Effects of land use and landscape pattern on PM2.5 in Yangtze River Delta, China

2018 ◽  
Vol 9 (4) ◽  
pp. 705-713 ◽  
Author(s):  
Debin Lu ◽  
Wanliu Mao ◽  
Dongyang Yang ◽  
Jianan Zhao ◽  
Jianhua Xu
Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 804
Author(s):  
Bo Niu ◽  
Dazhuan Ge ◽  
Rui Yan ◽  
Yingyi Ma ◽  
Dongqi Sun ◽  
...  

In recent years, the impact of land-use systems on global climate change has become increasingly significant, and land-use change has become a hot issue of concern to academics, both within China and abroad. Urbanization, as an important socioeconomic factor, plays a vital role in promoting land-use transition, which also shows a significant spatial dependence on urbanization. This paper constructs a theoretical framework for the interaction relationship between urbanization and land-use transition, taking the Yangtze River Delta as an example, and measures the level of urbanization from the perspective of population urbanization, economic urbanization and social urbanization, while also evaluating the level of land-use morphologies from the perspective of dominant and recessive morphologies of land-use. We construct a PVAR model and coupled coordination model based on the calculated indexes for empirical analysis. The results show that the relationship between urbanization and land-use transition is not a simple linear relationship, but tends to be complex with the process of urbanization, and reasonable urbanization and land-use morphologies will promote further benign coupling in the system. By analyzing the interaction relationship between urbanization and land-use transition, this study enriches the study of land-use change and provides new pathways for thinking about how to promote high-quality urbanization.


2020 ◽  
Author(s):  
Gangfeng Zhang ◽  
Cesar Azorin-Molina ◽  
Xuejia Wang ◽  
Peijun Shi ◽  
Deliang Chen ◽  
...  

<p>Typhoon and windstorm induced extreme winds (e.g., daily maximum wind speed, DMWS) cause enormous economic losses and deaths in China every year, and rapid urbanization increased surface roughness might play a key role in extreme wind speed variability. Here, observed near-surface (at 10 m height) DMWS from 115 meteorological stations and combined DMSP/OLS (Defense Meteorological Satellite Program/Operational Linescan System) and NPP/VIIRS (Suomi National Polar-orbiting Partnership/Visible Infrared Imaging Radiometer Suite) nighttime light data from 1992-2016 in Yangtze River Delta, a rapidly urbanized area of China, were used to analyze the impact of urbanization on DMWS variability. Raw wind speed observations were subject to a robust quality control and homogenization protocol using the Climatol package. The stations were firstly classified into six urbanized groups by the difference of nighttime light indices of each station between 1992 and 2016. The results show that DMWS in Yangtze River Delta has significantly (p < 0.05) declined by -0.209m s<sup>-1 </sup>decade<sup>-1</sup> annually, with negative trends in most seasons, particularly in winter (-0.470 m s<sup>-1 </sup>decade<sup>-1</sup>, p < 0.05) and autumn (-0.300 m s<sup>-1 </sup>decade<sup>-1</sup>, p < 0.05), followed by spring (-0.178 m s<sup>-1 </sup>decade<sup>-1</sup>, p > 0.10), while a weak increase in summer DMWS was found (+0.002 m s<sup>-1 </sup>decade<sup>-1</sup>, p > 0.10). The stations in the highly urbanized group show a higher magnitude in the decline of annual DMWS, indicating the key role of urbanization in weakening DMWS. Further, this is confirmed by the regional climate model (RegCM4) sensitive experiments conducted with different land use and cover data, that is, DMWS in 1992 was higher in the experiment using the real land use and cover data than in the experiment using the land use and cover data in 2016.</p>


Land ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 91
Author(s):  
Jinfeng Ma ◽  
Weifeng Li ◽  
Zhao Wang ◽  
Liang He ◽  
Lijian Han

Although urban agglomerations are vital sites for national economic development, comprehensive multidimensional investigations of their performance are lacking. Accordingly, we examined land use efficiency from multiple perspectives in two of the earliest developed and most advanced urban agglomerations in China, the Beijing–Tianjin–Hebei (BTH) region and the Yangtze River Delta (YRD), using different metrics, including trans-regional drivers of the spatial allocation of construction land. We found that: (1) The land use efficiency of urban agglomerations was context dependent. Whereas it was higher in the Beijing–Tianjin–Hebei region for population density per unit area of construction land than in the Yangtze River Delta region, the opposite was true for gross domestic production. Thus, a single aspect did not fully reflect the land use efficiency of urban agglomerations. (2) The land use efficiency of the two urban agglomerations was also scale dependent, and in the Yangtze River Delta region, the use of multiple metrics induced variations between aggregate and local measures. Median values for the land use efficiency of cities within an urban agglomeration were the most representative for comparative purposes. (3) The drivers of the spatial allocation of construction land were trans-regional. At the regional scale, most topographical factors were restrictive. Major regional transport networks significantly influenced the occurrence of construction land near them. Dominant cities and urban areas within each city exerted remote effects on non-dominant cities and rural areas. In principle, the median value can be considered a promising metric for assessing an urban agglomeration’s performance. We suggest that stringent management of land use in areas located along regional rail tracks/roadways may promote sustainable land use.


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