The impact of rapid urbanization on water resources based on INLA

<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>

Rapid and unplanned urbanization of cities has been a cause of great concern world over. Increased urbanization has immensely altered the Land Use pattern of several Indian cities, thereby altering the physical properties of the land surface. The pronounced effect of urban heat island (UHI) apart from the acute stress on limited natural resources are consequences of this rapid urbanization. UHI effect manifests as unexpected rise in city temperatures when compared to their surrounding areas, thus making them unfriendly for habitation over time. The present work analyses the effect of UHI on Bhubaneswar, an Indian city undergoing rapid urbanization in recent times, utilizing land use and land cover (LULC) change data from Landsat over a 25 km radius about the city and MODIS land surface temperatures (LST) at 1 km2 spatial resolution for a period of 15 years (2000–2014). From the study, significant changes in LULC through over-exploitation of natural resources and the related spatio-temporal variations in LST has been identified as one major factor responsible for changes in the UHI effect over Bhubaneswar. Owing to rapid urbanization (83% increase in 15 years), the city has undergone major changes in LULC aggregating to a massive ~ 89% decrease in dense vegetation and ~ 83% decrease in crop fields over this time period. Analyses of the changes in the urban energy balance and resulting UHI effect across many such Indian cities undergoing rapid urban growth is quite essential for mitigating the negative impacts of urbanization for a long-term sustainability.

Urbanization induces complex interactions between socioeconomic activities and environmental changes, as reflected in the increase of Night-Time Light (NTL) and the decline of Fractional Vegetation Cover (FVC). While NTL is a key indicator of economic growth and infrastructure expansion, its concurrent association with vegetation loss exacerbates urban heat island (UHI) effects. Although substantial progress has been achieved in examining the individual impact of urbanization on land surface temperature (LST), studies investigating the simultaneous trends of NTL and FVC and their combined effect on LST remain limited.This study utilized a 20-year (2000–2020) remote-sensed dataset to investigate the spatial and temporal interactions among NTL, FVC, and LST anomalies in East Asian megacities, especially Seoul, Tokyo, Beijing, Shanghai, and Hong Kong. Trends in NTL and FVC were analyzed using the Mann-Kendall test and Sen’s slope methods, while LST anomalies were examined to evaluate relationships with NTL and FVC. The analysis specifically focused on summer months to comprehensively evaluate urban heat island effects. Furthermore, NSGA-II optimization was employed to identify the optimal NTL and FVC ranges that best capture LST trends and explore city-specific urban green space planning patterns.The results reveal distinct nonlinear relationships between night-time light, fractional vegetation cover, and land surface temperature. LST responses varied depending on the increased balance between NTL and FVC. LST showed a more moderated response in regions where NTL and FVC increased proportionally, suggesting that vegetation can partially mitigate urbanization's thermal impacts through a synergistic effect. Conversely, areas with disproportionately high NTL increases and limited FVC growth exhibited heightened LST sensitivity, reflecting the restricted capacity of vegetation to offset the thermal stress caused by rapid urban expansion.In Shanghai, rapid urbanization has resulted in a substantial increase in land surface temperature (LST), underscoring the city's heightened vulnerability to urban development. In contrast, both Seoul and Shanghai exhibited more moderate declines in LST in areas where urban green space initiatives were implemented. However, despite Shanghai's extensive urbanization, the expansion of urban green spaces, as quantified by the rate of change in the Fraction of Vegetation Cover (FVC), has been comparatively limited relative to other cities. Furthermore, over the past 20 years, the frequency of FVC and NTL increases demonstrated a more substantial correlation with LST increases than the intensity. These findings highlight the pronounced spatiotemporal heterogeneity in urban environments, emphasizing disparities in environmental stress and recovery potential driven by varying interactions between NTL and FVC.This research suggests key indicators, such as the balance between NTL and FVC, to guide the development of cooling strategies in urban planning. The findings highlight the potential of integrating vegetation restoration into urban planning as a critical approach to achieving global sustainability goals, particularly SDG 11 (sustainable cities and communities) and SDG 13 (climate action).

AN ASSESSMENT OF SPATIAL VARIATION OF LAND SURFACE CHARACTERISTICS OF MINNA, NIGER STATE NIGERIA FOR SUSTAINABLE URBANIZATION USING GEOSPATIAL TECHNIQUES

Water resources of water transfer projects are not only used to solve the water scarcity problem in the water-receiving area but also to change the regional carbon absorption capacity. Using the water-receiving area of the Jiangsu-Shandong section of the East Route of the South-to-North Water Diversion Project (ER-SNWDP) of China as a case study, this study explored the dynamic variation in carbon stocks in response to water diversion project in the context of carbon neutrality. The results showed that (1) After the ER-SNWDP came into operation, there was a trend of growth in water area. Based on multi-scenario simulation, under the ER-SNWDP scenario, built-up land expansion would be curbed, forest and grassland reductions would be alleviated, and water areas would increase significantly compared to the natural variation scenario. (2) Due to the implementation of the project, the research area had better carbon sequestration capacity. Under the natural variation scenario from 2015 to 2025, the carbon stock would decrease by 1228.35 × 104 t. However, under the ER-SNWDP scenario, there would be an increase of 262.84 × 104 t. In addition, the water resource allocation of ER-SNWDP may affect the spatial distribution of carbon stocks. In the northeast region, particularly in the Binzhou and Dongying areas with large water transfer volumes, the increase in carbon stocks was significant, and the center of gravity of increase also tended to tilt these areas. (3) Land use had the highest explanatory power and driving force for spatial variation in carbon stocks. According to the results of the interaction factor analysis, the strongest interaction factor after 2005 was “land use ∩ nighttime lights”, indicating that the interaction between socio-economic factors and land use factors gradually amplified the impact on the spatial variation of carbon stocks. This study provides a scientific basis for future land use planning, promotes the rational and optimal allocation of water and carbon resources, and provides a prospective reference for water resources to cope with climate change and achieve carbon neutrality.

Urban land intensive use meets the requirements for the sustainable development of urban land and is an important part of urban sustainable development. The Yangtze River Economic Belt (YREB) spans the three major regions of China, which are the most active areas of China’s economy. The contradiction between humans and land is becoming more acute. There are also regional differences in land use patterns affecting the coordinated development of the YREB and the construction of an ecological civilization. Therefore, the scientific evaluation of urban land intensive use is a key area in the current research field of urban sustainable development. In this study, the YREB is chosen as the research object, and urban land intensive use is studied using nighttime light data and statistical data on the urban built-up area. An evaluation model based on urban nighttime light intensity and land urbanization is constructed with an allometric growth model. Considering that the impact of land urbanization on urban nighttime light has a possible lag effect, an evaluation model of land intensive use that considers the lag effect between urban nighttime light and the land urbanization level is proposed. Using urban agglomerations and some typical cities in the study area as research samples, the characteristics of urban nighttime light and land urbanization are analyzed to reveal the spatial and temporal characteristics of land development in the YREB. The results show that nighttime light remote-sensing data can better reflect the level of urban land use, the allometric growth model can better fit the intensity of urban light and the land urbanization level, and the allometric growth characteristics can reflect the land use characteristics of different cities and urban agglomerations. In regional experiments with typical cities and with urban agglomerations, compared to the original allometric growth model, the goodness of fit of the allometric growth model with the lag effect improves, on average, by 3.2% and 2%, respectively, with the highest increases being by 9.9% and 4.9%, respectively. The level of intensive land use in the YREB gradually decreases from east to west, and there are great differences among different cities in the provinces and urban agglomerations. The lower reaches of the Yangtze River have high land intensive use on the whole. In the middle reaches, multicenter cities have a greater efficiency of land use than the surrounding cities. In the upper reaches, only Chengdu and Chongqing have clear advantages in urban land intensive use. The results of this study can be helpful in providing an important reference for the sustainable development of land in the YREB and can provide a basis for future urban land optimization and sustainable development. Realizing the coordination and linkage between key cities and major cities is the key to enhancing the overall sustainable development ability of the core cities in the YREB.

Rapid urbanization has triggered significant changes in urban land surface temperature (LST), which in turn affects urban ecosystems and the health of residents. Therefore, exploring the interrelationship between urban development and LST can help optimize the urban thermal environment and promote sustainable development. Based on remote sensing data from 2004–2019 within the sixth ring road of Beijing, this study investigates the spatiotemporal coupling law of night time light (NTL) and LST using an overall coupling model and analyzes the degree of coordination between them using a coordination model. The spatial response law between them was also analyzed using standard deviation ellipses and bivariate spatial autocorrelation. The results show that, from the perspective of spatiotemporal evolution, the spatial distributions of NTL and LST within the sixth ring road of Beijing were closely related from 2004 to 2019, although the overall coupling of NTL and LST was initially decreased and then continuously increased. From the perspective of coordination types, the main types of coordination between NTL and LST deteriorated over time. The increase in LST lagged behind NTL from 2004 to 2009 (heating hysteresis type), while LST increased ahead of NTL from 2014 to 2019 (heating advance type). This suggests that urban development became less efficient, while LST increases became more significant. In terms of correlation, NTL and LST showed significant positive correlation and spatial positive correlation; the correlation coefficient first decreased significantly and then continued to increase. From 2004 to 2009, the temperature increase caused by urbanization was suppressed due to the 2008 Beijing Olympics and related ecological protection policies, resulting in a significant decrease in the correlation coefficient between NTL and LST. From 2009 to 2019, short-term measures taken by Beijing during the Olympic Games were no longer effective, and the opposition between urban development and related policies made the policies increasingly less effective, thereby increasing the correlation coefficient between NTL and LST, and the increase in LST was more significant. This will greatly affect the urban ecological environment and residents’ health and make the previous government investment to suppress the temperature increase all in vain. This study can provide theoretical and practical support for the development of thermal environment optimization schemes and LST mitigation strategies in Beijing and other cities.

River networks are the typical hydrological characteristic of the Yangtze delta plain. They have important ecological service functions and a unique landscape, which has been significantly degraded during the past 50 years. Qingpu District in Shanghai has been used as study area to develop an integrated method for riverscape assessment in floodplain areas with a dense river network. This integrated method bridges geomorgraphy, landscape, and regional planning. Indicators of sinuosity, connectivity, and circuitry have been integrated into a three-level framework, including river, intersection, and river network level. Furthermore, this method was integrated by the geographic information system method and stepwise regression to identify the riverscape response to the changes in the use of the land. The spatial and temporal changes of the riverscape and land use were calculated for each grid (3000 m×3000 m) from 1965 to 2006. The results indicated that the riverscape had been significantly degraded during the study period in terms of sinuosity, connectivity, and circuitry reducing. The land use changed significantly with more building areas and less water regions and agricultural land. Additionally, the regression results indicated that several specific land use conversion types had had strong effects on the change in the riverscape structure. Finally, according to the assessing method, we have proposed specific planning and management recommendations based on the pressure-state-response model to protect the riverscape from the impact of rapid urbanization.

Urbanization is closely associated with land use land cover (LULC) changes that correspond to land surface temperature (LST) variation and urban heat island (UHI) intensity. Major districts of Bangladesh have a large population base and commonly lack the resources to manage fast urbanization effects, so any rise in urban temperature influences the population both directly and indirectly. However, little is known about the impact of rapid urbanization on UHI intensity variations during the winter dry period in the major districts of Bangladesh. To this end, we aim to quantify spatiotemporal associations of UHI intensity during the winter period between 2000 and 2019 using remote-sensing and geo-spatial tools. Landsat-8 and Landsat-5 imageries of these major districts during the dry winter period from 2000 to 2020 were used for this purpose, with overall precision varying from 81% to 93%. The results of LULC classification and LST estimation showed the existence of multiple UHIs in all major districts, which showed upward trends, except for the Rajshahi and Rangpur districts. A substantial increase in urban expansion was observed in Barisal > 32%, Mymensingh > 18%, Dhaka > 17%, Chattogram > 14%, and Rangpur > 13%, while a significant decrease in built-up areas was noticed in Sylhet < −1.45% and Rajshahi < −3.72%. We found that large districts have greater UHIs than small districts. High UHI intensities were observed in Mymensingh > 10 °C, Chattogram > 9 °C, and Barisal > 8 °C compared to other districts due to dense population and unplanned urbanization. We identified higher LST (hotspots) zones in all districts to be increased with the urban expansion and bare land. The suburbanized strategy should prioritize the restraint of the high intensity of UHIs. A heterogeneous increase in UHI intensity over all seven districts was found, which might have potential implications for regional climate change. Our study findings will enable policymakers to reduce UHI and the climate change effect in the concerned districts.

The impact of rapid urbanization in cities on their microclimate is at present a great cause of global concern. One of the major consequences is the unexpected rise in temperatures in the cities compared to their surrounding areas, termed as the Urban Heat Island (UHI) effect. Over the past many years, several Indian cities are under severe stress owing to such extreme anomalous changes in their micro-meteorological conditions making them unfriendly for habitation. Presented here is a case study on Bhubaneswar - one such city on the east coast of India undergoing rapid urbanization in recent times. In this study, Land Surface Temperatures (LST) from MODIS Terra and Aqua instruments at 1 km2 spatial resolution along with the Land Use and Land Cover (LULC) change data from Landsat was used over a 25 km radius about the city for a 15 years' period from 2000 to 2014. Preliminary analyses indicate spatio-temporal changes in LULC to be one of the primary and significant factors responsible for changes in the UHI effect over the city. Investigations on the spatio-temporal variations in LST across the city and its relationship with vegetation cover indicate that overexploitation of various resources demanded by a fast growing population has led to significant changes in LULC patterns in the last few years. Analysis of the changes in the urban energy balance and resulting UHI effect across the city under various urban growth scenarios and different proportions of green urban area are in progress.

Temporal variations of artificial nighttime lights and their implications for urbanization in the conterminous United States, 2013–2017

Rapid urbanization is responsible for the increased vulnerability of land systems and the loss of many crucial ecosystem services. Land systems are typical complex systems comprised of different land use types which interact with each other and respond to external environment processes (such as urbanization), resulting in dynamics in land systems. This work develops a methodology approach by integrating complex networks and disruptive scenarios and applies it to a case study area (Wuhan City in China) to explore the effects of urbanization on land system structural vulnerability. The land system network topologies of Wuhan City during five time periods from 1990 to 2015 are extracted. Our results reveal that (1) the urban land expands at a higher speed than the urban population in Wuhan City; (2) the period of 2005–2010 has witnessed more land area conversions from ecological lands to urban land than other periods; (3) the land system is more vulnerable to intentional attacks on nodes with higher integrated node centrality and larger land area, such as paddy, dryland, and lake; and (4) the network efficiency of the land system would decline sharply if the area shrinkage of paddy, dryland, and lake is larger than 30%, 50%, and 20%, respectively. The results provide some insights into building a resilient urban land system, such as increasing the efficiency of existing urban land and controlling the shrinkage rate of important land use types. This study contributes to existing literature on complex networks by expanding its application in land systems, which highlight the potential of complex networks to capture the complexity, dynamics, heterogeneity, and emergent phenomena in land systems.

Potentiality of SDGSAT-1 glimmer imagery to investigate the spatial variability in nighttime lights

Rapid global urbanization has caused substantial changes in land cover and vegetation growth. Rapid urban growth in a short time has escalated the conflicts between economic development and ecological conservation, particularly in some metropolitan regions. However, the effects of rapid urbanization on vegetation have not been fully captured, especially accounting for the latest ecological development initiatives. In this study, we chose a typical urban agglomeration, the Beijing–Tianjin–Hebei (BTH) urban agglomeration in China, and analyzed the vegetation variation and the impacts of urbanization on the vegetation growth based on transferable methods, using data such as the Normalized Difference Vegetation Index (NDVI) and the nighttime light (NTL). The results indicate significantly enhanced vegetation growth in the BTH region, with a strikingly spatial pattern of greening in the northwest, and browning in the southeast from 2001 to 2018. Besides this, the results enclose most of the areas (72%) of built-up land in the BTH, which tended to brown in the process of rapid urban development, while 27% greened with increasing urbanization. This means that the vegetation’s response to urbanization shows apparent differences and geographic heterogeneity along the urbanization gradient at the urban agglomeration scale. Parts of the periphery of the metropolis and the central areas of developing cities may experience a browning trend; however, the core urban areas of urbanized metropolises demonstrate greening, rather than browning. Furthermore, this study provides solid evidence on the remarkable greening impacts of several ecological restoration projects which are currently underway, especially in ecologically fragile areas (e.g., the suburbs). The implications derived from the urban ecological development and the transferable methodology deployed in this paper facilitate the unfolding relationships between urbanization and social-ecological development. Our findings provide new insights into the interactions between vegetation dynamics and urbanization at the regional level.

Africa continues to experience serious signs of multiple crises in the context of sustainability. These crises include vulnerability to climate change, rapid urbanization, food insecurity, and many others. One crisis, that defines Africa today, is the unprecedented rapid urbanization which continues to pose a big challenge to the diminishing available resources, environmental quality and human well-being. Cities in Africa continue to experience a fast horizontal growth of settlements due to influx of people from rural areas who often settle in the economically lowest segments in urban areas. This horizontal rapid growth has eaten up land set for agriculture around cities and promoted the rapid growth of informal settlements exacerbating the impacts of climate change leading to a negative impact on agricultural production. Policies linking rapid urbanization and climate change with agricultural productivity are need. This paper explores and documents the impact of rapid urbanization on climate change policies and subsequent impact on agriculture in Africa.