1): 63-82.","Kuang W H. 70 years of urban expansion across China: trajectory, pattern, and national policies. Science Bulletin. 2020, 65(23): 1970-7974.","Kuang W H, Dou Y Y. Investigating the patterns and dynamics of urban green space in China's 70 major cities using satellite remote sensing. Remote Sensing. 2020, 12(12): 1929.","Kuang W H. National urban land-use cover change since the beginning of the 21st century and its policy implications in China. Land Use Policy. 2020, 97: 104747.","Kuang W H. Mapping global impervious surface area and green space within urban environments. Science China Earth Sciences. 2019, 62(10): 1591-1606.","Dou Y Y, Kuang W H. A comparative analysis of urban impervious surface and green space and their dynamics among 318 different size cities in China in the past 25 years. Science of the Total Environment. 2020, 706:135828.","Zhang S, Fang C L, Kuang W H, et al. Comparison of changes in urban land use/cover and efficiency of megaregions in China from 1980 to 2015. Remote Sensing. 2019, 11(15): 1834.","Pan T, Kuang W H, Zhang C, et al. City-level comparison of urban land-cover configurations from 2000-2015 across 65 countries within the global Belt and Road. Remote Sensing. 2019, 11(13): 1515."]}
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- 2021
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29. Mapping impervious surface distribution in China using multi-source remotely sensed data
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Dengsheng Lu, Guiying Li, Wenhui Kuang, Wei Guo, and Longwei Li
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Impervious surface area ,010504 meteorology & atmospheric sciences ,business.industry ,0211 other engineering and technologies ,Distribution (economics) ,02 engineering and technology ,01 natural sciences ,Environmental modeling ,Impervious surface ,General Earth and Planetary Sciences ,Environmental science ,business ,Multi-source ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing - Abstract
Impervious surface area (ISA) data are required for such studies as urban environmental modeling, hydrological modeling, and socioeconomic analysis, but updating these datasets in a large area rema...
- Published
- 2020
30. Spatio-temporal characteristics of soil protection efforts of the Grain for Green Project in northern Shaanxi Province
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Wenhui Kuang, Jiyuan Liu, and Wenchao Liu
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Hydrology ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Consolidation (soil) ,05 social sciences ,0507 social and economic geography ,Grain for green ,01 natural sciences ,Grassland ,Monitoring data ,Earth and Planetary Sciences (miscellaneous) ,Erosion ,Environmental science ,Soil protection ,Arable land ,Soil conservation ,050703 geography ,0105 earth and related environmental sciences - Abstract
This paper looks at the Green for Grain Project in northern Shaanxi Province. Based on remote sensing monitoring data, this study analyzes the locations of arable land in northern Shaanxi in the years 2000, 2010 and 2013 as well as spatio-temporal changes over that period, and then incorporates data on the distribution of terraced fields to improve the input parameters of a RUSLE model and simulate and generate raster data on soil erosion for northern Shaanxi at different stages with a accuracy verification. Finally, combined with the dataset of farmland change, compared and analyzed the characteristics of soil erosion change in the converted farmland to forest (grassland) and the unconverted farmland in northern Shaanxi, so as to determine the project’s impact on soil erosion over time across the region. The results show that between 2000 and 2010, the soil erosion modulus of repur-posed farmland in northern Shaanxi decreased 22.7 t/ha, equivalent to 47.08% of the soil erosion modulus of repurposed farmland in 2000. In the same period, the soil erosion modulus of non-repurposed farmland fell 10.99 t/ha, equivalent to 28.6% of the soil erosion modulus of non-repurposed farmland in 2000. The soil erosion modulus for all types of land in northern Shaanxi decreased by an average of 14.51 t/ha between 2000 and 2010, equivalent to 41.87% of the soil erosion modulus for the entire region in 2000. This suggests that the Green for Grain Project effectively reduced the soil erosion modulus, thus helping to protect the soil. In particular, arable land that was turned into forest and grassland reduced erosion most noticeably and contributed most to soil conservation. Nevertheless, in the period 2010 to 2013, which was a period of consolidation of the Green for Grain Project, the soil erosion modulus and change in volume of soil erosion in northern Shaanxi were significantly lower than in the previous decade.
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- 2020
31. Seasonal Variation in Air Temperature and Relative Humidity on Building Areas and in Green Spaces in Beijing, China
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Wenhui Kuang
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010504 meteorology & atmospheric sciences ,Geography, Planning and Development ,Microclimate ,Thermal comfort ,Lawn ,010501 environmental sciences ,Seasonality ,Atmospheric sciences ,medicine.disease ,01 natural sciences ,Beijing ,medicine ,General Earth and Planetary Sciences ,Relative humidity ,Urban heat island ,Roof ,0105 earth and related environmental sciences - Abstract
The cooling and humidifying effects of urban parks are an essential component of city ecosystems in terms of regulating microclimates or mitigating urban heat islands (UHIs). Air temperature and relative humidity are two main factors of thermal environmental comfort and have a critical impact on the urban environmental quality of human settlements. We measured the 2-m height air temperature and relative humidity at the Beijing Olympic Park and a nearby building roof for more than 1 year to elucidate seasonal variations in air temperature and relative humidity, as well as to investigate the outdoor thermal comfort. The results showed that the lawn of the park could, on average, reduce the air temperature by (0.80±0.19)°C, and increase the relative humidity by (5.24±2.91)% relative to the values measured at the building roof during daytime. During the nighttime, the lawn of the park reduced the air temperature by (2.64±0.64)°C and increased the relative humidity by (10.77±5.20)%. The park was cooler and more humid than surrounding building area, especially in night period (more pronounced cooling with 1.84 °C). Additionally, the lawn of the park could improve outdoor thermal comfort through its cooling and humidifying effects. The level of thermal comfort in the park was higher than that around the building roof for a total of 11 days annually in which it was above one or more thermal comfort levels (average reduced human comfort index of 0.92) except during the winter.
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- 2020
32. Accuracy Assessment and Inter-Comparison of Eight Medium Resolution Forest Products on the Loess Plateau, China.
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Zhiqi Yang, Jinwei Dong, Jiyuan Liu 0001, Jun Zhai, Wenhui Kuang, Guosong Zhao, Wei Shen, Yan Zhou, Yuanwei Qin, and Xiangming Xiao
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- 2017
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33. Improving Fractional Impervious Surface Mapping Performance through Combination of DMSP-OLS and MODIS NDVI Data.
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Wei Guo, Dengsheng Lu, and Wenhui Kuang
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- 2017
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34. Urban Land-Cover Dynamics in Arid China Based on High-Resolution Urban Land Mapping Products.
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Tao Pan, Dengsheng Lu, Chi Zhang 0011, Xi Chen, Hua Shao, Wenhui Kuang, Wenfeng Chi, Zhengjia Liu, Guoming Du, and Liangzhong Cao
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- 2017
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35. Mapping global impervious surface area and green space within urban environments
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Wenhui Kuang
- Subjects
geography ,Impervious surface area ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Developing country ,Western asia ,010502 geochemistry & geophysics ,Urban area ,01 natural sciences ,Normalized Difference Vegetation Index ,General Earth and Planetary Sciences ,East Asia ,Physical geography ,Developed country ,Environmental quality ,0105 earth and related environmental sciences - Abstract
The mapping of impervious surface area (ISA) and urban green space (UGS) is essential for improving the urban environmental quality toward ecological, livable, and sustainable goals. Currently, accurate ISA and UGS products are lacking in urban areas at the global scale. This study established regression models that estimated the fraction of ISA/UGS in global 30 cities for validation using MODIS NDVI and DMSP/OLS nighttime light imageries. A global dataset of ISA and UGS fraction with a spatial resolution of 250 m×250 m was developed using the regression model, with a mean relative error of 0.19 for its ISA. The results showed the global urban area of 76.29×104 km2, which was primarily distributed in central Europe, eastern Asia, and central and eastern North America. The urban land area in North America, Europe, and Asia was 66.3×104 km2, accounting for 86.91% of the world’s urban area; the urban land area of the top 50 countries accounted for 59.32% of the total urban land area in the world. The global ISA of 45.26×104 km2 was mainly distributed in central and southern North America, eastern Asia, and Europe, as well as coastal regions around the world. The proportion of ISA situated in built-up areas on the continental scale followed the order of Africa (>70%)>South America>Oceania>Asia (>60%)>North America>Europe (>50%), and these areas were mostly in southeastern North America, southwestern Europe, and eastern and western Asia. North America, Europe, and Asia accounted for 89.44% of the world’s total UGS. The cities of developed countries in Europe and North America exposed a dramatic mosaic of ISA and UGS composites in urban construction. Therefore, the proportion of UGS is relatively high in those cities. However, in developing and underdeveloped countries, the proportion of UGS in built-up areas is relatively low, and urban environments need to be improved for livability.
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- 2019
36. Divergent changes in cropping patterns and their effects on grain production under different agro-ecosystems over high latitudes in China
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Jinwei Dong, Wenhui Kuang, Alishir Kurban, Tao Pan, Philippe De Maeyer, and Guoming Du
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China ,Environmental Engineering ,Food security ,010504 meteorology & atmospheric sciences ,Land use ,business.industry ,Agroforestry ,010501 environmental sciences ,01 natural sciences ,Pollution ,Crop Production ,Food Supply ,Agricultural land ,Agriculture ,Environmental Chemistry ,Environmental science ,Paddy field ,Ecosystem ,Land use, land-use change and forestry ,Edible Grain ,business ,Waste Management and Disposal ,Cropping ,0105 earth and related environmental sciences - Abstract
Drastic rice paddy expansion and rapid upland crop loss have occurred over high latitudes in China, which would affect national food security. Different agro-ecosystems (i.e., state farms guided by the central government for agriculture and private farms guided by individual farmers for agriculture) could lead to different agricultural land use patterns; but this topic has not been investigated, which has limited our understanding of the dynamics of cropping patterns (i.e., rice paddies and upland crops) under different agro-ecosystems and their effect on total grain production. Thus, this study examined these issues over high latitudes in China. The results showed that: the developed methodology for determining cropping patterns presented high accuracy (over 90%). Based on the cropping pattern data, first, a satellite evidence of substantial increase in rice paddies with the loss of upland crops was found, and the large-scale conversion from upland crops to rice paddies has become the principal land use changes during the period of 2000–2015. Second, the new phenomenon was observed with rice paddies in state farms expanding at faster rates (at proportions of 12.98%–70.11%) than those in private farms (4.86%–30.48%). Third, the conversion of upland crops into rice paddies contributed 10.69% of the net increase in grain, which played a significant role in ensuring food security. The study provided new evidence of different changes in cropping patterns under different agro-ecosystems, thereby affecting rice cropping pattern and total grain production. This information is important for understanding and guiding the response to food sustainability and environmental issues.
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- 2019
37. Cropland redistribution to marginal lands undermines environmental sustainability
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Yinyin Dou, Wenfeng Chi, Liqiao Liang, Rendong Li, Yali Hou, Shiqi Yang, Zherui Yin, Guoming Du, Tao Pan, Changqing Song, Dengsheng Lu, Jiyuan Liu, Hao Shi, Jinwei Dong, Wenbin Wu, Huimin Yan, Jiuchun Yang, Wenhui Kuang, Hanqin Tian, Changzhen Yan, Shixin Wu, Shuwen Zhang, Xiaoyong Li, Bao Xiang, and Rafiq Hamdi
- Subjects
Multidisciplinary ,Natural resource economics ,AcademicSubjects/SCI00010 ,irrigation water consumption ,Redistribution (cultural anthropology) ,marginal lands ,Sustainability ,Economics ,Earth Sciences ,cropland redistribution ,environmental sustainability ,wind erosion ,AcademicSubjects/MED00010 ,Research Article - Abstract
Cropland redistribution to marginal land has been reported worldwide; however, the resulting impacts on environmental sustainability have not been investigated sufficiently. Here we investigated the environmental impacts of cropland redistribution in China. As a result of urbanization-induced loss of high-quality croplands in south China (∼8.5 t ha–1), croplands expanded to marginal lands in northeast (∼4.5 t ha–1) and northwest China (∼2.9 t ha–1) during 1990–2015 to pursue food security. However, the reclamation in these low-yield and ecologically vulnerable zones considerably undermined local environmental sustainability, for example increasing wind erosion (+3.47%), irrigation water consumption (+34.42%), fertilizer use (+20.02%) and decreasing natural habitats (−3.11%). Forecasts show that further reclamation in marginal lands per current policies would exacerbate environmental costs by 2050. The future cropland security risk will be remarkably intensified because of the conflict between food production and environmental sustainability. Our research suggests that globally emerging reclamation of marginal lands should be restricted and crop yield boost should be encouraged for both food security and environmental benefits., Widespread loss of high-quality cropland induced by urbanization and increasing shift of crop production to low-quality marginal land threaten food security and environmental sustainability.
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- 2021
38. Examining Urban Impervious Surface Distribution and Its Dynamic Change in Hangzhou Metropolis.
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Longwei Li, Dengsheng Lu, and Wenhui Kuang
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- 2016
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39. Urban Land-Cover Change and Its Impact on the Ecosystem Carbon Storage in a Dryland City.
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Yan Yan, Chi Zhang 0011, Yunfeng Hu, and Wenhui Kuang
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- 2016
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40. Industrial land expansion in rural China threatens environmental securities
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Jiyuan Liu, Chi Zhang, Hanqin Tian, Jianguo Wu, and Wenhui Kuang
- Subjects
Sustainable development ,Environmental security ,Natural resource economics ,010501 environmental sciences ,01 natural sciences ,Industrialisation ,restrict ,Urbanization ,Industrial land ,Land use, land-use change and forestry ,Business ,China ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
China’s rural industrialization has been a major driver for its rapid economic growth during the recent decades, but its myriad environmental risks are yet to be fully understood. Based on a comprehensive national land-use data set, our study shows that the area of China’s rural industrial land (RIL) quadrupled during 1990–2015, reaching 39338 km2 in 2015, comparable to urbanization in magnitude but with a much greater degree of landscape fragmentation which implies stronger ecological and environmental impacts. About 91% of the protected areas in the central China were within 50 km from rural industrial land, thus exposed to industrial disturbances. Accelerated rural industrial land expansion, particularly in regions under high geo-hazard risks, led to dramatically increased environmental risks, threatening the safety and health of both rural industrial workers and residents. Moreover, negative effects from rural industrial land expansion could partially offset the crop production growth in recent decades. The underprivileged rural population in the west bears a disproportionally large share of the increased environmental risks. China urgently needs to design and implement sustainable policies to restrict and reshape its rural industrialization. This study aims to inspire policy makers and researchers to rethink the current model of industrial expansion and improve rural industrial land planning, which is important for achieving the sustainable development goals of China.
- Published
- 2020
41. Quantifying the response of surface urban heat island to urban greening in global north megacities
- Author
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Philippe De Maeyer, Xiuliang Yuan, Huili He, Piet Termonia, Wenhui Kuang, Fengqi Cui, Rafiq Hamdi, and Tao Yang
- Subjects
Daytime ,Hot Temperature ,Environmental Engineering ,Urban agglomeration ,Heat Stress Disorders ,Atmospheric sciences ,Pollution ,Cold Temperature ,Megacity ,Temperate climate ,Humans ,Environmental Chemistry ,Environmental science ,Precipitation ,Cities ,Urban heat island ,Green infrastructure ,Waste Management and Disposal ,Surface urban heat island ,Environmental Monitoring - Abstract
Urban heat island, a phenomenon that urban temperature is higher than the rural area nearby, affects directly citizens' human health and well-being. However, the cooling effect from urban green space (UGS) and the attribution of the different land processes to surface urban heat island intensity (SUHI) under different background climates remains unclear. The coarse-grained model was used to estimate summer SUHI in three different background climatic zones and for seven agglomerations (BTH, JP, LD, NAAC, NAGL, YZ, UQ). Results indicate that (1) the temperate zone had the highest daytime SUHI (0–10 °C), while the arid zone has the lowest daytime SUHI (−1–2 °C). In both temperate and cold zone, the daytime SUHI was higher than the nighttime SUHI. The SUHI in downtown was higher (more than 2 °C) than in the suburbs. (2) The increasing precipitation can enhance daytime SUHI while can weaken nighttime SUHI in all three climatic zones. The increasing temperature tends to enhance SUHI in both daytime and nighttime (exclude UQ). (3) The cooling effects of UGS in daytime SUHI were highly dependent on the background climate (cold > temperate > arid). (4) The nighttime SUHI could be effectively offset when UGSFs were greater than 0.48, 0.82, 0.97, 0.95 in NAAC, NAGL, YZ, and UQ. This article highlights the different feedback of urban green space to UHII and supports green infrastructure intervention as an effective means of reducing urban heat stress at urban agglomeration scales.
- Published
- 2021
42. A 30-meter resolution dataset of China's urban impervious surface area and green space fractions, 2000–2018
- Author
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Wenhui Kuang, Shu Zhang, Dengsheng Lu, and Xiaoyong Li
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Land use ,0211 other engineering and technologies ,02 engineering and technology ,Land cover ,Urban area ,01 natural sciences ,Normalized Difference Vegetation Index ,Urban planning ,Urbanization ,Environmental science ,Metre ,Physical geography ,China ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences - Abstract
Urban impervious surface area (UISA) and urban green space (UGS) are two core components of cities for characterizing urban environments. Although several global or national urban land use/cover products such as Globeland30 and FROM-GLC are available, they cannot effectively delineate the complex intra-urban land cover components. Here we proposed a new approach to map fractional UISA and UGS in China using Google Earth Engine (GEE) based on multiple data sources. The first step is to extract the vector boundaries of urban areas from China's Land Use/cover Dataset (CLUD). The UISA was retrieved using the logistic regression from the Landsat-derived annual maximum Normalized Difference Vegetation Index (NDVI). The UGS was developed through linear calibration between reference UGS from high spatial resolution image and the normalized NDVI. Thus, the China's UISA and UGS fraction datasets (CLUD-Urban) at 30-meter resolution are generated from 2000 to 2018. The overall accuracy of national urban areas is over 92 %. The root mean square errors of UISA and UGS fractions are 0.10 and 0.14, respectively. The datasets indicate that total urban area of China was 7.10 ×104 km2 in 2018, with average fractions of 70.70 % for UISA and 26.54 % for UGS. The UISA and UGS increased with unprecedented annual rates of 1,492.63 km2/yr and 400.43 km2/yr during 2000–2018. CLUD-Urban can enhance our understanding of urbanization impacts on ecological and urban dwellers’ environments, and can be used in such applications as urban planning, urban environmental studies and practices. The datasets can be downloaded from https://doi.org/10.5281/zenodo.3778424 (Kuang et al., 2020).
- Published
- 2020
43. Investigating the Patterns and Dynamics of Urban Green Space in China’s 70 Major Cities Using Satellite Remote Sensing
- Author
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Yinyin Dou and Wenhui Kuang
- Subjects
urban park ,China ,urban green space ,010504 meteorology & atmospheric sciences ,Urban green space ,business.industry ,Science ,Environmental resource management ,Capacity building ,010501 environmental sciences ,remote sensing ,urban ecosystem services ,01 natural sciences ,Geography ,Remote sensing (archaeology) ,Satellite remote sensing ,General Earth and Planetary Sciences ,Urban ecosystem ,Green infrastructure ,business ,City scale ,0105 earth and related environmental sciences - Abstract
Urban green space (UGS) plays a pivotal role in improving urban ecosystem services and building a livable environment for urban dwellers. However, remotely sensed investigation of UGS at city scale is facing a challenge due to the pixels’ mosaics of buildings, squares, roads and green spaces in cities. Here we developed a new algorithm to unmix the UGSF derived from Landsat TM/ETM/8 OLI using a big-data platform. The spatiotemporal patterns and dynamics of UGSs were examined for 70 major cities in China between 2000 and 2018. The results showed that the total area of UGS in these cities grew from 2780.66 km2 in 2000 to 6764.75 km2 in 2018, which more than doubled its area. As a result, the UGS area per inhabitant rose from 15.01 m2 in 2000 to 18.09 m2 in 2018. However, an uneven layout of UGS occurred among the coastal, western, northeastern and central zones. For example, the UGS percentage in newly expanded urban areas in the coastal zone rose significantly in 2000–2018, with an increase of 2.51%, compared to the decline in UGS in cities in the western zone. Therefore, the effective strategies we have developed should be adopted to show disparities and promote green infrastructure capacity building in those cities with less green space, especially in western China.
- Published
- 2020
44. Identifying Urban Flood Regulation Priority Areas in Beijing Based on an Ecosystem Services Approach
- Author
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Xiaoyong Li, Wenhui Kuang, and Fengyun Sun
- Subjects
Return period ,010504 meteorology & atmospheric sciences ,Geography, Planning and Development ,lcsh:TJ807-830 ,lcsh:Renewable energy sources ,Climate change ,urbanization ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,01 natural sciences ,Ecosystem services ,beijing ,Beijing ,Urbanization ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,Sustainable development ,lcsh:GE1-350 ,urban flood regulation ,Renewable Energy, Sustainability and the Environment ,lcsh:Environmental effects of industries and plants ,Geography ,lcsh:TD194-195 ,Water resource management ,Soil conservation ,Surface runoff ,ecosystem services - Abstract
Climate change and rapid urbanization have severe impacts on urban flood regulation ecosystem services (UFRES). Quantifying the UFRES has attracted increasing attention for urban sustainable development. However, few studies have focused on how to identify urban flood regulation priority areas. In this study, we simulated urban surface runoff by using the soil conservation services-curve number model, and quantified UFRES supply and demand by using relative indicators (i.e., runoff reduction ratio and urban vulnerability) at the subdistrict scale in Beijing, China. Then, an urban flood regulation priority index was developed by integrating UFRES demand and supply, and further used to identify priority areas. The results show that the mean runoff reduction ratio in Beijing decreased from 38.70% (for a 1-year rainfall return period) to 24.74% (for a 100-year rainfall return period). Subdistricts with low UFRES supply were mainly located in the urban central area and the southeastern zone, while subdistricts with high UFRES demand were mainly located in the urban central region. Meanwhile, places with high priority for flood regulation were mainly located in the inner city, and low priority areas were mainly located in northwestern, southwestern, and northeastern Beijing. Our results also imply that the urban flood regulation priority index is an effective indicator to identify urban flood regulation priority areas. These findings could provide urban planners with a comprehensive understanding of UFRES and scientific guidance to improve them.
- Published
- 2020
45. Large-scale rain-fed to paddy farmland conversion modified land-surface thermal properties in Cold China
- Author
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Zherui Yin, Wenhui Kuang, Tao Pan, Chi Zhang, Geping Luo, and Guoming Du
- Subjects
Irrigation ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Global warming ,Climate change ,Growing season ,010501 environmental sciences ,Sensible heat ,Atmospheric sciences ,01 natural sciences ,Pollution ,Sanjiang Plain ,Latent heat ,Environmental Chemistry ,Paddy field ,Environmental science ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
The recent acute evolution of cropland structure in Cold China could lead to rapid rice paddy expansion, potentially altering land-surface thermal processes and influencing climate. To address the issue, this study investigated the changes in cropland type, land-surface temperature (LST) and heat fluxes in the agricultural region of Cold China during 2000–2015 based on time-series of land-use data and MODIS LST product, using the split-window algorithms (SWA) model and the pixel component arranging and component algorithm (PCACA). The investigation revealed large-scale land transformation from rain-fed farmland to paddy field in Cold China during 2000–2015. Compared to the rain-fed farmland, lower LST was observed in paddy field throughout crop growing seasons, with the highest LST threshold found in June (7.17 ± 1.05 °C) and the lowest value found in August (1.04 ± 0.35 °C). The cooling effect of paddy-field ranged from 0.59 ± 0.06 °C, 0.77 ± 0.07 °C, and 1.08 ± 0.08 °C for the low-, medium-, and high-density paddies, respectively. Compared to other months, stronger cooling effect was found in May and June. Further analysis showed the conversion of a rain-fed farmland to paddy field reduced the sensible heat flux and soil heat flux by 52.94 W/m2 and 15.26 W/m2, respectively, while increased the latent heat flux and net radiation by 115.66 W/m2 and 47.34 W/m2, respectively. The findings from this study indicated the changes in cropland structure and management regime (e.g., irrigation) could profoundly modify land-surface thermal processes and local/regional climate, interfering the signals from global warming. Therefore, instrumental climate data that collected from areas experienced large-scale conversion between rain-fed and paddy farmland should be carefully screened and corrected to prevent land-use induced biases.
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- 2020
46. The state-of-the-art of urban climate change modeling and observations
- Author
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Piet Termonia, Peng Cai, François Duchêne, Geping Luo, Quang-Van Doan, Wenhui Kuang, Bert Van Schaeybroek, Rafiq Hamdi, Steven Caluwaerts, Hiroyuki Kusaka, and Huili He
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010504 meteorology & atmospheric sciences ,Urban heat island ,0207 environmental engineering ,BALANCE TEB SCHEME ,Climate change ,02 engineering and technology ,Environmental Science (miscellaneous) ,01 natural sciences ,Urban climate ,Urbanization ,11. Sustainability ,ANTHROPOGENIC HEAT ,Computers in Earth Sciences ,FUTURE CLIMATE ,020701 environmental engineering ,0105 earth and related environmental sciences ,AIR-TEMPERATURE ,BRUSSELS CAPITAL REGION ,Global and Planetary Change ,Coastal hazards ,business.industry ,Environmental resource management ,METROPOLITAN-AREA ,Modeling ,SEA-BREEZE ,Geology ,Metropolitan area ,Urban structure ,Physics and Astronomy ,LAND-USE CHANGES ,13. Climate action ,Earth and Environmental Sciences ,Environmental science ,Economic Geology ,Climate model ,Monitoring network ,NUMERICAL-SIMULATION ,business ,HEAT-ISLAND - Abstract
As an effect of climate change, cities need detailed information on urban climates at decision scale that cannot be easily delivered using current observation networks, nor global and even regional climate models. A review is presented of the recent literature and recommendations are formulated for future work. In most cities, historical observational records are too short, discontinuous, or of too poor quality to support trend analysis and climate change attribution. For climate modeling, on the other hand, specific dynamical and thermal parameterization dedicated to the exchange of water and energy between the atmosphere and the urban surfaces have to be implemented. Therefore, to fully understand how cities are impacted by climate change, it is important to have (1) simulations of the urban climate at fine spatial scales (including coastal hazards for coastal cities) integrating global climate scenarios with urban expansion and population growth scenarios and their associated uncertainty estimates, (2) urban climate observations, especially in Global South cities, and (3) spatial data of high resolution on urban structure and form, human behavior, and energy consumption.
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- 2020
47. Urban Land-Cover Change and Its Impact on the Ecosystem Carbon Storage in a Dryland City
- Author
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Yan Yan, Chi Zhang, Yunfeng Hu, and Wenhui Kuang
- Subjects
land-cover change ,ecosystem organic C ,soil organic C ,vegetation C ,Urumqi ,Science - Abstract
Lack of research into the complexity in urban land conversion, and paucity of observational data of soil organic carbon (SOC) beneath impervious surface area (ISA) limit our understanding of the urbanization effects on carbon (C) pools in dryland cities. Employing Landsat TM images acquired in 1990 and 2010, a hybrid classification method consisting of Linear Spectral Mixture Analysis and decision tree classification was applied to retrieve the land cover (water, ISA, greenspace, cropland, and remnant desert) of the largest dryland city in China—Urumqi. Based on vegetation carbon (VEGC) and SOC density data determined through field observations and literature reviews, we developed Urumqi’s C pool maps in 1990 and 2010, and assessed the urbanization impacts on ecosystem C. Our results showed that ISA tripled from 1990 to 2010 displacing remnant desert and cropland. The urban landscape, especially the greenspaces, became obviously fragmented. In 2010, more than 95% of the urban ecosystem C was SOC, 48% of which under the ISA. The city lost 19% of C stock from 1990 to 2010. About 82% of the ecosystem C loss was caused by the conversion of remnant desert and cropland into ISA, mainly in the northern city.
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- 2015
- Full Text
- View/download PDF
48. Examining the impacts of urbanization on surface radiation using Landsat imagery
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Yinyin Dou, Guiying Li, Dengsheng Lu, Wenhui Kuang, and Ailin Liu
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Haze ,010504 meteorology & atmospheric sciences ,0211 other engineering and technologies ,Longwave ,02 engineering and technology ,01 natural sciences ,Metropolitan area ,Beijing ,Climatology ,Urbanization ,General Earth and Planetary Sciences ,Environmental science ,Shortwave radiation ,Urban heat island ,Shortwave ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences - Abstract
Metropolitan Beijing is facing many environmental problems such as haze and urban heat island due to the rapid urbanization. Surface shortwave, longwave, and net radiations are key components of th...
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- 2018
49. Response to Comment from Rafiq Hamdi
- Author
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Wenhui Kuang
- Published
- 2019
50. Forage-livestock status in farms and ranches of ecological grass-animal husbandry construction and allocation model of grain-warp-feed in Hulunbuir Agricultural Reclamation Group
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Shuwen Zhang, Xiaoyong Li, Shanshan Wang, Huimin Yan, Jing Ning, Wenhui Kuang, Bing Fan, Zhengyi Bao, and Ping’an Zhang
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geography ,Multidisciplinary ,geography.geographical_feature_category ,Ecology ,business.industry ,05 social sciences ,Grassland degradation ,Forage ,Vegetation ,010501 environmental sciences ,01 natural sciences ,Grassland ,Land reclamation ,Agriculture ,0502 economics and business ,Grazing ,Environmental science ,Livestock ,business ,050203 business & management ,0105 earth and related environmental sciences - Abstract
In order to increase of husbandry production and to have a sustainable development of pastures, it is important to accelerate the construction of ecological grass-animal husbandry, to promote the grassland ecological carrying capacity and to reach the equilibrium in the grassland-livestock balance. We chose twenty-four farms and ranches in Hulunbuir Agricultural Reclamation Group as study area, satellite imagery from 500-m MODIS, 30-m Landsat, and 4-m GF-2 are used together with annual report data of farms and ranches. We mapped the spatial distribution and the status of degradation of grassland and we computed the net primary productivity (NPP) of farms and ranches in Hulunbuir Agricultural Reclamation Group, using remote sensing images as input data in a Vegetation Photosynthesis Model (VPM). We then analyzed the carrying capacity of grassland and its over-grazing degree and proposed the construction of artificial grassland mode of ecological grass-animal husbandry in farms and ranches. We found that about 66.16% of natural grassland has been subject to serious degradation in different degrees in the twenty-four farms and ranches, mainly manifested in the decline of grassland vegetation productivity and coverage. The grassland fragmentation area was about 1.55% of the total grassland area. Based on remote sensing the result that annual average grassland yield was about 34.07×104 t, ranging from 27.43×104 t in 2001 to 48.89×104 t in 2013 of farms and ranches in Hulunbuir Agricultural Reclamation Group. The actual grazing capacity was 164.19×104 sheep units while the theoretical grazing capacity was only 86.83×104 sheep units in Hulunbuir Agricultural Reclamation Group in 2015. The forage gap was 42.35×104 t and overload rate reached 89% without the consideration of the silage grass and purchased forage. The cultivated land area is 3.95×103 km2 in Hulunbuir Agricultural Reclamation Group. Converting 10% of the cultivated land area into artificial grassland could provide grass yield amounting to 5.86×103 km2 of the natural grassland, which would meet with the forage demand of livestock in Hulunbuir Agricultural Reclamation Group. The implementation of the Grain-Warp-Feed and the Grass-Crop rotation production mode, and the establishment of artificial grassland on cultivated land can improve the grassland quality, grassland-livestock balance, and reduce grassland degradation, which is critical to promoting the ability of the sustainable development of husbandry and ecological protection in pastures. As a measure of agricultural supply side reform, the strategy of transforming grain into forage aims to achieve effective allocation of resources.
- Published
- 2018
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