Inland Urban Areas Research Articles

Undesirable dispersal via a river pathway of a single Argentine ant supercolony newly invading an inland urban area of Japan

Invasive ants pose a risk to human well-being and social/ecosystem stability. Linepithema humile Mayr is among the most damaging invasive ants worldwide. Most L. humile populations invade ports/wharfs isolated from surrounding landscapes, but unfortunately, a new population was discovered in an inland urban area (Nara Prefecture) of Japan in 2021. In this study, first, the supercolony type of the Nara L. humile population was identified via a hostility test, and then its distribution pattern was characterized. In aggression tests between L. humile from Nara and four supercolonies (haplotypes LH1, LH2, LH3, LH4), this ant showed extremely strong hostility against all supercolonies exept LH2, which was detected only in Japan in its introduced range. In Nara, L. humile was abundant in and around the urban river. Simulations revealed that using this environment for movement/dispersal increased the annual dispersal ability by 14 times compared with that achieved via ground (125 m), as mentioned in the literature. Therefore, river channels can serve as major pathways of long-distance dispersal for L. humile invading inland urban areas. Since applying chemical strategies around rivers is problematic, preventing L. humile from moving to rivers from initial invasion sites is crucial.

The effects of coastal local circulations and their interactions on ozone pollution in the Hangzhou metropolitan area

Impacts of coastal local circulations and their interactions on ozone (O3) in Hangzhou on 5 June 2018 with relatively low temperatures were investigated using surface observations and three-dimensional air quality simulations. Local circulations and their interactions were primary causes of the episode instead of high temperatures. Northwesterly land breeze on the previous day transported O3 to sea, and sea breeze (SB) on the episode day blew pollution back to land. Inland penetration (east to west) of the combined SB front (SBF) was accelerated by urban heat island (UHI) induced easterly flow over coast and slowed by its westerly flow and surface roughness over inland urban areas. O3 accumulation at surface and in the elevated air over city was caused by mountain barrier effect and venting process. Subsidence heating associated with valley circulation accelerated UHI circulation (UHIC) before 1400 LT, indirectly strengthening the SB circulation (SBC). The UHIC and valley circulation decoupled with SBC at noon and in the late afternoon, respectively, leading to a stronger SBC. The stronger SBC brought additional O3 (>20 ppb) to further inland area, to elevated air with updrafts in SB head, and to nocturnal stable boundary layer and residual layer with its upper-level offshore flow.

Analysis of Dollarization Hysteresis among North Korean Consumers

This paper quantitatively analyzes the current status of North Korean consumer payment instruments through a questionnaire survey of 292 North Korean defectors. In the 2010s, it was found that the payment experience ratio of domestic currency cash and grain decreased, while the payment experience ratio of foreign currency cash increased. The use of foreign currency reached a stage where it was spread not only as a store of value but also as a medium of exchange. However, the most frequently used payment instrument by North Korean consumers was still domestic currency cash. By region, in inland urban areas both domestic currency cash and U.S. dollars are used and in the North Korea-China border region both domestic currency cash and Chinese yuan are used, while in inland rural areas dollarization does not occur because both domestic currency cash and grain are used. Meanwhile, despite the stable price trend during 2013-2019, the dollarization hysteresis effect is appearing, and both the purchasing power risk theory and the network externality theory are considered to have explanatory power for the cause. The results of this paper suggest that as dollarization is intensifying, it is expected that more costs such as shortages of commodities will be incurred than in the past if North Korea’s de-dollarization policy is reimplemented. Also, in the case of domestic currency cards, which the North Korean authorities introduced in 2015 as part of a means of financial reform, this paper suggests that it may continue to be difficult for domestic currency cards to normalize official finance under the dollarization hysteresis.

Evaluation of LaSRC aerosol optical depth from Landsat-8 and Sentinel-2 in Guangdong-Hong Kong-Macao greater bay area, China

The aerosol optical depth (AOD) is a key factor to assess atmospheric environment, and accurate monitoring of it is conducive to the research and environmental protection. The Land Surface Reflectance Code (LaSRC) algorithm has been used to retrieve AOD from fine resolution satellite instruments, including the Landsat-8 and Sentinel-2. This study evaluated the AODs against the in situ data (i.e., Aerosol Robotic Network and Sun-Sky Radiometer Observation NETwork measurements). The temporal window and wind speed were jointly applied to determine the spatial window size (i.e., 6 km) centered on the in situ site. And a three-step strategy for calculating the average of satellite retrieved AODs within the spatial window was proposed in this study. As a result, both STEPs 2 and 3 had improvements compared to STEP 1 and the three-step strategy achieved the best performance in terms of the highest coefficient of determination (R2: 0.754) and within expected error (EE: 60.81%), the lowest root mean square error (RMSE: 0.150) and mean absolute error (MAE: 0.113). Then the contemporaneous AOD matchups were used for validation and evaluation of the LaSRC retrieved AODs. The Sentinel-2 AOD retrievals outperformed the Landsat-8 AOD retrievals with lower RMSE (0.138 and 0.173, respectively), lower MAE (0.102 and 0.136, respectively), higher R2 (0.818 and 0.707, respectively) and higher within EE (64.36% and 53.19%, respectively). However, there are 31.91% of Landsat-8 matchups falling below EE and 32.67% of Sentinel-2 collocations falling above EE, which were mainly detected at HKP and HKS sites. And the site-scale validation results revealed that the LaSRC algorithm performed well over inland urban areas, but should be developed further over coastal and water areas in the next generation.

ASI: An artificial surface Index for Landsat 8 imagery

Remotely sensing the spatial extent of artificial surfaces is essential for understanding human footprints and evaluating anthropogenic impacts on the global environment and climate. However, since the spectral signatures of artificial surfaces are similar to other bright natural surfaces, it is still a difficult task to separate artificial surfaces from other natural surfaces. Therefore, this study proposed a new Artificial Surface Index (ASI) to extract artificial surfaces based on the multispectral Landsat 8 imagery. We examined the performance of ASI in eight study areas with a variety of landscapes, including desert, coastal, inland urban and rural areas dominated by different climates and land cover categories. We also compared ASI with seven state-of-the-art built-up area or impervious surface indices that are developed for similar purposes. The qualitative and quantitative evaluations demonstrate that ASI has advantages in suppressing non-artificial surfaces with similar spectral signatures to artificial surfaces, such as deserts, bare soil, and harvested croplands. Furthermore, ASI improves the separability between artificial and non-artificial surfaces by 2% to 75% (measured by Jeffries–Matusita Distance), 13% to 164% (measured by Transformed Divergence), and 3% to 131% (measured by Spectral Discrimination Index) compared to the other seven indices across the eight study areas. The newly proposed ASI index has the potential to support a variety of human-activity-related studies, such as change detection of artificial surfaces, urban planning, land resource management at local, continental, and even global scales.

Predicting the potential distribution of a previously undetected cryptic invasive synanthropic Asian house rat (Rattus tanezumi) in South Africa

Abstract Three species of Rattus, Norway rat (R. norvergicus), black rat (R. rattus) and Asian house rat (R. tanezumi) are currently known to occur in South Africa. The latter two species are cryptic and form part of the Rattus rattus species complex. Historically, R. norvegicus has been reported to occur along the coast and in urban centres, R. rattus is widespread in most urban areas, except in the drier areas, while R. tanezumi was only recorded to occur in the country (and Africa) ca. 15 years ago, and its distribution remains unknown. The aim of this study was to predict the potential distribution of R. tanezumi in South Africa and assess how it overlaps with that of R. norvegicus and R. rattus using species distribution modelling. Rattus tanezumi was predicted to mainly occur in most inland urban areas and along the coast. The distribution of R. rattus was as expected, in contrast, the predicted range of R. norvegicus was not restricted to the coast but also included inland urban areas. All three species showed broad potential distributional ranges that overlapped extensively indicating that their establishment and spread may be influenced by similar factors such as proximity to urban areas and a wet and moderate climate. These results allow insights into assessing their risk of establishment and for formulating appropriate intervention strategies for their management and control.

Atmospheric gaseous hydrochloric and hydrobromic acid in urban Beijing, China: detection, source identification and potential atmospheric impacts

Abstract. Gaseous hydrochloric (HCl) and hydrobromic acid (HBr) are vital halogen species that play essential roles in tropospheric physicochemical processes. Yet, the majority of the current studies on these halogen species were conducted in marine or coastal areas. Detection and source identification of HCl and HBr in inland urban areas remain scarce, thus limiting the full understanding of halogen chemistry and potential atmospheric impacts in the environments with limited influence from the marine sources. Here, both gaseous HCl and HBr were concurrently measured in urban Beijing, China, during winter and early spring of 2019. We observed significant HCl and HBr concentrations ranging from a minimum value at 1 × 108 molecules cm−3 (4 ppt) and 4 × 107 molecules cm−3 (1 ppt) up to 6 × 109 molecules cm−3 (222 ppt) and 1 × 109 molecules cm−3 (37 ppt), respectively. The HCl and HBr concentrations are enhanced along with the increase of atmospheric temperature, UVB and levels of gaseous HNO3. Based on the air mass analysis and high correlations of HCl and HBr with the burning indicators (HCN and HCNO), gaseous HCl and HBr are found to be related to anthropogenic burning aerosols. The gas–particle partitioning may also play a dominant role in the elevated daytime HCl and HBr. During the daytime, the reactions of HCl and HBr with OH radicals lead to significant production of atomic Cl and Br, up to 2 × 104 molecules cm−3 s−1 and 8 × 104 molecules cm−3 s−1, respectively. The production rate of atomic Br (via HBr + OH) is 2–3 times higher than that of atomic Cl (via HCl + OH), highlighting the potential importance of bromine chemistry in the urban area. On polluted days, the production rates of atomic Cl and Br are faster than those on clean days. Furthermore, our observations of elevated HCl and HBr may suggest an important recycling pathway of halogen species in inland megacities and may provide a plausible explanation for the widespread halogen chemistry, which could affect the atmospheric oxidation in China.

Planetary Boundary-Layer Structure at an Inland Urban Site under Sea Breeze Penetration

We evaluated the performance of the Weather Research and Forecasting Model in simulating the boundary-layer structure at an urban site in Seoul on two clear summer days against observations made using a ceilometer, a Doppler wind lidar, and a microwave radiometer. The planetary boundary-layer height (PBLH) was estimated from two different methods using observations: the ceilometer-based method (CBM) and bulk Richardson number method (BRM). The maximum PBLH was well captured by the model but PBLH was underestimated in the late afternoon and evening. To examine the cause for underestimation of PBLH in the evening, we compared the wind and virtual potential temperature structure between the simulation and observations. The model captured the timing of the sea breeze well, but it considerably overestimated the intensity of the simulated sea breeze, resulting in an overestimated cold advection by a sea breeze. The effect of the overestimated cold advection on evening PBLH was greater when the sea breeze arrived in the late afternoon and hence the vertical extent of the sea breeze was shallow. This study underscores the importance of accurately simulating the sea breeze for PBLH prediction in the evening, over the inland urban areas under sea breeze penetration.

基于生态系统服务供需匹配与耦合协调的生态管理分区——以大连市为例

生态管理分区是建设用地扩张指引和生态空间管控的重要依据，对维护区域生态安全和生态文明建设具有重要意义。以我国北方沿海重要中心城市——大连市为例，选取食物供给、水源涵养、固碳释氧、土壤保持、生境维持和美学景观6项指标，综合运用模型法及生态经济学方法量化生态系统服务供给，并结合土地利用、人口和经济现状定量评估2015年生态系统服务需求。利用象限匹配法和耦合协调度模型，探究千米网格尺度下生态系统服务供需匹配关系和协调关系及其区域差异，进而通过空间叠置分析划分生态管理分区并提出相应管理措施，旨在为区域内生态修复以及差异化建设提供科学参考。研究结果表明：①大连市生态系统服务供需具有显著空间异质性，总体呈现北部林地和东西部沿海生态系统服务供给高、需求低，中南内陆城镇区生态系统服务供给低、需求高的空间格局；②生态系统服务供需不匹配和失调特征明显，匹配类型以高供给-低需求和低供给-高需求为主，生态系统服务供需耦合协调度平均值为0.38，表现为轻度失调；③综合分析将大连分为4个生态管理区，其中，生态涵养区为高供低需-供需失调区，要以保护为主培育为辅，重点保护；生态农业区为高需-供需平衡区，以生态保护和生态建设为主，提高其投入产出效率；生态改良为低供高需-供需失调区，以生态建设和整治为主，综合改善生态系统服务水平；生态一般保护区为高供-供需失调区，以综合保护为主，提高生态溢出效应。;Ecological management zoning is an important basis for construction land expansion guidelines and ecological space management,and is of great significance to maintain regional ecological security and ecological civilization construction. Taking Dalian,a coastal city in northern China,as an example,six indicators including food supply,water retention,carbon sequestration and oxygen release,soil conservation,habitat support,and aesthetic landscape are selected,and ecological economics methods are used to quantify the supply of ecosystem services (ES). We combined land use,population,and economic status to quantitatively assess the ES demand in 2015. Using the quadrant matching method and the coupling coordination degree model,we explore the matching relationship and coordination relationship of ES supply-demand and its regional differences at the 1 km grid scale. Then we divide the ecological management zone via spatial overlay analysis and propose management measures. It can provide scientific references for ecological restoration and differentiated construction in the region. The results show that: ① the supply and demand of ES in Dalian has significantly spatial heterogeneity,and overall there is a space with high supply and low demand for ES in northern forests and east and west coastal area,and low ES supply and high demand in central and southern inland urban areas. ② The ES supply-demand mismatch and imbalance characteristics are obvious. The matching types are mainly high supply-low demand and low supply-high demand. The average value of the coupling coordination degree of ES supply and demand is 0.38,which is a mild imbalance. ③ The comprehensive analysis divides Dalian into 4 ecological management zones. Among them,the ecological conservation zone is the high supply and low demand-supply and demand imbalance area,which should be protected as the main cultivation supplemented by the key protection; the ecological agriculture zone is high demand-supply and demand balance area,focusing on environmental protection and ecological construction,to improve its input and output efficiency; ecological improvement zone is a low supply and high demand-supply and demand imbalance area,focusing on ecological construction and renovation,and comprehensively improving the ES level; general ecological protection zone is a high supply-supply and demand imbalance area,which focuses on comprehensive protection to improve the ecological spillover effect.

GIS-Based Optimum Geospatial Characterization for Seismic Site Effect Assessment in an Inland Urban Area, South Korea

Soil and rock characteristics are primarily affected by geological, geotechnical, and terrain variation with spatial uncertainty. Earthquake-induced hazards are also strongly influenced by site-specific seismic site effects associated with subsurface strata and soil stiffness. For reliable mapping of soil and seismic zonation, qualification and normalization of spatial uncertainties is required; this can be achieved by interactive refinement of a geospatial database with remote sensing-based and geotechnical information. In this study, geotechnical spatial information and zonation were developed while verifying database integrity, spatial clustering, optimization of geospatial interpolation, and mapping site response characteristics. This framework was applied to Daejeon, South Korea, to consider spatially biased terrain, geological, and geotechnical properties in an inland urban area. For developing the spatially best-matched geometry with remote sensing data at high spatial resolution, the hybrid model blended with two outlier detection methods was proposed and applied for geotechnical datasets. A multiscale grid subdivided by hot spot-based clusters was generated using the optimized geospatial interpolation model. A principal component analysis-based unified zonation map identified vulnerable districts in the central old downtown area based on the integration of the optimized geoprocessing framework. Performance of the geospatial mapping and seismic zonation was discussed with digital elevation model, geological map.

Rising Trends in Heatwave Metrics Across Southern California

AbstractResearch on heatwaves has gained significant impetus over the past decade due to a warming planet and rapid 21st century urbanization. This study examines driving factors influencing heatwave trends and interannual variability across Southern California (SoCal) from 1950–2020. Inland urban areas of Los Angeles county are the most susceptible to heatwaves with strong increasing trends in frequency, duration, and intensity that are closely tied to nighttime warming. Coastal and rural areas are less impacted but show a significant increase in heatwave frequency over the past two decades. Heatwave nighttime temperatures combined with high humidity have been increasing at a rapid rate of ~1°C/decade since the 1980s—elevating heat stress and mortality risk to vulnerable urban communities. The increased nighttime humidity is associated with an anomalous moisture source off the coast of Baja California that has intensified over the past decade and is linked to ocean warming trends and changes in the California current system. Heatwaves are starting earlier and ending later in the year for urban regions. This augments public health risks and sets the stage for more intense fall wildfires by enhancing the drying of fuels. Droughts and heatwaves are strongly linked, particularly in inland urban and rural areas that have a high statistical probability of heatwaves increasing in frequency (42%), duration (26%), and daily mean temperature (2.2%) during severe drought conditions. Better understanding of heatwave climate drivers and underlying physical processes could help with prediction skill, in addition to providing effective data‐driven recommendations for mitigation efforts in SoCal's vulnerable urban regions.

Observation of Road Salt Aerosol Driving Inland Wintertime Atmospheric Chlorine Chemistry.

Inland sources of particulate chloride for atmospheric nitryl chloride (ClNO2) formation remain unknown and unquantified, hindering air quality assessments. Globally each winter, tens of millions of tons of road salt are spread on roadways for deicing. Here, we identify road salt aerosol as the primary chloride aerosol source, accounting for 80–100% of ClNO2 formation, at an inland urban area in the wintertime. This study provides experimental evidence of the connection between road salt and air quality through the production of this important reservoir for nitrogen oxides and chlorine radicals, which significantly impact atmospheric composition and pollutant fates. A numerical model was employed to quantify the contributions of chloride sources to ClNO2 production. The traditional method for simulating ClNO2 considers chloride to be homogeneously distributed across the atmospheric particle population; yet, we show that only a fraction of the particulate surface area contains chloride. Our new single-particle parametrization considers this heterogeneity, dramatically lowering overestimations of ClNO2 levels that have been routinely reported using the prevailing methods. The identification of road salt as a ClNO2 source links this common deicing practice to atmospheric composition and air quality in the urban wintertime environment.

Relationship between City Size, Coastal Land Use, and Summer Daytime Air Temperature Rise with Distance from Coast

The relationship between city size, coastal land use, and air temperature rise with distance from coast during summer day is analyzed using the meso-scale weather research and forecasting (WRF) model in five coastal cities in Japan with different sizes and coastal land use (Tokyo, Osaka, Nagoya, Hiroshima, and Sendai) and inland cities in Germany (Berlin, Essen, and Karlsruhe). Air temperature increased as distance from the coast increased, reached its maximum, and then decreased slightly. In Nagoya and Sendai, the amount of urban land use in coastal areas is less than the other three cities, where air temperature is a little lower. As a result, air temperature difference between coastal and inland urban area is small and the curve of air temperature rise is smaller than those in Tokyo and Osaka. In Sendai, air temperature in the inland urban area is the same as in the other cities, but air temperature in the coastal urban area is a little lower than the other cities, due to an approximate one degree lower sea surface temperature being influenced by the latitude. In three German cities, the urban boundary layer may not develop sufficiently because the fetch distance is not enough.

Global assessment of rural–urban interface in Portugal related to land cover changes

Abstract. The rural–urban interface (RUI), known as the area where structures and other human developments meet or intermingle with wildland and rural area, is at present a central focus of wildfire policy and its mapping is crucial for wildfire management. In the Mediterranean Basin, humans cause the vast majority of fires and fire risk is particularly high in the proximity of infrastructure and of rural/wildland areas. RUI's extension changes under the pressure of environmental and anthropogenic factors, such as urban growth, fragmentation of rural areas, deforestation and, more in general, land use/land cover change (LULCC). As with other Mediterranean countries, Portugal has experienced significant LULCC in the last decades in response to migration, rural abandonment, ageing of population and trends associated with the high socioeconomic development. In the present study, we analyzed the LULCC occurring in this country in the 1990–2012 period with the main objective of investigating how these changes affected RUI's evolution. Moreover, we performed a qualitative and quantitative characterization of burnt areas within the RUI in relation to the observed changes. Obtained results disclose important LULCC and reveal their spatial distribution, which is far from uniform within the territory. A significant increase in artificial surfaces was registered near the main metropolitan communities of the northwest, littoral-central and southern regions, whilst the abandonment of agricultural land near the inland urban areas led to an increase in uncultivated semi-natural and forest areas. Within agricultural areas, heterogeneous patches suffered the greatest changes and were the main contributors to the increase in urban areas; moreover, this land cover class, together with forests, was highly affected by wildfires in terms of burnt area. Finally, from this analysis and during the investigated period, it appears that RUI increased in Portugal by more than two-thirds, while the total burnt area decreased by one-third; nevertheless, burnt area within RUI doubled, which emphasizes the significance of RUI monitoring for land and fire managers.

Abundance and origin of fine particulate chloride in continental China

Particulate chloride can be converted to nitryl chloride (ClNO2) through heterogeneous reactions with dinitrogen pentoxide (N2O5), and photolysis of ClNO2 affects atmospheric oxidative capacity. However, the characteristics and sources of chloride, especially those with an anthropogenic origin, are poorly characterized, which makes it difficult to evaluate the effects of ClNO2 on radical chemistry and air quality in polluted regions. Aerosol composition data from the literature were compiled to derive the spatial distributions of particulate chloride across China, and hourly aerosol composition data collected at a highly polluted inland urban site in eastern China and at a coastal site in southern China were analysed to gain further insights into non-oceanic sources of chloride. The results show that particulate chloride is concentrated mainly in fine particles and that high chloride loadings are observed in the inland urban areas of northern and western China with higher Cl−/Na+ mass ratios (2.46 to 5.00) than sea water (1.81), indicative of significant contributions from anthropogenic sources. At the inland urban site, the fine chloride displays distinct seasonality, with higher levels in winter and summer. Correlation analysis and positive matrix factorization (PMF) results indicate that coal combustion and residential biomass burning are the main sources (84.8%) of fine chloride in winter, and open biomass burning is the major sources (52.7%) in summer. The transport of plumes from inland polluted areas leads to elevated fine chloride in coastal areas. A simulation with WRF-Chem model confirmed a minor contribution of sea-salt aerosol to fine chloride at the inland site during summer with winds from the East Sea. The widespread sources of chloride, together with abundant NOx and ozone, suggest significant ClNO2 production and subsequent enhanced photochemical processes over China.

GIS-based regional assessment of seismic site effects considering the spatial uncertainty of site-specific geotechnical characteristics in coastal and inland urban areas

ABSTRACTEarthquake-induced hazards are profoundly affected by site effects related to the amplification of ground motions, which are strongly influenced by site-specific geologic conditions such as soil thickness, bedrock depth and soil stiffness. Seismic disasters are often more severe in coastal or riverside locations than over stiff soils or rocks due to differences in local site effects. In this study, a recently developed geographic information system-based framework was applied in coastal and inland urban areas in Korea, and its applicability for regional assessments was evaluated using appropriate geostatistical zonation of site-specific seismic site effects. The proposed framework was composed of four functional components: multivariable statistical clustering, geostatistical optimization, geotechnical analysis, and local visualization. The framework was applied in the Seoul and Busan areas of Korea for consideration of site effects in inland and coastal urban areas. Such zones of thick soil, or with a deep depth to bedrock, are susceptible to ground motion amplification due to site effects during earthquakes. The earthquake losses associated with possible building damage can be estimated based on spatial zoning maps considering geological and topographical characteristics and by a comparison of the spatial correlations of seismic site classes between inland and coastal areas of Korea.

The changing influence of city-systems on global shipping networks: an empirical analysis

This paper revisits the classical issue of port-city relationships by applying for the first time network analytical methods to maritime flows connecting cities of the world, over the period 1950–1990. A global matrix of interurban vessel flows was elaborated for about 600 cities using data from the Geopolis and Lloyd’s Shipping Index databases and the rigorous assignment of ports to both coastal and inland urban areas. Main results show that although the largest cities have witnessed a diminishing importance in world traffic, they have maintained their dominance in the network in terms of centrality and geographic reach. This research thus contributes to question the ineluctable separation between ports and cities which dominated the literature, while offering new empirical evidence about the structure and dynamics of city-systems and spatial networks in general.

Resilience of Inland Urban Areas to Disasters Occurred Due to Extreme Precipitations

Among possible manifestations of climate change, which, according to predictions for coming period, may oc- cur in different regions of Europe, are the extreme precipitations. These events, often accompanied by storms, may further lead to a whole series of consequences in urban environment and to the occurrence of disasters, such as massive floods. Starting from the description of case of Serbia floods 2014, this paper identifies some of the past human mistakes with ex- perienced (and possibly future) catastrophic consequences, gives overview of future climate change expectations in terms of extreme precipitation occurrence, considers possible negative implications on urban population, built environment and functions, and defines resilient city concept. Finally, the paper introduces strategic proposal on achieving flood-resilient cities. Proposed concept deals both with the mitigation of past errors and the introduction of new, climate-resilient prac- tice in further urban development. Time gap between future (with supposed achieved resilience) and present moment (with supposed high level of vulnerability and therefore risks) is overcome by definition of priorities and introduction of three different time-related categories of actions and results: immediate, short-term and long-term. Achieving social pre- paredness for possible extreme weather events represents the first important step in reducing the possibility of their nega- tive transformation into disaster.

Assessing the need for evacuation assistance in the 100 year floodplain of South Florida

The main objective of this study is to assess evacuation assistance need in the 100 year floodplain of South Florida (Palm Beach, Broward and Miami-Dade counties) by examining select population characteristics of the floodplain inhabitants. Dasymetric mapping is used to redistribute block group level census data to homogeneous inhabited zones of 30 m × 30 m. Because the 100 year floodplain does not correspond to block group boundaries, this data redistribution increases the resolution and accuracy of the floodplain population and their social characteristics. Data on poverty, age, vehicle ownership and mobile housing units are obtained for each 30 m × 30 m zone in the floodplain and is aggregated to the block group level. It is then used to assess evacuation assistance need (based on volume of need as well as concentration of need) for the floodplain in each block group. Results reveal variations in evacuation need across the floodplain. “Age” is the main driver of evacuation need along the coast. “Poverty” is a factor inland, in both urban and rural areas. “Lack of vehicle ownership” contributes to assistance need in coastal and inland urban areas, but not so much in rural areas. “Mobile housing” is a factor in rural areas. Miami-Dade County has higher volume and concentration of poor households lacking vehicular ownership. Palm Beach and Broward counties, on the other hand, have a more dominant presence of elderly and of mobile housing. These results have important implications for local and regional evacuation planning in the event of a 100 year flood.

Dissolved total hydrolyzable enantiomeric amino acids in precipitation: Implications on bacterial contributions to atmospheric organic matter

We analyzed dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and dissolved enantiomeric amino acids in precipitation samples collected at two sites in Korea over a one-year period. The average concentrations of DOC, DON, and total hydrolyzable amino acids at Seoul (an inland urban area) were lower than those at Uljin (a coastal rural area). The different bulk compositions of dissolved organic matter (DOM) at these two sites (reflected by qualitative indicators) were mainly attributed to differences in contributing sources. The d-enantiomers of four individual amino acids (aspartic acid, glutamic acid, serine, and alanine) were ubiquitously present, with average enantiomeric (d/l) ratios of 0.34, 0.26, 0.21, and 0.61 for Seoul, and 0.18, 0.11, 0.09, and 0.31 for Uljin, respectively. The much higher d/l ratios observed at Seoul than at Uljin might result from more advanced diagenetic stages as well as higher contributions from bacteria inhabiting terrestrial environments. The C- and N-normalized yields of d-alanine in DOM of our samples were found to be comparable to literature values reported for aquatic systems, where a significant portion of DOM was suggested to be of bacterial origin. Our study suggests that bacteria and their remnants might constitute an important fraction of OM in the atmosphere, contributing significantly to the quality of atmospheric OM and its post-depositional bioavailability in the surface ecosystems.