Impact Of Urban Expansion Research Articles

The Impact of Urban Expansion on the Urban Thermal Environment: A Case Study in Nanchang, Jiangxi, China

Urban expansion has been changing the urban thermal environment. Understanding the spatial distribution and temporal trends in the urban thermal environment is important in guiding sustainable urbanization. In this study, we focused on the land use/land cover (LULC) changes and urban expansion in Nanchang city, Jiangxi province, China. The four elements in the remote sensing-based ecological index (RSEI) are heat, greenness, dryness, and wetness, which correspond to the land surface temperature (LST), NDVI, NDBSI, and WET, respectively. According to the synthetic images of the average indices, we conducted temporal trend analysis together with statistical significance test for these images. We conducted partial correlation analyses between LST and NDVI, NDVSI, as well as WET. In addition, we used the LULC maps to analyze the multi-year trends in urban expansion. Then, we superimposed the trends in daytime and nighttime LST in summer on urban expansion area to extract the LST trends at sample locations. The results showed that LULC in Nanchang has substantially changed during the study period. The areas with statistically significant trends in LST coincided with the urban expansion areas. Land cover change was the main reason for LST change in Nanchang. In particular, artificial surfaces showed the greatest increase in LST; for per 100 km2 expansion in artificial surfaces, the daytime and nighttime LST increased by 0.8 °C and 0.7 °C, respectively. Among all the study land cover types, water bodies showed the greatest differences in LST change between the daytime and nighttime. There were statistically significant correlations between increases in LST and increases in NDBSI as well as decreases in NDVI and WET. In view of the considerable impact of urban expansion on the urban thermal environment, we urge local authorities to emphasize on urban greening when carrying out urban planning and construction.

Impact of urban expansion on land surface temperature and carbon emissions using machine learning algorithms in Wuhan, China

The impact of the rapid expansion of urban land on the urban thermal environment and carbon chain has attracted widespread attention. This paper uses artificial neural network-cellular automata (ANN-CA) and long short-term memory model of the improved whale optimization algorithm (IWOA-LSTM) models to predict the changes of LULC and LST, and explores the correlation between LST and carbon emissions in Wuhan.The results show that urban land will occupy >70.05% of the central urban area, while green land and water areas will continue to decrease to varying degrees in 2030 and 2040. The area of the high temperature area (LST > 30 °C) is expanding in the urban land, while the green land and the low temperature area of the water body are gradually shrinking. The area of high temperature is expanding, and the area with LST > 30 °C accounts for 67.84% in summer, and the area with LST at 10 °C ∼ 15 °C accounts for 96.32% in winter. The fitting results of correlation regression show that there is a significant correlation between carbon emissions and LST. The R2 of linear fitting between LST and carbon emissions in summer and winter of 2000 are 0.6227 and 0.6143, respectively. The R2 of linear fitting in summer and winter is higher, both of which are >0.85 in 2010 and 2020. This research may provide new clues for future urban development and thermal environment governance and carbon emission mitigation.

Quantification of Green Space Landscape Structure for Sustainable Land Use Planning in Pasir Mas, Kelantan

Globally, the amount of green space in urban areas has significantly decreased because of fast urban expansion. Urbanization may modify the spatial structure of a landscape and have an impact on its ecological function. The research aims to quantify the landscape structure changes of green space in the years 1994, 2004, and 2014 in Pasir Mas using remote sensing, GIS and landscape ecology approach. Three satellite images were classified into five land use land cover (LULC) which are forest, agriculture area, cleared land, water bodies and built-up area. The results show that the highest percentage of area in year 1994 is forest followed by agriculture, built up area and water bodies. However, in year 2014 the percentage of land use are vice versa. In the period from 1994 to 2004, 1.92% of forest was converted into built up areas in Pasir Mas district. However, in the period of year 2004 to 2014, the percentage of forest area that has been converted into built up area is increase about 4.32%. Forest shows significance increase in the transition into agriculture area by 49.63% in the year of 1994 and 2004. For the period of year 2004 and 2014, the conversion of forest area into agriculture area also in high percentage which is 17.66%. Landscape structure changes analysis show that there are significant changes of Euclidean nearest neighbour distance (MNN) indicating that there is fragmentation and isolation between patches. Similarly, the size and shape of forest patches also decreased indicating by percentage of area (PAREA) and landscape shape index (LSI). Therefore, using remote sensing, GIS, and landscape ecology, this project will help understand the spatial structure of green space and the impact of urban expansion in Pasir Mas, Kelantan, in order to give the knowledge necessary for sustainable land use planning.

Functional diversity of farmland bees across rural-urban landscapes in a tropical megacity.

Urbanization poses a major threat to biodiversity and food security, as expanding cities, especially in the Global South, increasingly compete with natural and agricultural lands. However, the impact of urban expansion on agricultural biodiversity in tropical regions is overlooked. Here we assess how urbanization affects the functional response of farmland bees, the most important pollinators for crop production. We sampled bees across three seasons in 36 conventional vegetable-producing farms spread along an urbanization gradient in Bengaluru, an Indian megacity. We investigated how landscape and local environmental drivers affected different functional traits (sociality, nesting behavior, body size, and specialization) and functional diversity (functional dispersion) of bee communities. We found that the functional responses to urbanization were trait specific with more positive than negative effects of gray area (sealed surfaces and buildings) on species richness, functional diversity, and abundance of most functional groups. As expected, larger, solitary, cavity-nesting, and, surprisingly, specialist bees benefited from urbanization. In contrast to temperate cities, the abundance of ground nesters increased in urban areas, presumably because larger patches of bare soil were still available beside roads and buildings. However, overall bee abundance and the abundance of social bees (85% of all bees) decreased with urbanization, threatening crop pollination. Crop diversity promotes taxonomic and functional diversity of bee communities. Locally, flower resources promote the abundance of all functional groups, and natural vegetation can maintain diverse pollinator communities throughout the year, especially during the noncropping season. However, exotic plants decrease functional diversity and bee specialization. To safeguard bees and their pollination services in urban farms, we recommend (1) preserving seminatural vegetation (hedges) around cropping fields to provide nesting opportunities for aboveground nesters, (2) promoting farm-level crop diversification of beneficial crops (e.g., pulses, vegetables, and spices), (3) maintaining native natural vegetation along field margins, and (4) controlling and removing invasive exotic plants that disrupt native plant-pollinator interactions. Overall, our results suggest that urban agriculture can maintain functionally diverse bee communities and, if managed in a sustainable manner, be used to develop win-win solutions for biodiversity conservation of pollinators and food security in and around cities.

A cross-scale study on the relationship between urban expansion and ecosystem services in China

Clarifying the relationship between urban expansion and ecosystem services (ESs) is critical for sustainable management of land resources and ecosystems. However, little is known about the relationship between the two at the cross-scale (particularly at the national-provincial scale). Therefore, we conducted a systematic assessment of the spatiotemporal dynamics and the relationship between urban expansion and ESs including food production (FP), soil conservation (SC), carbon sequestration (CS), and water yield (WY) in China from 1992 to 2020 on the national-provincial scale. The results show that China's urban expansion took up a large amount of cropland, accounting for 79.35% of the newly-added built-up land. Shandong had the largest expansion scale and the highest speed, Shanghai had the most pronounced expansion intensity, and more than 50% of the provinces were dominated by outlying expansion pattern. In terms of total change, the three ESs of FP, SC, and WY increased by 286.5 × 106 t, 1893.61 × 106 t, and 8337.20 × 106 mm, respectively, and CS decreased by 683.90 × 106 Mg C. However, in the urban expansion area, FP and CS net decreased by 1757.6 × 104 t and 19,640.19 × 104 Mg C, respectively, while SC and WY net increased by 347.52 × 104 t and 20,264.11 × 104 mm, respectively. Shandong contributed the most to changes in ESs in urban expansion areas. Urban expansion was significantly negatively correlated with FP and CS with the correlation coefficients > -0.8; it was significantly positively correlated with SC and WY, with coefficients of 0.714 and 0.413, respectively, and urban expansion had a lagged effect on ESs. The impact of urban expansion on ESs had a spatial spillover effect and showed prominent spatial clustering in Anhui, Henan, and Shandong. Based on these results, we proposed urban planning countermeasures grounded in the perspective of ES improvement, which would provide policy references for the sustainable management of the ecological environment and land resources.

Spatial effects of urban expansion on air pollution and eco-efficiency: Evidence from multisource remote sensing and statistical data in China

Existing literature mainly focuses on the impact of urban expansion on air pollution, while eco-efficiency comprehensively considers the high-quality development of the economy and the environment, and can more comprehensively measure the green development of cities. This study uses multisource remote sensing and statistical data from 268 cities in China from 2008 to 2018, combined with ArcGIS analysis, super-efficiency EBM-DEA (Epsilon Based Measure-Data Envelopment Analysis), and SDM (spatial Durbin model) to explore the spatial effects of urban expansion on air pollution and eco-efficiency. The results show that the Beijing-Tianjin-Hebei and Chengdu-Chongqing urban agglomerations are the areas with the most serious air pollution, while the high-value areas of eco-efficiency are mainly concentrated in the eastern coastal areas, and the low-value areas are located in the central and western regions. During the study period, the center of gravity of air pollution and eco-efficiency shifted to the northeast. In addition, urban expansion has a significant U-shaped relationship with air pollution, and a significant inverted U-shaped relationship with eco-efficiency. Appropriate urban expansion has strong positive externalities on the direct and spillover effects of air pollution and eco-efficiency. However, excessive urban expansion has aggravated the air pollution of local cities, but it is beneficial to the air improvement of neighboring cities. Furthermore, for every 1% increase in UEI2 in provincial capital cities, air pollution decreases by 0.1705%, and eco-efficiency increases by 0.0244%. However, the western region and small and medium-sized cities should strictly control spatial expansion and achieve “smart growth".

Characterization and Quantification of Urban Expansion and Impact on Urban Planning Practice in Morogoro Municipality, Tanzania

Globally, there are extensive concerns about urban expansion. In response, urban expansion detection and assessing land use and land cover (LULC) changes have become significant methods to support decisions about suitable land resource use. The major concern with urban expansion aside from habitat destruction, is the distribution of human resources and basic needs especially to the community living in the newly settlement patches. This study applied a series of Landsat images to quantify the rate and characterise the pattern of urban expansion and assess its impact on urban planning practice over a 30 years period from (1990 to 2020). Change detection was supported by images and supervised classification method. Random Forest (RF) classification method was used to achieve imagery classification, and from classification results were validated by Kappa index of Agreement (KIA) and overall accuracy (OA) methods. To analyze these changes, we used Urban Expansion Intensity Index (UEII) landscape metrics to characterize the changes in the spatial patterns across Morogoro landscape and it’s impact of urban expansion on other types of land cover.
 The findings indicated that from 1990 to 2010 built up areas have been experiencing an increase of 3.9% to 18.1% respectively, while non-built up areas have decreased from 96.1% to 81.9% respectively within 30 years period time .Urban planning practice in 1990 to 2020 increased of planned land where by plan before development on land increase from 0.8% to 6.6% while the plan after development increase from 0.2% to 10.8% of the total urban area in the same year.
 In significant changes in urban expansion and urban planning practice experienced were highly correlated in 2010 to 2020. Based on the outcomes of this study, it is recommended that municipal authorities should consider initiatives in urban planning to reverse the existing trend of urban development in order to recover the sustainability and resilience of the urban situation. The conclusions clarified the spatial pattern of urban change and its influencing factors in Morogoro municipality over the past 30 years and could provide helpful reference for the future urban planning.

The Impact of Urban Expansion on Plant Diversity Change in Karst Regions of Southwest China

The Impact of Urban Expansion on Plant Diversity Change in Karst Regions of Southwest China

The seasonality of infections in tropical Far North Queensland, Australia: A 21-year retrospective evaluation of the seasonal patterns of six endemic pathogens.

An understanding of the seasonality of infections informs public health strategies and assists clinicians in their management of patients with undifferentiated illness. The seasonality of infections is driven by a variety of environmental and human factors; however, the role of individual climatic factors has garnered much attention. This study utilises Poisson regression models to assess the seasonality of six important infections in tropical Australia and their association with climatic factors and severe weather events over a 21-year period. Melioidosis and leptospirosis showed marked wet season predominance, while more cases of rickettsial disease and cryptococcosis were seen in cooler, drier months. Staphylococcus aureus infections were not seasonal, while influenza demonstrated inter-seasonality. The climate did not significantly change during the 21 years of the study period, but the incidence of melioidosis and rickettsial disease increased considerably, highlighting the primacy of other factors-including societal inequality, and the impact of urban expansion-in the incidence of these infections. While anthropogenic climate change poses a threat to the region-and may influence the burden of these infections in the future-this study highlights the fact that, even for seasonal diseases, other factors presently have a greater effect on disease incidence. Public health strategies must also target these broader drivers of infection if they are to be effective.

The Impact of Urban Expansion on Cooling Effects of Blue-Green Space in Central China

The Impact of Urban Expansion on Cooling Effects of Blue-Green Space in Central China

Modelling Impacts of Urban Expansion on Multiple Ecosystem Services (Mess): A Scenario-Based Approach in a Mixed Natural-Urbanized Landscape

Modelling Impacts of Urban Expansion on Multiple Ecosystem Services (Mess): A Scenario-Based Approach in a Mixed Natural-Urbanized Landscape

The impact of urban expansion in Beijing and Metropolitan Area urban heat Island from 1999 to 2019

Abstract This article is a quantitative study of the urban expansion of Beijing in the past two decades and its impact on the city’s heat island effect. The overall idea of this paper is a ‘basic fact description to phenomenon and law reveal-basic cause analysis-mechanism analysis-model simulation’. In this paper, the effects of urbanisation on warming in Beijing are deduced by nonlinear fitting method. Based on Google Earth Engine remote sensing image data within Beijing Inner Sixth Ring Road and using ArcGIS to retrieve Beijing’s surface temperature, the heat island effect intensity index is calculated. This paper quantitatively analyses the temporal and spatial distribution characteristics and development trends of Beijing’s urban heat island effect, combined with land use cover change (LUCC), Land Surface Temperature (LST), Normalised difference Vegetation Index (NDVI), Normalised difference Building Index (NDBI), which can explore the impact of surface vegetation distribution and building density on the urban heat island effect.

Impacts of Urban Expansion on the Diurnal Variations of Summer Monsoon Precipitation Over the South China Coast

AbstractThis study investigates the possible relationship between changes in monsoonal (May–June) rainfall diurnal variations over the south China coast and urban surface processes using hourly rain gage data during 1981–2014 and semi‐idealized numerical simulations. The continuous landward penetration of regional climatic rainband observed prior to urbanization is blocked by the city. The morning precipitation initiated at the coast “jumps” to the downstream area of city in the late afternoon, causing a 2 hr delay of the rainfall peak time. Simulations clearly reproduce this change by turning off/on the urban land use, and demonstrate a direct connection between the change of rainfall diurnal variations with a magnitude‐enhancing but slower‐penetrating sea breeze as well as the thermodynamic conditions modified by the city. Individual impacts of sensible heating, evapotranspiration, and friction from urban surface are examined using various sensitivity experiments. Urban sensible heat is found to act as the energy source to enhance the sea breeze and induce the asymmetric low‐level urban inflow that blocks the penetration of sea breeze and changes the rainfall location. Evapotranspiration and latent heat flux suppressed by the impervious urban surface causes a drier boundary layer and lower CAPE over the city. The “jumping” of the climatic rainband may result from the competing interaction of the dynamic and thermodynamic factors. Urban friction has little impact on the daytime rainfall, but could slow down seaward wind speed and enhance coastal convergence in the early morning if no strong urban heat island is present.

Impacts of Urban Expansion on the Urban Thermal Environment: A Case Study of Changchun, China

Impacts of Urban Expansion on the Urban Thermal Environment: A Case Study of Changchun, China

Land use optimization research based on FLUS model and ecosystem services–setting Jinan City as an example

Environment and development are essential components in the process of human development, and the limitation of land necessitates rational use. To cope with the impact of urban expansion on the environment, in this study, the idea of anti-planning is examined. The ecosystem service function is considered a limiting factor, and it determines 28.94% of the land in the study area as the core eco-land area, setting it as the non-construction area. At the same time, future land use status of the study area in 2025 is determined by planning restrictions and multiyear land use predictions, and finally, optimal allocation of land in the study area is determined by using the FLUS(Future Land Use Simulation) model. The simulation results show that the ecological security pattern and landscape index of the city are optimised, fragmentation of the landscape has decreased, and aggregation degree has increased.

Taxonomic and functional homogenization of farmland birds along an urbanization gradient in a tropical megacity.

Urbanization is a major driver of land use change and biodiversity decline. While most of the ongoing and future urbanization hotspots are located in the Global South, the impact of urban expansion on agricultural biodiversity and associated functions and services in these regions has widely been neglected. Additionally, most studies assess biodiversity responses at local scale (α-diversity), however, ecosystem functioning is strongly determined by compositional and functional turnover of communities (β-diversity) at regional scales. We investigated taxonomic and functional β-diversity of farmland birds across three seasons on 36 vegetable farms spread along a continuous urbanization gradient in Bangalore, a South Indian megacity. Increasing amount of grey area in the farm surroundings was the dominant driver affecting β-diversity and resulting in taxonomic and functional homogenization of farmland bird communities. Functional diversity losses were higher than expected from species declines (i.e., urbanization acts as an environmental filter), with particular losses of functionally important groups such as insectivores of crop pests. Moreover, urbanization reduced functional redundancy of bird communities, which may further weaken ecosystems resilience to future perturbations. Our study underscores urbanization as a major driver of taxonomic and functional homogenization of species communities in agricultural systems, potentially threatening crucial ecosystem services for food production.

Spatially heterogeneity response of ecosystem services supply and demand to urbanization in China

A deep understanding of the impact of urbanization on ecosystem service (ES) supply and demand is crucial to regional ecological management and sustainable development. The existing studies mainly focused on the various impacts of urbanization on ES supply, however, there is still a lack of comprehensive research on the spatial heterogeneity response of ES supply, demand and supply-demand ratio (i.e., surplus or deficit) to urbanization, especially at the national scale. To fill this gap, we measured the spatiotemporal changes of ES supply, demand and supply-demand ratios in China utilizing the ecological footprint model at the county scale of resolution. Additionally, the Geographical Weighted Regression (GWR) model was used to explore the spatial heterogeneity response of ES supply, demand and supply-demand ratios to different types of urbanization (i.e., population, economic and land). The results showed that areas with larger total ES demand was mainly concentrated in the Northeast Plain, Liaodong Peninsula, North China Plain, Pearl River Delta, Southeast coastal areas, and Sichuan Basin, while the northwest, northeast and north of China had the greater total ES supply. The counties with strong ES deficit were found in southeastern China, while, most counties in northwestern China were in ES surplus. Additionally, there was significant spatial heterogeneity influence of different types of urbanization on ES in China. Population urbanization in the southeast and south of China had a strong positive impact on the supply-demand ratio in 2000 and 2015, while economic urbanization in the northwest and south regions exerted a more remarkable positive influence. The greater positive impact of land urbanization on the supply-demand ratios was mostly concentrated in northwest China in 2000, and this effect also appeared in southeast China in 2015. Moreover, land urbanization presented a more direct and dominant impact on the ES supply, demand and supply-demand ratios than population and economic urbanization. The findings highlighted that we should focus on the impact of urban expansion on the ecosystem, formulating rational land use planning and optimizing urban spatial configurations, can be used to offset the ES deficit and realize regional sustainable development.

Case Study On: Impact of urban expansion on agricultural land: the case of Lalibela Town, Amhara Regional state, Ethiopia

The paper is addressing the impact of urban expansion on agricultural land in Lalibela town, Amhara regional state, Ethiopia and the most problems that occurs in the study area arereducing the amount of urban and rural agricultural lands, displacement of farmers from their agricultural land, loss of the most productive agricultural land, and land disputes.The town covers an area of 92,166 kilometer square and it is one the municipal woreda witha population of 51,328.It consists of six (6) woredas. Tools and methods include questionnaires for affected households,focus group discussion, field observation and from the municipal and agricultural development office through interview were applied to investigate on the impact of urban expansion on agricultural land. To meet the general objective, the following specific objectives were set: determining the amount of agricultural land lose caused by urban expansion andassessing the driving forces for urban expansion on agricultural land in the study area. The collected data results showed that, there were rapid conversions of agricultural land for urban use in Lalibela woreda. During the year 2011-2020 more than 1543 hectares amount of agricultural land were used for residential land use in Lalibela town. The main driving forces contributed for urban expansion on agricultural land were increase in population through rural to urban migration and natural increase in the town.There are different mechanisms to reduce losses of agricultural land due to urban expansion. Such as, vertical urban development, compact settlement, applying zoning regulation of the town, building social service at kebele level to minimize rural-urban migration, use properly family planning method, building condominium, the expansion of the town must consider agricultural land and the local government must take in to account the agricultural land to protect from urban expansion.

Impact of urban expansion on vegetation: The case of China (2000–2018)

Extensive urbanization leads to the degradation of vegetation, which aggravates the deterioration of many ecological environments. However, the research on the impact of urbanization on vegetation change mainly focuses on cities. But the research on urban agglomeration is relatively scarce. The impact of urbanization on vegetation is explored by quantifying the changes in construction land and normalized difference vegetation index (NDVI) in China's urban agglomerations from 2000 to 2018. Results showed that in China, 72.73% of the regional NDVI presented a significant increasing trend, and 2.05% of the regional NDVI presented a significant downward trend. Vegetation degradation occurred in urban areas, but there was an improvement in vegetation in the urban centers of 2000. In urban agglomerations, the shift of the center of gravity of construction land can affect the direction of the transfer of NDVI cold spots or hot spots. Urbanization intensity in most urban agglomerations was negatively correlated with vegetation cover and showed a downward trend along the intensity gradient. However, NDVI in areas covered by complete vegetation showed an upward trend. Based on these findings, we suggest that vegetation protection and restoration should be strengthened, and effective urban landscape planning should be carried out to promote vegetation greening.

Remote Sensing for Spatio-temporal Mapping of Land surface temperature and Surface Energy Fluxes in the Bouregreg-Chaouia Region of Morocco

In recent decades, the Bouregreg Chaouia region has been subject to urban growth and a reduction in agricultural land in this region, which has changed its environmental variables and made it vulnerable to climate change. This work raises the spatiotemporal monitoring of land use and certain environmental parameters (vegetation cover, albedo, surface temperature from 1987 to 2015 by exploring intelligent spatial data in the region. The remote sensing products were computed from Landsat 5 TM, Landsat 7 ETM+ and Landsat 8 Oli/TIRS images obtained during the dry seasons 1987, 2000 and 2015. The results showed a reduction in NDVI vegetation index (∼0.86 in 1987 to ∼0. 56 in 2000 to ∼ 0.54 in 2015) and with an increase in surface albedo (0.51 in 1987 to 0.52 in 2000 to 0. 69 in 2015), temperature (∼67°C in 1987 to 54°C in 2000 to 40°C in 2015) and to understand the impact of urbanization on the variation of environmental parameters, the evolution of the built-up area has been followed as a determining factor. However, it recorded 3.27% surface area in 1987 to 7.45% in 2000 to 28.18% in 2015. Indeed, the contribution of new technologies (GIS and remote sensing) is essential for better management and monitoring of the impact of urban expansion on the state of the environment. The results obtained remain so promising and highlight the contribution and feasibility of intelligent spatial data to assess the evolution of the urban environment on a large scale.