scholarly journals Air Quality and the Spatial-Temporal Differentiation of Mechanisms Underlying Chinese Urban Human Settlements

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1207
Author(s):  
Xueming Li ◽  
Songbo Li ◽  
Shenzhen Tian ◽  
Yingying Guan ◽  
He Liu
Keyword(s):  
Air Quality ◽  
Industrial Structure ◽  
Yellow River ◽  
Southern China ◽  
Science And Technology ◽  
Central China ◽  
Human Settlements ◽  
Technology Investment ◽  
Significant Difference ◽  
Urban Human Settlements

Urban air has its typical structural characteristics. With the continuous optimization of urban human settlement indicators, the key issue and single system of “air quality” in urban human settlements needs to be further discussed. Based on air conditions, this paper attempts to visually measure the spatial-temporal distribution of human settlements in 283 prefecture-level cities in China using ArcGIS and Matlab and tries to reveal the influencing mechanisms: (1) There is no significant difference between the average of the comprehensive score of human settlements in 6 years. The overall level of those in all cities decreases from 0.6581 to 0.6004 year by year, and the average level order in the seven regions of China is Southern China (0.7310) > Southwest China (0.6608) > East China (0.6515) > Northeast China (0.6496) > Northwest China (0.6049)> Central China (0.5901) > North China (0.5565). (2) The global Moran’s I index of China’s human settlements is between 0.3750–0.7345, showing a positive spatial correlation, and the comprehensive development level has the characteristics of local spatial convergence of low-value clusters in the middle and lower reaches of the Yellow River and high-value clusters in the south coast and Heilongjiang Province. (3) The spatial econometric model tests the influencing mechanism. There is a significant spatial positive correlation between science and technology investment in each city. The urbanization rate, the degree of advanced industrial structure, and the urban average elevation have a certain spatial spillover, showing a negative correlation. Science and technology investment and the degree of advanced industrial structure have the greatest impact.

scholarly journals Human Settlement Quality Evaluation Based on Air Quality in Major Cities of China

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Xueming Li ◽  
Songbo Li ◽  
Jiaji Gao ◽  
Pengfei Zhao ◽  
Hang Li
Keyword(s):  
Air Quality ◽  
Quality Index ◽  
Analysis Method ◽  
Human Settlements ◽  
Monthly Data ◽  
The North ◽  
Significant Difference ◽  
Urban Human Settlements ◽  
Spatial Analysis Method

Based on the monthly data of 12 months in 30 major cities and combined with the monthly data of the air quality index (AQI) in 30 major cities, this paper analyzed the quality of human settlements in 2015 with the ArcGIS spatial analysis method. On the basis of the quality of air in this analysis, the coupling degree of the five great systems in these human settlements was also calculated. The finding shows that (1) according to the spatial distribution of the human settlements quality index in the main cities, the quality of urban human settlements was gradually decreased from the coastal regions to northwest inland regions, presenting an overall look that the quality was high in the south and low in the north, which converged to the change of the air quality; (2) the human settlements quality index apparently changed with season variation. A significant difference was found in the fourth quarter, and the biggest deviation among cities in China was up to 0.680, while the smallest deviation in the second quarter was 0.448; and (3) on the basis of factors that influenced the quality index, related kinds of norms in the main cities were built in the five great systems of human settlements, and the evaluated coupling degree between the five systems was at the antagonistic stage.

scholarly journals Coevolution of Economic and Industrial Linkages within the Land-Sea Industrial Structure of China

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3452
Author(s):  
Xue Jin ◽  
Shiwei Zhou ◽  
Ussif Rashid Sumaila ◽  
Kedong Yin ◽  
Xinman Lv
Keyword(s):  
Industrial Development ◽  
Industrial Structure ◽  
Southern China ◽  
Relational Model ◽  
Industrial Structures ◽  
Resource Endowment ◽  
Significant Difference ◽  
Spatial Differences ◽  
Industrial Linkages ◽  
Effects Of Feedback

The joint development of continental and marine economies has become an important driving force for the upgrading of industrial structures. However, because of the differences in resource endowment and development potential, developing industrial structures and the quality of economic development are uneven among regions. In this study, the added values of three land-sea industries in the three marine economic circles of northern, eastern, and southern China, were employed to clarify the evolutionary behavior of the industrial structure of these three circles on the land and sea; the synchronization, lag, equilibrium, and dislocation of developing the industrial structure were also explored which a gray relational model based on convex judgment and gray time difference analyses were used to construct a relational model from the static and dynamic aspects of the system, and the internal and external linkages of the industrial structure of the three circles were analyzed from the perspective of industrial correlation. The results show that: (1) Correlations among the linkages of the three economic circles in the marine industrial structure, both including and without temporal and spatial differences, and the marine feedback driver, differ markedly. (2) The effects of feedback for marine industrial development from the Eastern Marine Economic Circle were stronger, whereas those of the Southern Marine Economic Circle were weak and those of the Northern Marine Economic Circle were ambiguous. (3) A significant difference was observed in the degree of coevolution among the land-sea industrial structures of these areas. The Northern Marine Economic Circle exhibited a slightly higher degree of coevolution than the other two economic circles, showing a stable trend of coevolution and wide spatial development. The eastern and southern circles displayed high degrees of coordination in developing their industrial structures. The research results provide a reference for regional adjustment and optimization of industrial structure.

scholarly journals Effects of ozone-vegetation interactions on meteorology and air quality in China using a two-way coupled land-atmosphere model

2021 ◽  
Author(s):  
Jiachen Zhu ◽  
Amos P. K. Tai ◽  
Steve Hung Lam Yim
Keyword(s):  
Air Quality ◽  
Air Temperature ◽  
Southern China ◽  
Gross Primary Production ◽  
Sensible Heat Flux ◽  
Surface Air Temperature ◽  
Central China ◽  
Area Index ◽  
South Central ◽  
Atmosphere Model

Abstract. Tropospheric ozone (O3), which is one of the most important air pollutants in China, is projected to continue to increase in the near future. O3 and vegetation closely interact with each other and such interactions may not only affect plant physiology (e.g., stomatal conductance and photosynthesis) but also influence the overlying meteorology and air quality through modifying leaf stomatal behaviors. Previous studies have highlighted China as a hotspot in terms of O3 pollution and O3 damage to vegetation. Yet, few studies have investigated the effects of O3-vegetation interactions on meteorology and air quality in China, especially in the light of recent severe O3 pollution. In this study, a two-way coupled land-atmosphere model was applied to simulate O3 damage to vegetation and the subsequent effects on meteorology and air quality in China. Our results reveal that O3 causes up to 16 % enhancement in stomatal resistance, whereby large increases are found in Henan, Hebei and Shandong provinces. O3 damage causes a more than 20 % reduction in photosynthesis rate, and at least 5 % and 20 % decrease in leaf area index (LAI) and gross primary production (GPP), respectively, and hotspot areas appear in the northeastern and southern China. The associated reduction in transpiration causes a 5–30 W m−2 decrease (increase) in latent heat (sensible heat) flux, which induces a 3 % reduction in surface relative humidity, 0.2–0.8 K increase in surface air temperature, and 40–120 m increase in boundary layer height in China. We also found that the meteorological changes further induce a 2–6 ppb increase in O3 concentration in northern and south-central China mainly due to enhanced isoprene emission following increased air temperature, demonstrating that O3-vegetation interactions can lead to a strong positive feedback that can amplify O3 pollution in China. Our findings emphasize the importance of considering the effects of O3 damage and O3-vegetation interactions in air quality simulations, with ramifications for both air quality and forest management.

scholarly journals Subtle Changes or Dramatic Perceptions of Air Pollution in Sydney during COVID-19

Environments ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 2
Author(s):  
Peter Brimblecombe ◽  
Yonghang Lai
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
New South ◽  
Human Mobility ◽  
Ground Level ◽  
Physical Reality ◽  
Social Perceptions ◽  
Search Terms ◽  
South Wales ◽  
Significant Difference

The COVID-19 pandemic made it critical to limit the spread of the disease by enforcing human isolation, restricting travel and reducing social activities. Dramatic improvements to air quality, especially NO2, have often characterised places under COVID-19 restrictions. Air pollution measurements in Sydney in April 2019 and during the lockdown period in April 2020 show reduced daily averaged NO2 concentrations: 8.52 ± 1.92 and 7.85 ± 2.92 ppb, though not significantly so (p1~0.15) and PM2.5 8.91 ± 4.94 and 7.95 ± 2.64 µg m−3, again a non-significant difference (p1~0.18). Satellite imagery suggests changes that parallel those at ground level, but the column densities averaged over space and time, in false-colour, are more dramatic. Changed human mobility could be traced in increasing times spent at home, assessed from Google Mobility Reports and mirrored in decreased traffic flow on a major road, suggesting compliance with the restrictions. Electricity demand for the State of New South Wales was low under lockdown in early April 2020, but it recovered rapidly. Analysis of the uses of search terms: bushfires, air quality, haze and air pollution using Google Trends showed strong links between bushfires and pollution-related terms. The smoke from bushfires in late 2019 may well have added to the general impression of improved air quality during lockdown, despite only modest changes in the ground level measurements. This gives hints that successful regulation of air quality requires maintaining a delicate balance between our social perceptions and the physical reality.

scholarly journals Urinary stone composition analysis and clinical characterization of 1520 patients in central China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daling Zhang ◽  
Songchao Li ◽  
Zhengguo Zhang ◽  
Ningyang Li ◽  
Xiang Yuan ◽  
...  
Keyword(s):  
Calcium Oxalate ◽  
Urinary Stone ◽  
Geographic Region ◽  
Central China ◽  
Urinary Stones ◽  
Composition Analysis ◽  
Stone Composition ◽  
Calcium Oxalate Stones ◽  
Significant Difference ◽  
Lower Urinary

AbstractA total of 1520 patients with urinary stones from central China were collected and analysed by Fourier transform infrared spectroscopy between October 1, 2016 and December 31, 2019. For all patients, age, sex, comorbidities, stone location, laboratory examination and geographic region were collected. The most common stone component was calcium oxalate (77.5%), followed by calcium phosphate (8.7%), infection stone (7.6%), uric acid (UA) stone (5.3%)and cystine (0.9%). The males had more calcium oxalate stones (p < 0.001), while infection stone and cystine stones occurred more frequently in females (p < 0.001). The prevalence peak occurred at 41–60 years in both men and women. UA stones occurred frequently in patients with lower urinary pH (p < 0.001), while neutral urine or alkaline urine (p < 0.001) and urinary infection (p < 0.001) were more likely to be associated with infection stone stones. Patients with high levels of serum creatinine were more likely to develop UA stones (p < 0.001). The proportion of UA stones in diabetics was higher (p < 0.001), and the incidence of hypertension was higher in patients with UA stones (p < 0.001). Compared to the other types, more calcium oxalate stones were detected in the kidneys and ureters (p < 0.001), whereas struvite stones were more frequently observed in the lower urinary tract (p = 0.001). There was no significant difference in stone composition across the Qinling-Huaihe line in central China except UA stones, which were more frequently observed in patients south of the line (p < 0.001).

scholarly journals Spatial Expansion of Human Settlement during the Longshan Period (~4.5–~3.9 ka BP) and Its Hydroclimatic Contexts in the Lower Yellow River Floodplain, Eastern China

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 712
Author(s):  
Kaifeng Li ◽  
Wenhua Gao ◽  
Li Wu ◽  
Hainan Hu ◽  
Panpan Gong ◽  
...  
Keyword(s):  
Yellow River ◽  
Asian Summer Monsoon ◽  
Spatial Expansion ◽  
Human Settlement ◽  
Human Settlements ◽  
Lower Yellow River ◽  
River Floodplain ◽  
The Lower Yellow River ◽  
Asian Summer ◽  
Longshan Period

Obvious spatial expansion of human settlement occurred in the lower Yellow River floodplain during the Longshan period, but the external factors driving this expansion remain unclear. In this study, we first delineated the hydroclimatic changes at both regional and local scales within and around the lower Yellow River floodplain and then examined the relationships of human settlements with hydroclimatic settings between the pre-Longshan and Longshan periods. The results indicate that the site distribution, site density and hydroclimatic conditions exhibited significant shifts during the pre-Longshan and Longshan periods. In the pre-Longshan period, the intense East Asian summer monsoon and abundant monsoon-related precipitation caused widespread development of lakes and marshes in the lower Yellow River floodplain. As a result, the circumjacent highlands of the lower Yellow River floodplain contained concentrated human settlements. However, the persistent weakening of the East Asian summer monsoon and consequent precipitation decline, in conjunction with accelerated soil erosion due to decreasing forest vegetation and strengthening of human activities on the upstream Loess Plateau in the Longshan period, are likely to have jointly caused both shrinking and faster filling of preexisting lakes and marshes. Subsequently, a large area of arable land had been created in the lower Yellow River floodplain and thus was occupied by locally rapid increasing population, resulting in the notable spatial expansion of human settlements during the Longshan period.

Spatiotemporal pattern mining of drought in the last 40 years in China based on the SPEI index and space-time cube

2021 ◽  
Author(s):  
Dehe Xu ◽  
Qi Zhang ◽  
Yan Ding ◽  
De Zhang
Keyword(s):  
North China ◽  
Pattern Mining ◽  
Space Time ◽  
Central China ◽  
Spatiotemporal Pattern ◽  
Severe Drought ◽  
Monthly Precipitation ◽  
Hotspot Analysis ◽  
The Past ◽  
Significant Difference

AbstractDrought is a common natural disaster that greatly affects the crop yield and water supply in China. However, the spatiotemporal characteristics of drought in China are not well understood. This paper explores the spatial and temporal distributions of droughts in China over the past 40 years using multiscale standardized precipitation evapotranspiration index (SPEI) values calculated by monthly precipitation and temperature data from 612 meteorological stations in China from 1980 to 2019 and combines the space-time cube (STC), Mann-Kendall (M-K) test, emerging spatiotemporal hotspot analysis, spatiotemporal clustering and local outliers for the analysis. The results were as follows: 1) the drought frequency and STC show that there is a significant difference in the spatiotemporal distribution of drought in China, with the most severe drought in Northwest China, followed by the western part of Southwest China and the northern part of North China. 2) The emerging spatiotemporal hotspot analysis of SPEI6 over the past 40 years reveals two cold spots in subregion 4, indicating that future droughts in the region will be more severe. 3) A local outlier analysis of the multiscale SPEI yields a low-low outlier in western North China, indicating relatively more severe year-round drought in this area than in other areas. The low-high outlier in central China indicates that this region was not dry in the past and that drought will become more severe in this region in the future.

Observed and Projected Frontal Activities in East Asia

2021 ◽  
pp. 1-46
Author(s):  
Chia-Chi Wang ◽  
Huang-Hsiung Hsu ◽  
Ying-Ting Chen
Keyword(s):  
East Asia ◽  
Climate Model ◽  
Southern China ◽  
Model Performance ◽  
Moisture Flux ◽  
Central China ◽  
Cmip5 Models ◽  
The South ◽  
Front Detection ◽  
Local Moisture

AbstractAn objective front detection method is applied to ERA5, CMIP5 historical, and RCP8.5 simulations to evaluate climate model performance in simulating front frequency and understand future projections of seasonal front activities. The study area is East Asia for two natural seasons, defined as winter (December 2nd –February 14th) and spring (February 15th –May 15th), in accordance with regional circulation and precipitation patterns. Seasonal means of atmospheric circulation and thermal structures are analyzed to understand possible factors responsible for future front changes.The front location and frequency in CMIP5 historical simulations are captured reasonably. Frontal precipitation accounts for more than 30% of total precipitation over subtropical regions. Projections suggest that winter fronts will decrease over East Asia, especially over southern China. Frontal precipitation is projected to decrease for 10-30%. Front frequency increases in the South China Sea and tropical western Pacific because of more tropical moisture supply, which enhances local moisture contrasts. During spring, southern China and Taiwan will experience fewer fronts and less frontal precipitation while central China, Korea, and Japan may experience more fronts and more frontal precipitation due to moisture flux from the south that enhances 𝜽𝒘 gradients.Consensus among CMIP5 models in front frequency tendency is evaluated. The models exhibit relatively high consensus in the decreasing trend over polar and subtropical frontal zone in winter and over southern China and Taiwan in spring that may prolong the dry season. Spring front activities are crucial for water resource and risk management in the southern China and Taiwan.

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