Bay Area Research Articles

Impact of Land Use/Land Cover Changes on Urban Flooding: A Case Study of the Greater Bay Area, China

Impact of Land Use/Land Cover Changes on Urban Flooding: A Case Study of the Greater Bay Area, China

A Study on the Collaborative Development Path of Technological and Financial Innovation in Guangdong-Hong Kong-Macao Greater Bay Area

Strengthening the synergistic development of science and technology finance in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) is of great significance in further promoting financial liberalization and innovation, and deepening the financial co-operation and development between the Mainland, Hong Kong and Macao. In view of the positioning and mission of the GBA, there are still a lot of areas that need to be strengthened in the synergistic development of science and technology finance among the three places. For example, there is no synergy in regional science and technology co-operation and innovation, such as differences in institutional systems, lack of science and technology and financial talents, lack of mechanisms for circulation and sharing of innovative resources, and uneven distribution of innovative advantages. Based on this, GBA needs to build a unified and efficient platform for collaborative innovation and vigorously promote the circulation of resources; strengthen innovation cooperation and cultivate a strategic engine to lead industrial development; and focus on industrial upgrading and promote institutional innovation to form a new pattern of science and technology financial cooperation.

Assessing the Bankruptcy Risks of China's Emerging Port Industries: Modeling and Early Warning

Vigorously developing emerging marine industries are an important way for China to implement the strategy of “Sea Power Nation”, and improving the ability of port enterprises to prevent financial and tax risks is a key link in accelerating the high-quality development of the marine economy. The research objective of this paper is to construct a reasonable early warning financial model for emerging port industries in Guangdong, Hong Kong, and Macao Greater Bay Area. The research hypothesis is that the original Z-SCORE model and F-SCORE model are not able to accurately predict the financial risk of emerging marine industries. The data of typical port enterprises are utilized to compare the financial risk; after that risk assessment and early warning are carried out. This paper adopts the Delphi method to assign weights to different indicators and utilizes the Analytic Hierarchy Process method to derive a financial and tax early warning model applicable to Guangdong, Hong Kong, and Macao Greater Bay Area. The results of the study found that the traditional “Z-score model” and “F-score model” are less applicable to the emerging industries in the ports of Guangdong, Hong Kong, and Macao Greater Bay Area. This paper will construct a financial and tax risk control model corresponding to the development of port emerging industries and provide early warning when exceeding a certain threshold to help enterprises develop better. In addition, this paper also puts forward policy suggestions for risk management of emerging port industries from the aspects of system improvement and government-enterprise linkage.

고고자료를 통해 본 加耶의 港市國家論

This passage examines the operation and trade patterns of port cities by analyzing the area in the Gaya where foreign elements are concentrated, through the 'Port City States Theory'. To approach the ‘Port City States Theory’ archaeologically, we first defined the concept and attempted to schematize the structure of port cities. Based on this, we were able to establish the developmental stages of ports as 'port of call, trading post, port city, port citystate.‘ As can be confirmed from historical documents and archaeological evidence, the ancient Gimhae Bay area is a region where foreign elements are concentrated. Multiple port cities, not only in the central area but also in the hinterlands, are considered to be organically combined and operated as a port city-state. In the Changnyeong and Geoje regions, a distinct way of life is observed, which can be traced back to related trading posts found in the southern Honam region and the northern part of Kyushu in Japan. It can be observed that Changwon region formed a port city based on iron production, and it appears to have continued its operation even through changes in the dominant groups. In the eastern part of Honam, there is a pattern where foreign elements are concentrated within the indigenous community, indicating that this region was likely used as a trading post due to its location along the coastal routes. After examining the changing patterns of port cities in each region over different periods, it is evident that in the 1st period (from the mid-3rd century to the early 4th century), the port cities in the Gaya region, particularly in the ancient Gimhae Bay area, were developed. In the 2nd period (from the mid-4th century to later), there was an organic combination and operation of the permanent networks in the ancient Gimhae Bay area, and port cities expanded to areas like Changnyeong, Geoje, and Changwon. In the 3rd period (from before the 5th century to the middle of the 5th century), the permanent networks in the ancient Gimhae Bay area began to shrink but continued to operate, and each region also saw a reduction in its size. In the 4th period (after the 5th century), it appears that the port city-like characteristics gradually disappeared in various regions.

Analyzing the impact of sustainable economic development from the policy text network: Based on the practice of China's bay area policy.

In order to break through the surface analysis of the content structure of policy texts, an in-depth discussion of the linkage between regional policy makers and objectives is helpful to analyze the formation mechanism of policy effects. Through social network analysis and multi-index analysis, this study takes the QianwanNew Area of Ningbo and the Guangdong-Hong Kong-Macao Greater Bay Area as representatives to explore the policy framework for the sustainable development of manufacturing industry in the two bay areas respectively. Through the construction of government department cooperation network, policy keyword co-occurrence network, department keyword correlation network, and the analysis of network density, network centrality, structural holes, and cohesive subgroups, it is found that the impact results show great differences, which is related to the network structure of manufacturing policy text.

Деревянные предметы из древнекорякского захоронения в нише на мысе Братьев, обнаруженные С. П. Ефимовым в 1976 году (залив Бабушкина, Северное Приохотье)

The relevance of studying the ancient Koryak culture of the Northern Okhotsk region is noted. A difficult problem is the study of its funeral rituals. One of the most promising sites for studying the ancient Koryak burial complexes is Cape Bratyev and Cape Bukhty Malaya Astronomicheskaya. The article discusses wooden items from the burial in the niche under a stone at Cape Bratyev in the area of Babushkin Bay. The wooden objects are identified as parts of a compound bow. The closest to Cape Bratyev bow fragments are ancient Eskimo bows. Information is provided about wooden finds at ancient Koryak sites. The presented data demonstrate the research potential of the ancient Koryak burial complexes in the Northern Priokhotye. The unsatisfactory condition of some burials, as well as natural destruction of the rock cliff and movement of boulders, among which the burials are located, determine the need for immediate research of these archaeological sites.

Metagenomic perspectives on antibiotic resistance genes in tap water: The environmental characteristic, potential mobility and health threat

As an emerging environmental contaminant, antibiotic resistance genes (ARGs) in tap water have attracted great attention. Although studies have provided ARG profiles in tap water, research on their abundance levels, composition characteristics, and potential threat is still insufficient. Here, 9 household tap water samples were collected from the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) in China. Additionally, 75 sets of environmental sample data (9 types) were downloaded from the public database. Metagenomics was then performed to explore the differences in the abundance and composition of ARGs. 221 ARG subtypes consisting of 17 types were detected in tap water. Although the ARG abundance in tap water was not significantly different from that found in drinking water plants and reservoirs, their composition varied. In tap water samples, the three most abundant classes of resistance genes were multidrug, fosfomycin and MLS (macrolide-lincosamide-streptogramin) ARGs, and their corresponding subtypes ompR, fosX and macB were also the most abundant ARG subtypes. Regarding the potential mobility, vanS had the highest abundance on plasmids and viruses, but the absence of key genes rendered resistance to vancomycin ineffective. Generally, the majority of ARGs present in tap water were those that have not been assessed and are currently not listed as high-threat level ARG families based on the World Health Organization Guideline. Although the current potential threat to human health posed by ARGs in tap water is limited, with persistent transfer and accumulation, especially in pathogens, the potential danger to human health posed by ARGs should not be ignored.

Late Holocene Climate Warming Events and Their Linkage to Hydraulic Engineering on the Coast of Hangzhou Bay, East China

The coastal lowlands in East China are very sensitive to climate change and marine disasters, and much large-scale hydraulic engineering was recorded in the historical documents of the Late Holocene. In this study, AMS 14C and OSL were used to date three sedimentary profiles from the north and south coasts of inner Hangzhou Bay, and grain size and geochemical analyses including organic carbon, macro-elements, and alkaline earth metals were performed, while hydraulic engineering records in historical documents were compiled, in an attempt to reveal the sedimentary records of extreme climatic and hydrological events over the past 3000 years and to probe into the correlation between them and hydraulic engineering. The results show that the intensified chemical weathering during ca. 200 BCE to 900 CE in East China corresponded to the warm and humid climate during the Qin-Han and Sui-Tang dynasties. Salinity intrusion with rising local water levels occurred in the lowland plains along the south coast of Hangzhou Bay from 120 to 895 CE. Low-salinity water intrusion from 32 to 488 CE was also recorded in the stratigraphy of lowland plains along the north coast of Hangzhou Bay. The sedimentary records of the East Tiaoxi River basin show river floods about 2000 years ago. The above sedimentary records indicate that the relative sea level rose in the Hangzhou Bay area during the Qin-Han and Sui-Tang Warm Periods, resulting in frequent salinity intrusion and river floods, which coincided with the historical records of hydraulic engineering such as the construction of seawalls, river levees, and the enclosure of lakes for restoration of river floods during the Han and Tang dynasties. Such coincidence reflects that climate change profoundly affected the hydrological environment of the coastal areas in East China as well as the response of the human societies.

Habitat suitability assessment for tule elk in the San Francisco Bay and Monterey Bay areas

While California’s statewide tule elk (Cervus canadensis nannodes) population has recovered from two or three individual survivors in the late 19th century, the subspecies exists today in numerous widely disjunct populations, leaving vast areas of the species’ former range uninhabited. Large unoccupied areas of historic tule elk range include the Santa Cruz Mountains and the northern Diablo and northern Santa Lucia ranges. Natural range expansion by existing populations into these areas is blocked by major highways and urban development; although, before considering tule elk translocations, it is necessary to assess the habitat suitability there. To this end, we fit a resource selection function (RSF) using generalized linear mixed models to GPS collar data collected from nearby radio collared tule elk and used several environmental GIS layers to capture important habitat characteristics. We fit the RSF in a habitat use versus availability framework with only linear and quadratic terms and used stepwise model selection ranked by AICc to maximize its generalizability, enabling transferability to our unoccupied study area. We also used k-fold cross validation to evaluate our RSF and found it predicted habitat within the San Luis Reservoir herd well. The fit habitat relationships mostly followed expectations based on tule elk ecology, including positive responses to herbaceous vegetation cover and waterbody proximity, and negative responses to high tree cover and high puma habitat suitability. Our RSF accurately predicted currently occupied elk habitat as suitable and found well over 500,000 ha (2,000 mi2) of suitable but unoccupied habitat throughout the northern Diablo Range, the inland and coastal sides of the Santa Cruz Mountains, and the northern Santa Lucia Range. Assuming translocations, and construction and improvement of highway wildlife crossings, our results support the potential for re-establishing tule elk in these regions, which are more coastal and mesic than the species’ current habitat in the central Diablo and northern Gabilan ranges.

Understanding the Dynamics of Unemployment and Poverty in the Tomini Bay Area

This study aims to analyze the effect of education level, gini ratio and labor force participation rate on unemployment, as well as the effect of unemployment on poverty in the Tomini Bay region. The data used in the study is secondary data in the form of 10 regencies/cities in the Tomini Bay area, for the 2018-2022 period, sourced from the Indonesian Central Bureau of Statistics. The novelty of this study is trying to trace the relationship between educational and economic aspects to the phenomenon of poverty in the Tomini Bay Region, as a regional economic power. The future impact of this study is the mapping of the actual condition of poverty and the availability of more evidence-based policy recommendations in reducing unemployment and poverty in the Tomini Bay Area. This study used descriptive quantitative methods. With an approach (Simultaneous equation regression model) using the Indirect Least Square (ILS) regression technique with Fixed Effect Model (FEM). The results of this study show that the level of education and the labor force participation rate have a negative and significant effect on unemployment. In contrast to the Gini ratio which actually has a positive and significant effect on unemployment. On the other hand, unemployment shows a positive and significant influence on poverty. The implication of the research is the need for a truly massive policy to strengthen the education dimension, to accelerate the increase in human capital and the importance of a sustainable program to increase employment opportunities from the government so as to reduce unemployment and poverty.

Investigation of the microscopic properties of natural structured clay

Conducting quantitative research on the microstructure of soft clay can reveal the essence of its soil mechanical behavior, which is of important practical significance for geological disaster risk assessment and prevention. To quantitatively investigate the microscopic properties of natural structured clay, soft clay soils from various sedimentary environments in the Hangzhou Estuarine Bay area were chosen as the research subject in this study. Subsequently, a comprehensive investigation into the microstructure of clay was conducted, involving X-ray phase analysis and SEM imaging analysis. The results revealed the following: (1) In comparison to the deep clay deposited in fluvial-lacustrine environments, the shallow mucky clay in marine sediments had a higher clay mineral content, accounting for 48%. Illite makes up the majority of it, with minor levels of kaolinite and montmorillonite being present. (2) The shallow mucky clay in the Hangzhou Estuarine Bay area had a typical agglomerate-flocculated structure. In contrast, the deeper clay showed a flocculated structure with less uniform particle sizes, strong stacking randomness, poor directional alignment of soil pores, and tends to form arrangements where edges are adjacent to faces or edges are adjacent to other edges. (3) Compared to the deep clay deposited in fluvial-lacustrine environments, the marine-deposited shallow mucky clay displayed orderly pore arrangements, strong directional alignment, significant pore shape variability, and minimal pore size changes between adjacent pores. The microstructure of soil plays a crucial role in determining the physical, mechanical, and other engineering properties of the soil. This study provides insightful information about the relationship between clay microstructure and geotechnical characteristics in Hangzhou and the surrounding areas.

Research on the Evolution and Driving Factors of the Economic Spatial Pattern of the Guangdong–Hong Kong–Macao Greater Bay Area in the Context of the COVID-19 Epidemic

Understanding the economic impact of COVID-19 is the foundation for formulating targeted policies promoting economic recovery. This study uses panel data of the county economy in the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) from 2017 to 2022. Firstly, the evolution characteristics of the economic structure in the GBA were analyzed using the standard deviation ellipse, geographical concentration, and spatial autocorrelation methods. Then, we revealed the changes in various economic indicators. Finally, a spatial Durbin model was constructed to study the factors affecting economic growth and spatial spillover effects in different periods. The results reveal that the economic distribution in the GBA presents a “core–edge” structure. The FDI, consumption, and exports of the Greater Bay Area fluctuate greatly, while investment growth is relatively stable. There is a significant spatial spillover effect in the county economy of the GBA. Investment, consumption, exports, labor, and innovation all have significant positive effects on economic growth, with investment having the greatest impact, while FDI has a significant negative impact. The impact of COVID-19 on the economy of the GBA is mainly reflected in the weakening of spatial spillovers, the strengthening of economic agglomeration, the decline in factor growth, and the change in the driving effect of factors on the economy. These findings can provide a reference for formulating targeted economic development policies.

High-Frequency Microbarograph-Observed Pressure Variations Associated with Gust Fronts during an Extreme Rainfall Event

This study aims to explore the roles of multiple gust fronts (i.e., outflow boundaries) during a short-lived extreme rainfall that occurred in the Greater Bay Area of South China in the afternoon of 1 August 2021. Through the use of microbarographs and Doppler weather radars, the research highlights how the interactions of five gust fronts, approaching the region from different directions, have contributed to the high precipitation efficiency and damaging surface winds during the event. The close convergence of these gust fronts funneled unstable air masses into the region of interest, priming the mesoscale convective environment. Some isolated convection initiated before the gust fronts’ arrival. Preceding the arrival of these gust fronts, subtle wave-like pressure jumps were identified from the high-frequency (1 Hz) microbarograph observations. The amplitude of the pressure jump is approximately 40 Pa with minimal changes in air temperature. During the early stage of the gust front passages, very high-frequency oscillations in surface pressure are recognized, indicating interaction between the density currents and the low-level troposphere. As suggested through numerical simulations, the subtle pressure jumps are associated with upward displacements of isentropic surfaces aloft, deepening the moist layer and enhancing the lapse rate that are conducive to convective development. The simulated vertical profiles show no evident capping inversion above the dry neutral boundary layer, suggesting that the pressure jumps are likely to be dynamically induced through the collision of the outflows and environmental air masses. The findings of this study suggest the potential application of microbarographs in the nowcasting of the convective development associated with gust fronts.

Examining the effect of salinity on dolphin mortality using Lagrangian particle tracking in a hydrodynamic model

Numerous dolphins are found dead on beaches and waterways of the Gulf of Mexico and Mississippi Sound every year. In 2019 an unusual mortality event (UME) occurred when 337 deceased bottlenose dolphins were stranded between Louisiana, Mississippi, Alabama, and Florida. According to NOAA, based on observations of skin lesions or distinct ulcerative dermatitis and other internal pathologic findings and the environmental conditions during that period of time, the identified cause of this UME was determined to be protracted exposure to low salinity waters. Dolphin carcasses are often found stranded on beaches days after they die. Consequently, their initial place of death is unknown. In this study, an existing 2D hydrodynamic model (EFDC+ 11.2) of the Mississippi Sound simulated by Armandei et al. (2021) was used to track dolphin carcass movement and to simulate salinity at the time and location of each predicted dolphin's death. Particles within the Lagrangian particle tracking module were used to represent the movement of 19 dolphin carcasses. A large number of particles (virtual dolphin carcasses) were seeded throughout the model domain and tracked for five days. These results were used to hindcast each dolphin's original location of death. The results indicate that the most likely place of death for 12 dolphins stranded on the beaches of Mississippi, along with the two found on Ship and Horn Islands, was west of their stranding location., For both of the dolphins stranded on Dauphin Island, the most likely place of death was in the Mobile Bay area north of where they were found. The remaining three dolphins found dead on barrier islands, most likely originally died in close proximity to their stranding locations. The average simulated salinity of all the dolphins' most probable original place of death was below five except for two cases. These results are compared to the salinity of the Mississippi Sound during Bonnet Carré spillway opening and non-opening dates. The results highlight the significant impact of the spillway's opening on the reduction of salinity and its association with dolphin mortality.

The Roles of Machine Translation in Learning Among K-12 Students at the International Schools in the Great Bay Area, China

Intercultural foreign language learning among K -12 students at international schools involves the cross-cultural discovery of the changing habits of people whose mother tongue might be different instructive languages at schools. Bilingual education is essential in bridging the gap between the mother tongue and instructive languages. However, it needs effective strategies that combine in-classroom language learning with new technology. Several language learning and teaching trends concerning the digital environment and innovative technologies such as machine translation or digitalization are currently challenging K-12 schools and families. This research investigates the role of machine translation in learning among K-12 students at international schools in the cities of Shenzhen, Guangzhou, and Zhuhai. It aims to identify these gaps in existing research and propose innovative strategies for boosting learning outcomes to recognize the learning habits they developed as young learners in the 21st century and their cultural motivations. Bilingual surveys are being handed out to K-12 families. These surveys are written in both English and Chinese. In total, 221 of them were collected. The data was analyzed to examine how helpful machine translation is for academic learning in both languages. The strengths and weaknesses were summarized among K-12 students using machine translation, highlighting strategies used with it at international K-12 schools.

Rationale, Procedures, and Response Rates for a Pilot Study to Sample Cancer Survivors for NCI’s Health Information National Trends Survey: HINTS-SEER 2021

The National Cancer Institute’s (NCI) Health Information National Trends Survey (HINTS) is a nationally representative survey of U.S. adults in which 12–17% of respondents report a cancer history. To increase representation from adult cancer survivors, in 2021, NCI sampled survivors from three Surveillance, Epidemiology, and End Results (SEER) program cancer registries: Iowa, New Mexico, and the Greater Bay Area. Sampling frames were stratified by time since diagnosis and race/ethnicity, with nonmalignant tumors and non-melanoma skin cancers excluded. Participants completed a self-administered postal questionnaire. The overall response rate for HINTS-SEER (N = 1,234) was 12.6%; a non-response bias analysis indicated few demographic differences between respondents and the pool of sampled patients in each registry. Most of the sample was 10+ years since diagnosis (n = 722; 60.2%); 392 respondents were 5 to < 10 years since diagnosis (29.6%); and 120 were < 5 years since diagnosis (10.2%). Common cancers included male reproductive (n = 304; 24.6%), female breast (n = 284; 23.0%), melanoma (n = 119; 9.6%), and gastrointestinal (n = 106; 8.6%). Tumors were mostly localized (67.8%; n = 833), with 22.4% (n = 282) regional, 6.2% (n = 72) distant, and 3.7% (n = 47) unknown. HINTS-SEER data are available by request and may be used for secondary analyses to examine a range of social, behavioral, and healthcare outcomes among cancer survivors.

Early Triassic S-Type Granitoids in the Qinzhou Bay Area, South China: Petrogenesis and Tectonic Implications

The influence of the paleo-Tethys or paleo-Pacific oceanic plate subduction on Early Triassic South China has long been debated. We have studied the zircon U-Th-Hf isotopes, trace elements, and whole-rock geochemistry of Early Triassic peraluminous granitoids in the Qinzhou Bay area, South China Block. LA–ICP–MS zircon U–Pb dating has revealed the Jiuzhou granodiorites and Dasi-Taima granite porphyries formed between 248.32 ± 0.98 and 246.6 ± 1.1 Ma. These rocks are characterized by high K2O and Al2O3, and low MgO, CaO, and P2O5 contents with A/CNK = 1.06–1.17, showing high-K calc-alkaline S-type affinities. The Early Triassic intrusive rocks and adjacent silicic volcanic rocks in the Qinzhou Bay area were found to be comagmatic and derived from a common magma pool, detached in an undifferentiated melt instead of indicating remarkable crystal—melt separation. Although the analyzed granitoids have highly enriched zircon Hf isotopic compositions (εHf(t) = −23.9 to −7.8), they cannot originate solely from metasedimentary protoliths. Source discrimination indicators have revealed enriched lithospheric mantle-derived magma was also an endmember component of the S-type silicic magma, which provided a heat source for the crustal anatectic melting as well. We inferred the studied Early Triassic granitoids formed under the paleo-Tethys tectonic regime before the collision of South China and Indochina blocks, as the oceanic plate subduction would have created an extensional setting which further caused the mantle-derived upwelling and volcanic eruption.

Exploring applications of non-targeted analysis in the characterization of the prenatal exposome

Capturing the breadth of chemical exposures in utero is critical in understanding their long-term health effects for mother and child. We explored methodological adaptations in a Non-Targeted Analysis (NTA) pipeline and evaluated the effects on chemical annotation and discovery for maternal and infant exposure. We focus on lesser-known/underreported chemicals in maternal and umbilical cord serum analyzed with liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF/MS). The samples were collected from a demographically diverse cohort of 296 maternal-cord pairs (n = 592) recruited in San Francisco Bay area. We developed and evaluated two data processing pipelines, primarily differing by detection frequency cut-off, to extract chemical features from non-targeted analysis (NTA). We annotated the detected chemical features by matching with EPA CompTox Chemicals Dashboard (n = 860,000 chemicals) and Human Metabolome Database (n = 3140 chemicals) and applied a Kendrick Mass Defect filter to detect homologous series. We collected fragmentation spectra (MS/MS) on a subset of serum samples and matched to an experimental MS/MS database within the MS-Dial website and other experimental MS/MS spectra collected from standards in our lab. We annotated ~72 % of the features (total features = 32,197, levels 1–4). We confirmed 22 compounds with analytical standards, tentatively identified 88 compounds with MS/MS spectra, and annotated 4862 exogenous chemicals with an in-house developed annotation algorithm. We detected 36 chemicals that appear to not have been previously reported in human blood and 9 chemicals that were reported in less than five studies. Our findings underline the importance of NTA in the discovery of lesser-known/unreported chemicals important to characterize human exposures.

Local exposure misclassification in national models: relationships with urban infrastructure and demographics

BackgroundNational-scale linear regression-based modeling may mischaracterize localized patterns, including hyperlocal peaks and neighborhood- to regional-scale gradients. For studies focused on within-city differences, this mischaracterization poses a risk of exposure misclassification, affecting epidemiological and environmental justice conclusions.ObjectiveCharacterize the difference between intraurban pollution patterns predicted by national-scale land use regression modeling and observation-based estimates within a localized domain and examine the relationship between that difference and urban infrastructure and demographics.MethodsWe compare highly resolved (0.01 km2) observations of NO2 mixing ratio and ultrafine particle (UFP) count obtained via mobile monitoring with national model predictions in thirteen neighborhoods in the San Francisco Bay Area. Grid cell-level divergence between modeled and observed concentrations is termed “localized difference.” We use a flexible machine learning modeling technique, Bayesian Additive Regression Trees, to investigate potentially nonlinear relationships between discrepancy between localized difference and known local emission sources as well as census block group racial/ethnic composition.ResultsWe find that observed local pollution extremes are not represented by land use regression predictions and that observed UFP count significantly exceeds regression predictions. Machine learning models show significant nonlinear relationships among localized differences between predictions and observations and the density of several types of pollution-related infrastructure (roadways, commercial and industrial operations). In addition, localized difference was greater in areas with higher population density and a lower share of white non-Hispanic residents, indicating that exposure misclassification by national models differs among subpopulations.ImpactComparing national-scale pollution predictions with hyperlocal observations in the San Francisco Bay Area, we find greater discrepancies near major roadways and food service locations and systematic underestimation of concentrations in neighborhoods with a lower share of non-Hispanic white residents. These findings carry implications for using national-scale models in intraurban epidemiological and environmental justice applications and establish the potential utility of supplementing large-scale estimates with publicly available urban infrastructure and pollution source information.

Surface Subsidence over a Coastal City Using SBAS-InSAR with Sentinel-1A Data: A Case of Nansha District, China

The loss of life and property in economically developed areas due to geological hazards caused by intense ground subsidence is incalculable. As one of the fastest growing areas in the Guangdong-Hong Kong-Macao Greater Bay Area, the study of ground subsidence in Nansha will help to provide a scientific basis for urban planning and improve the capacity of monitoring and prevention of ground subsidence. The combination of coastal soft soil foundation and urbanization conditions creates a certain risk of land subsidence. We chose Nansha District, the geographical center of the Greater Bay Area, as the study area to analyze its surface subsidence characteristics in recent years. The 20-view Sentinel-1A data and SBAS-InSAR technique were used to monitor the ground subsidence in Nansha from 2017 to 2023. The main rate of ground subsidence in Nansha ranges from −19.4 to 7.7 mm/yr and is distributed in the urban area, along the rivers, in the construction area, and in the reclamation area. As of 4 May 2023, the average ground settlement in Nansha is 10.05 mm and the maximum settlement can be up to 142.45 mm. The 6-year total settlement at all four settlement intensities is greater than 60 mm, with the highest value exceeding 110 mm. The cumulative settlement increases with time, but inverse settlement and no settlement also occur at points where settlement is severe. For settlement caused by soft soil consolidation, it is recommended that drainage pipes be installed to accelerate drainage as a means of stabilizing settlement. For settlement caused by groundwater extraction and additional loads on the road surface, it is recommended to rationally extract groundwater and reinforce the foundation of the road surface with severe settlement.