scholarly journals Effects of Land Use/Cover Change On Atmospheric Humidity in Three Urban Agglomerations in The Yangtze River Economic

2021 ◽  
Author(s):  
Baoni Li ◽  
Lihua Xiong ◽  
Quan Zhang ◽  
Shilei Chen ◽  
Han Yang ◽  
...  
Keyword(s):  
Land Use ◽  
Air Temperature ◽  
Land Surface ◽  
Yangtze River ◽  
Urban Expansion ◽  
Regional Climate ◽  
Urban Land ◽  
The Yangtze River ◽  
Atmospheric Humidity ◽  
Urban Agglomerations

Abstract Land use/cover change (LUCC) affects regional climate not only through its direct changes of land surface properties, but also through its further modifications of land-atmosphere interactions. Urban land expansion is a typical case of LUCC in highly populated areas, and has been widely discussed about its impacts on regional air temperature, notably known as urban heat island (UHI) effects. Besides air temperature, atmospheric humidity, as another key variable in hydrometeorology and climate, would be inevitably affected by LUCC as well. However, the impacts of LUCC on atmospheric humidity seem to have not been investigated as much as on temperature. We examined atmospheric humidity changes by trend analyses of humidity indicators in three representative urban agglomerations in the Yangtze River Economic Belt (YREB), China during 1965-2017, and found the evident urban dry island (UDI) effects which are characterized by significant humidity decrease and vapor pressure deficit increase. In different urban cores, the severity levels of UDI are different. Furthermore, strong positive correlations between humidity and evapotranspiration, and between evapotranspiration and leaf area were detected during 2001-2017 when cities entered the accelerated stage of land expansion, indicating that LUCC affects regional climate through an ecohydrological way. We speculated that the UDI effect will not appear until urban land expands to a certain scale. Besides, the UHI effect emerged in the early stage of urban expansion, about 5 years earlier than the UDI effect, and has not performed prominently in recent years. This implies that urbanization-induced LUCC may exert a larger influence on UDI than on UHI in the current later period of urban expansion.

Urban dry island effect and its potential underlying mechanisms in the Yangtze River Delta urban agglomeration, China

2020 ◽  
Author(s):  
Baoni Li
Keyword(s):  
Yangtze River ◽  
Regional Climate ◽  
Yangtze River Delta ◽  
Urban Land ◽  
River Delta ◽  
Urban Agglomeration ◽  
The Yangtze River ◽  
Atmospheric Humidity ◽  
Urban Land Expansion ◽  
The Yangtze River Delta

<p>Land use/cover change (LUCC) affects regional climate change not only through its direct changes of land surface properties, but also through its further modifications of land-atmosphere interactions including the surface energy budget, water cycle and carbon cycle. Urban land expansion as a typical case of LUCC, has been widely discussed about its effects on regional climate, notably on temperature and known for urban heat island (UHI). Another important climate variable atmospheric humidity is also seriously affected by LUCC but has not earned as much attention as temperature. We examined atmospheric humidity changes by a series of indicators in the Yangtze River Delta urban agglomeration of China during 1965-2017, and found obvious urban dry land (UDI) effect in the urban cores, as characterized by decreased humidity and increased vapor pressure deficit. Furthermore, we found similar spatial patterns of humidity changes with urban land expansion process and strong correlations of humidity changes with evapotranspiration and leaf area index changes, indicating that LUCC affects regional climate through an ecohydrological way. We suggest that the UDI effect should be paid more attention in future urban planning and landscape design and more quantitative estimations of urban expansion effect on regional and global drying trends are needed.</p>

scholarly journals The Evolution of the Urban Spatial Pattern in the Yangtze River Economic Belt: Based on Multi-Source Remote Sensing Data

2018 ◽  
Vol 10 (8) ◽  
pp. 2733 ◽  
Author(s):  
Yang Li ◽  
Hua Shao ◽  
Nan Jiang ◽  
Ge Shi ◽  
Xin Cheng
Keyword(s):  
Size Distribution ◽  
Urban Areas ◽  
Yangtze River ◽  
Size Structure ◽  
Urban Land ◽  
Urban Agglomeration ◽  
Spatial Distance ◽  
The Yangtze River ◽  
Urban Agglomerations ◽  
Urban Size

The development of the Yangtze River Economic Belt (YREB) is an important national regional development strategy and a strategic engineering development system. In this study, the evolution of urban spatial patterns in the YREB from 1990 to 2010 was mapped using the nighttime stable light (NSL) data, multi-temporal urban land products, and multiple sources of geographic data by using the rank-size distribution and the Gini coefficient method. Through statistical results, we found that urban land takes on the feature of “high in the east and low in the west”. The study area included cities of different development stages and sizes. The nighttime light increased in most cities from 1992 to 2010, and the rate assumed an obvious growth tendency in the three urban agglomerations in the YREB. The results revealed that the urban size distribution of the YREB is relatively dispersed, the speed of urban development is unequal, and the trend of urban size structure shows a decentralized distribution pattern that has continuously strengthened from 1990 to 2010. Affected by factors such as geographical conditions, spatial distance, and development stage, the lower reaches of the Yangtze River have developed rapidly, the upper and middle reaches have developed large cities, and a contiguous development trend is not obvious. The evolution of urban agglomerations in the region presents a variety of spatial development characteristics. Jiangsu, Zhejiang, and Shanghai have entered a phase of urban continuation, forming a more mature interregional urban agglomeration, while the YREB inland urban agglomerations are in suburbanization and multi-centered urban areas. At this stage, the conditions for the formation of transregional urban agglomerations do not yet exist, and there are many uncertainties in the boundary and spatial structure of each urban agglomeration.

scholarly journals Examining the Relationship between Urban Land Expansion and Economic Linkage Using Coupling Analysis: A Case Study of the Yangtze River Economic Belt, China

2020 ◽  
Vol 12 (3) ◽  
pp. 1227 ◽  
Author(s):  
Bowen Chen ◽  
Changyan Wu ◽  
Xianjin Huang ◽  
Xuefeng Yang
Keyword(s):  
Land Use ◽  
Yangtze River ◽  
Spatial Relationship ◽  
Urban Land ◽  
Sustainable Land Use ◽  
Policy Implications ◽  
The Yangtze River ◽  
Negative Effects ◽  
Urban Land Expansion ◽  
The Relationship

Urban land expansion (ULE) has caused negative effects as a result of urbanization and industrialization in China in the past few decades. Strengthening economic linkage and the cooperation among regions has great implications for effectively controlling disorderly ULE and achieving sustainable and intensive land use. Previous research has rarely investigated the relationship between ULE and economic linkage. Therefore, this study analyzes the spatial patterns of ULE and economic linkage in the Yangtze River Economic Belt (YREB) of China via social network analysis and a gravity model. Moreover, the spatial relationship and coupling level between ULE and economic linkage are investigated by building a bivariate spatial autocorrelation model and a coupling coordination degree model, respectively. The results indicate that the YREB experienced rapid ULE, and the area increased from 4.24 × 104 km2 in 1990 to 7.89 × 104 km2 in 2015. The cities that experience rapid ULE have gradually transferred from the east to the west of the YREB. In addition, the economic linkage in eastern cities is evidently higher than that of western cities. Our bivariate spatial model further proves that there are strong negative spatial correlation characteristics between ULE and economic linkage. This indicates that the higher the economic linkage, the lower the speed of ULE. Moreover, the coupling coordination between ULE and economic linkage show that the overall coupling stage changed from an antagonistic stage to a running-in stage. However, the coupling coordination in the YREB presented significant spatial heterogeneity, and most cities in urban agglomeration had a relationship between ULE and economic linkage that was barely balanced, slightly unbalanced, or seriously unbalanced. By considering the limitations and obstacles of current initiatives, suggestions and policy implications for sustainable land use at large regional scales are suggested.

scholarly journals Scenario Analysis on Climate Change Impacts of Urban Land Expansion under Different Urbanization Patterns: A Case Study of Wuhan Metropolitan

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Xinli Ke ◽  
Feng Wu ◽  
Caixue Ma
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Urban Expansion ◽  
Regional Climate ◽  
Urban Land ◽  
Urban Land Use ◽  
Rapid Urbanization ◽  
Urban Land Expansion ◽  
The Impact

Urban land expansion plays an important role in climate change. It is significant to select a reasonable urban expansion pattern to mitigate the impact of urban land expansion on the regional climate in the rapid urbanization process. In this paper, taking Wuhan metropolitan as the case study area, and three urbanization patterns scenarios are designed to simulate spatial patterns of urban land expansion in the future using the Partitioned and Asynchronous Cellular Automata Model. Then, simulation results of land use are adjusted and inputted into WRF (Weather Research and Forecast) model to simulate regional climate change. The results show that: (1) warming effect is strongest under centralized urbanization while it is on the opposite under decentralized scenario; (2) the warming effect is stronger and wider in centralized urbanization scenario than in decentralized urbanization scenario; (3) the impact trends of urban land use expansion on precipitation are basically the same under different scenarios; (4) and spatial distribution of rainfall was more concentrated under centralized urbanization scenario, and there is a rainfall center of wider scope, greater intensity. Accordingly, it can be concluded that decentralized urbanization is a reasonable urbanization pattern to mitigate climate change in rapid urbanization period.

scholarly journals Measuring Multi-Faceted Land Use Efficiency of Large-Scale Urban Agglomerations under Multi-Scale Drivers: Evidence from China

Land ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 91
Author(s):  
Jinfeng Ma ◽  
Weifeng Li ◽  
Zhao Wang ◽  
Liang He ◽  
Lijian Han
Keyword(s):  
Land Use ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
Construction Land ◽  
Urban Agglomerations ◽  
Land Use Efficiency ◽  
Use Efficiency ◽  
The Yangtze River Delta

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.

scholarly journals Change Pattern and Driving Mechanism of Construction Land in China’s Undertaking Industrial Transfer Demonstration Area: Taking the Wanjiang City Belt along the Yangtze River as an Example

2020 ◽  
Vol 24 (2) ◽  
pp. 215-223
Author(s):  
Yuhong Cao ◽  
Meiyun Liu ◽  
Yuandan Cao ◽  
Chen Chen ◽  
Dapeng Zhang
Keyword(s):  
Land Use ◽  
Economic Development ◽  
Yangtze River ◽  
Urban Land ◽  
Driving Mechanism ◽  
The Yangtze River ◽  
Residential Areas ◽  
Construction Land ◽  
Industrial Transfer ◽  
Change Pattern

The construction land includes the urban land, rural residential areas and other construction land. The Wanjiang City Belt along the Yangtze River is an important demonstration area for undertaking industrial transfer in China. With the accumulation of factors relative to economic development, the construction land has increased sharply, and the regional ecological security pattern is facing new challenges. After collecting the image interpretation data of multi-period land use of the Wanjiang City Belt, the work studied the characteristics of construction land change pattern since 1995 and its driving mechanism based on the GIS platform, land use transfer matrix, expansion intensity index, hotspot analysis and mathematical statistics. The results showed that: (1) From 1995 to 2015, the urban land and other construction land in the Wanjiang City Belt have increased, but the rural residential areas decreased in 2010-2015. The three types of land had the largest changes in 2005-2010 and the change in the other construction land was particularly prominent. (2) The hotspots for construction land expansion are mainly in urban areas with rapid economic development such as Hefei, Wuhu, Ma’anshan and Tongling, where the land use changes most severely. (3) The driving factors for the change of construction land area include natural and social factors. Among social and economic factors, the GDP, industrial added value, secondary output value and urbanization rate are the main driving forces for changes. In the past 20 years, the construction of China’s Undertaking Industrial Transfer Demonstration Area has changed the land optimal allocation and intensive use mode in the region, providing the basis for resource development and utilization, economic development and industrial structure adjustment.

Gradients of Atmospheric Temperature and Humidity Controlled by Local Urban Land-Use Intensity in Boston

2017 ◽  
Vol 56 (4) ◽  
pp. 817-831 ◽  
Author(s):  
J. A. Wang ◽  
L. R. Hutyra ◽  
D. Li ◽  
M. A. Friedl
Keyword(s):  
Land Use ◽  
Air Temperature ◽  
Rural Areas ◽  
Land Surface ◽  
Growing Season ◽  
Urban Land ◽  
Urban Land Use ◽  
Heat Island ◽  
Near Surface ◽  
Urban Rural

AbstractCities are home to the majority of humanity. Therefore, understanding the mechanisms that control urban climates has substantial societal importance to a variety of sectors, including public health and energy management. In this study, data from an urban sensor network (25 stations) and moderate-resolution remote sensing were used to explore how spatial variation in near-surface air temperature Ta, vapor pressure deficit (VPD), and land surface temperature (LST) depend on local variations in urban land use, both diurnally and seasonally, in the Boston, Massachusetts, metropolitan area. Positive correlations were observed between the amount of local impervious surface area (ISA) and both Ta and VPD. Heat-island effects peaked during the growing-season nighttime, when mean Ta and VPD increased by up to 0.02°C and 0.008 kPa, respectively, per unit ISA. Air temperature and VPD were strongly coupled, but their relationship exhibited significant diurnal hysteresis during the growing season, with changes in VPD generally preceding changes in Ta. Over 79% of the urban–rural difference in VPD was explained by differences in near-surface atmospheric water content, which the authors attribute to reduced evapotranspiration from lower canopy cover in Boston’s urban core. Changes in daytime heat-island intensity were mediated by seasonal feedbacks between vegetation transpiration and VPD forcing. Differences between LST and Ta showed weaker coupling in highly urbanized areas than in rural areas, with summertime surface-urban-heat-island intensity (based on LST) being up to 14°C higher than corresponding urban–rural differences in Ta.

scholarly journals Impact of Urbanization and Land-Use Change on Surface Climate in Middle and Lower Reaches of the Yangtze River, 1988–2008

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaowei Yao ◽  
Zhanqi Wang ◽  
Hua Wang
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Yangtze River ◽  
Regional Climate ◽  
Global Environmental Change ◽  
The Yangtze River ◽  
Temperature And Precipitation ◽  
Regional Temperature ◽  
The Impact

Land-use/land cover change (LUCC) is one of the fundamental causes of global environmental change. In recent years, understanding the regional climate impact of LUCC has become a hot-discussed topic worldwide. Some studies have explored LUCC impact on regional climate in specific cities, provinces, or farming areas. However, the quick-urbanized areas, which are highly influenced by human activities, have the most severe land-use changes in developing countries, and their climatic impact cannot be ignored. This study aims to identify the impact of land-use change coupled with urbanization on regional temperature and precipitation in the metropolitan areas of middle and lower reaches of the Yangtze River in China by means of spatial analysis and numeric methods. Based on the exploration of land-use change and climate change during 1988–2008, the impact of land-use transition from non-built-up area to built-up area on temperature and precipitation was analyzed. The results indicated that the land-use conversion has affected the regional temperature with an increasing effect in the study area, while the influence on precipitation was not so significant. The results can provide useful information for spatial planning policies in consideration of regional climate change.

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