The persistence of ancient settlements and urban sustainability.

We propose a dedicated research effort on the determinants of settlement persistence in the ancient world, with the potential to significantly advance the scientific understanding of urban sustainability today. Settlements (cities, towns, villages) are locations with two key attributes: They frame human interactions and activities in space, and they are where people dwell or live. Sustainability, in this case, focuses on the capacity of structures and functions of a settlement system (geography, demography, institutions) to provide for continuity of safe habitation. The 7,000-y-old experience of urbanism, as revealed by archaeology and history, includes many instances of settlements and settlement systems enduring, adapting to, or generating environmental, institutional, and technological changes. The field of urban sustainability lacks a firm scientific foundation for understanding the long durée, relying instead on narratives of collapse informed by limited case studies. We argue for the development of a new interdisciplinary research effort to establish scientific understanding of settlement and settlement system persistence. Such an effort would build upon the many fields that study human settlements to develop new theories and databases from the extensive documentation of ancient and premodern urban systems. A scientific foundation will generate novel insights to advance the field of urban sustainability.

Impacts of Gentrification on Health in the US: a Systematic Review of the Literature.

Gentrification in the largest 50 US cities has more than doubled since the 1990s. The process of gentrification can bring about improved neighborhood conditions, reduced rates of crime, and property value increases. At the same time, it can equally foster negative conditions associated with poorer health outcomes, such as disrupted social networks from residential displacement and increases in stress. While neighborhood environment is consistently implicated in health outcomes research, gentrification is rarely conceptualized as a public health issue. Though research on gentrification is growing, empirical studies evaluating the health impacts of gentrification in the US are poorly understood. Here we systematically review US population-based empirical studies examining relationships between gentrification and health. Electronic databases (PubMed, Embase, CINAHL, PsycINFO, Scopus, Web of Science, and Academic Search Complete) were searched using a combination of terms to identify peer-reviewed studies published on or before July 9, 2018, reporting associations between gentrification and health. Study title and abstract screenings were followed by full-text review of all studies meeting the following inclusion criteria of: ≥ 1 quantitative measure of association for a health outcome, within the context of gentrification; peer-reviewed research; located in the US; and English language. Of 8937 studies identified, 6152 underwent title and abstract screening, and 50 studies underwent full-text screening, yielding six studies for review. Gentrification exposure measures and health outcomes examined varied widely. Most studies reported little to no overall association between gentrification and health outcomes; however, gentrification was repeatedly associated with undesirable health effects among Black and economically vulnerable residents. Despite seemingly overall null associations between gentrification and health, evidence suggests that gentrification may negatively impact the health of certain populations, particularly Black and low-income individuals. Complexities inherent in operationalizing gentrification point toward the need for validated measures. Additionally, understanding how gentrification-health associations differ across health endpoints, race/ethnicities, socioeconomic status, and life course can provide insight into whether this process contributes to urban inequality and health disparities. As gentrification occurs across the US, it is important to understand how this process impacts health. While aging cities reinvest in the revitalization of communities, empirical research examining relationships between gentrification and health can help inform policy decisions.

Gentrification, Neighborhood Change, and Population Health: a Systematic Review.

Despite a proliferation of research on neighborhood effects on health, how neighborhood economic development, in the form of gentrification, affects health and well-being in the USA is poorly understood, and no systematic assessment of the potential health impacts has been conducted. Further, we know little about whether health impacts differ for residents of neighborhoods undergoing gentrification versus urban development, or other forms of neighborhood socioeconomic ascent. We followed current guidelines for systematic reviews and present data on the study characteristics of the 22 empirical articles that met our inclusion criteria and were published on associations between gentrification, and similar but differently termed processes (e.g., urban regeneration, urban development, neighborhood upgrading), and health published between 2000 and 2018. Our results show that impacts on health vary by outcome assessed, exposure measurement, the larger context-specific determinants of neighborhood change, and analysis decisions including which reference and treatment groups to examine. Studies of the health impacts of gentrification, urban development, and urban regeneration describe similar processes, and synthesis and comparison of their results helps bridge differing theoretical approaches to this emerging research. Our article helps to inform the debate on the impacts of gentrification and urban development for health and suggests that these neighborhood change processes likely have both detrimental and beneficial effects on health. Given the influence of place on health and the trend of increasing gentrification and urban development in many American cities, we discuss how future research can approach understanding and researching the impacts of these processes for population health.

Reconciling opposing perceptions of access to physical activity in a gentrifying urban neighborhood.

OBJECTIVE: We sought to understand perspectives on access to physical activity in a gentrifying neighborhood. DESIGN: This qualitative descriptive study used street intercept interviews and photo documentation. SAMPLE: Participants included members (n = 19) of a gentrifying neighborhood in a northeastern city. RESULTS: Participants held markedly different perceptions of opportunities for physical activity. Some participants, particularly area university students or those who are identified as White, perceived the neighborhood as favorable to physical activity, with high walkability and abundant resources. Other participants, particularly those who identified as Black or African-American, felt it was difficult to be physically active because neighborhood recreation facilities are scarce or unaffordable and parks are poorly maintained or unsafe. Multiple participants noted strategies to overcome neighborhood barriers to physical activity. Regardless of neighborhood perceptions, family and friends played an important role in influencing physical activity. CONCLUSIONS: Nurses must consider how disparities in actual and perceived access to neighborhood resources influence participation in physical activity, particularly in gentrifying neighborhood. Public health nurses are embedded in the neighborhoods that they serve, providing a unique opportunity to understand and address the impact of neighborhood on health.

Spatial characteristics and risk factor identification for land use spatial conflicts in a rapid urbanization region in China.

Land use conflict is a complex problem driven by a myriad of risk factors as a result of rapid socioeconomic development and urbanization. Analyzing the spatial characteristics of land use conflict and identifying its risk factors using statistical models will help us to better understand the causes and effects of the land use conflicts for sustainable management of the limited land resources under the pressure of rapid urbanization. In this study, regression models including multiple linear regression (MLR), spatial autoregressive (SAR), and geographically weighted regression (GWR) models were employed to identify risk factors for the land use spatial conflicts in the Urban Agglomeration around Hangzhou Bay (UAHB) of China in the past 25 years. Our results showed that the overall extent and the higher-level land use spatial conflicts were actually on the decline, and their spatial autocorrelation has been weakening in the UAHB. The key risk factors that mainly caused the land use spatial conflicts in the UHAB appeared to be different at the global and local scales. This knowledge should help urban managers and policymakers to be better informed when developing pertinent land use policies at the regional and local levels. This study also underlined the importance of considering spatial autocorrelation and scale effects when identifying the risk factors for land use spatial conflicts. The lessons learned from this particular context can be extended to other areas under rapid urbanization to assess and better manage their land resources for sustainable use. Graphical abstract.

Stream flow composition and sediment yield comparison between partially urbanized and undisturbed coastal watersheds-case study: St. John, US Virgin Islands.

In steep dry-tropical islands, rural and urban development can lead to accelerated soil erosion and the delivery of land-based materials into marine ecosystems. The objective of this paper was to compare stream water composition, clay minerology, and sediment yield between a partially urbanized (Coral Bay) and an undisturbed (Lameshur) coastal watersheds in St. John, US Virgin Islands (USVI). The saturation index of streamflow water samples was calculated using "The Geochemist's Workbench" software and most likely precipitated minerals from observed storm events was then compared with X-ray diffraction on soil clay mineralogy. The spatial distribution on both annual mean (2010) erosion rates and storm event-wise (Hurricane Otto) sediment yield among the two study watersheds were modeled using the revised and modified universal soil loss equations (RUSLE; MUSLE), respectively. Cations concentration in stream flow water samples and sediment yield were higher for the partially urbanized (Coral Bay) compared to the undisturbed (Lameshur) watershed. Our findings suggest that rural/urban development may increase stream water cations concentration and inputs of sediment to downstream ecosystems. Future studies evaluating the effect of management practices such as pavement or other stabilization of dirt roads and their impact on stream water quality and quantity and sediment yield are crucial for the proper sediment management in the study watersheds and potentially in other rural-urbanizing tropical watersheds.

Urban Renewal Mega Projects and Residents' Quality of Life: Evidence from Historical Religious Center of Mashhad Metropolis.

Urban decay is the process by which a historical city center, or an old part of a city, falls into decrepitude and faces serious problems. Urban management, therefore, implements renewal mega projects with the goal of physical and functional revitalization, retrieval of socioeconomic capacities, and improving of quality of life of residents. Ignoring the complexities of these large-scale interventions in the old and historical urban fabrics may lead to undesirable consequences, including an additional decline of quality of life. Thus, the present paper aims to assess the impact of renewal mega projects on residents' subjective quality of life, in the historical religious district of the holy city of Mashhad (Samen District). A combination of quantitative and qualitative methods of impact assessment, including questionnaires, semi-structured personal interviews, and direct observation, is used in this paper. The results yield that the Samen Renewal Project has significantly reduced the resident's subjective quality of life, due to its undesirable impacts on physical, socio-cultural, and economic environments.

Evaluating the impact of improvements in urban green space on older adults' physical activity and wellbeing: protocol for a natural experimental study.

BACKGROUND: Creating or improving urban green space has the potential to be an effective, sustainable and far-reaching way to increase physical activity and improve other aspects of wellbeing in the population. However, there is a dearth of well-conducted natural experimental studies examining the causal effect of changing urban green space on physical activity and wellbeing. This is especially true in older adults and in the United Kingdom. This paper describes a natural experimental study to evaluate the effect of four small-scale urban street greening interventions on older adults' physical activity and wellbeing over a 1-year period, relative to eight matched comparison sites. All sites are located in deprived urban neighbourhoods in Greater Manchester, United Kingdom. METHODS: Components of the interventions include tree and flower planting, and artificial tree decorations. Eight unimproved comparison sites were selected based on a systematic process of matching using several known objective and subjective environmental correlates of physical activity in older adults. The outcome measures are physical activity and two other behavioural indicators of wellbeing (Connect: connecting with other people; and Take Notice: taking notice of the environment), collected using a newly developed observation tool. The primary outcome is Take Notice behaviour due to largest effects on this behaviour being anticipated from improvements in the aesthetic quality of green space at the intervention sites. Baseline data collection occurred in September 2017 before the interventions were installed in November 2017. Follow-up data collection will be repeated in February/ March 2018 (6 months) and September 2018 (12 months). DISCUSSION: The present study permits a rare opportunity to evaluate the causal effects of small-scale changes in urban green space in an understudied population and setting. Although the interventions are expected to have small effects on the outcomes, the present study contributes to developing natural experiment methodology in this field by addressing key methodological weaknesses causing high risk of bias in previous natural experimental studies. Key improvements to reduce risk of bias in the present study are rigorous matching of multiple comparison sites and appropriate statistical control of key confounders. TRIAL REGISTRATION: Retrospectively registered with study ID NCT03575923 . Date of registration: 3 July 2018.

A century of sprawl in the United States.

The urban street network is one of the most permanent features of cities. Once laid down, the pattern of streets determines urban form and the level of sprawl for decades to come. We present a high-resolution time series of urban sprawl, as measured through street network connectivity, in the United States from 1920 to 2012. Sprawl started well before private car ownership was dominant and grew steadily until the mid-1990s. Over the last two decades, however, new streets have become significantly more connected and grid-like; the peak in street-network sprawl in the United States occurred in ∼ 1994. By one measure of connectivity, the mean nodal degree of intersections, sprawl fell by ∼ 9% between 1994 and 2012. We analyze spatial variation in these changes and demonstrate the persistence of sprawl. Places that were built with a low-connectivity street network tend to stay that way, even as the network expands. We also find suggestive evidence that local government policies impact sprawl, as the largest increases in connectivity have occurred in places with policies to promote gridded streets and similar New Urbanist design principles. We provide for public use a county-level version of our street-network sprawl dataset comprising a time series of nearly 100 y.

[A spatially explicit analysis of traffic accidents involving pedestrians and cyclists in Berlin]. / Eine räumlich differenzierte Analyse von Verkehrsunfällen mit Radfahrer- und Fußgängerbeteiligung in Berlin.

BACKGROUND: In many German cities and counties, sustainable mobility concepts that strengthen pedestrian and cyclist traffic are promoted. From the perspectives of urban development, traffic planning and public healthcare, a spatially differentiated analysis of traffic accident data is decisive. OBJECTIVES: 1) The identification of spatial and temporal patterns of the distribution of accidents involving cyclists and pedestrians, 2) the identification of hotspots and exploration of possible underlying causes and 3) the critical discussion of benefits and challenges of the results and the derivation of conclusions. MATERIAL AND METHODS: Spatio-temporal distributions of data from accident statistics in Berlin involving pedestrians and cyclists from 2011 to 2015 were analysed with geographic information systems (GIS). RESULTS: While the total number of accidents remains relatively stable for pedestrian and cyclist accidents, the spatial distribution analysis shows, however, that there are significant spatial clusters (hotspots) of traffic accidents with a strong concentration in the inner city area. CONCLUSIONS: In a critical discussion, the benefits of geographic concepts are identified, such as spatially explicit health data (in this case traffic accident data), the importance of the integration of other data sources for the evaluation of the health impact of areas (traffic accident statistics of the police), and the possibilities and limitations of spatial-temporal data analysis (spatial point-density analyses) for the derivation of decision-supported recommendations and for the evaluation of policy measures of health prevention and of health-relevant urban development.

Changing and Differentiated Urban Landscape in China: Spatiotemporal Patterns and Driving Forces.

Urban landscape spatiotemporal change patterns and their driving mechanisms in China are poorly understood at the national level. Here we used remote sensing data, landscape metrics, and a spatial econometric model to characterize the spatiotemporal patterns of urban landscape change and investigate its driving forces in China between 1990 and 2005. The results showed that the urban landscape pattern has experienced drastic changes over the past 15 years. Total urban area has expanded approximately 1.61 times, with a 2.98% annual urban-growth rate. Compared to previous single-city studies, although urban areas are expanding rapidly, the overall fragmentation of the urban landscape is decreasing and is more irregular and complex at the national level. We also found a stair-stepping, urban-landscape changing pattern among eastern, central, and western counties. In addition, administrative level, urban size, and hierarchy have effects on the urban landscape pattern. We also found that a combination of landscape metrics can be used to supplement our understanding of the pattern of urbanization. The changes in these metrics are correlated with geographical indicators, socioeconomic factors, infrastructure variables, administrative level factors, policy factors, and historical factors. Our results indicate that the top priority should be strengthening the management of urban planning. A compact and congregate urban landscape may be a good choice of pattern for urban development in China.

Urban vegetation and heat-related mortality in Seoul, Korea.

Urban areas are particularly vulnerable to heat-related health outcomes. Simultaneous trends of climate change and urbanization may increase the urban heat-related health burden. We investigated the effects of urban vegetation on heat-related mortality, and evaluated whether different levels of vegetation and individuals' characteristics affect the temperature-mortality associations within Seoul, Korea 2000-2009. We used Normalized Difference Vegetation Index (NDVI) to assess the urban vegetation within Seoul. We applied an overdispersed Poisson generalized linear model with interaction term between temperature and indicator of NDVI group (categorized in 3 levels) to assess the effect modification of the temperature-mortality association by urban vegetation. We conducted stratified analysis to explore whether associations are affected by individual characteristics of sex and age. The association between total mortality and a 1°C increase in temperature above the 90th percentile (25.1°C) (the "heat effect") was the highest for gus with low NDVI. The heat effect was a 4.1% (95% confidence interval (CI) 2.3, 5.9%), 3.0% (95% CI 0.2, 5.9%), and 2.2% (95% CI -0.5, 5.0%) increase in mortality risk for low, medium, and high NDVI group, respectively. Estimated risks showed similar effects by sex and age. Our findings suggest a higher mortality effect of high temperature in areas with lower vegetation in Seoul, Korea.

Climate, water and tourism: causes and effects of droughts associated with urban development and tourism in Benidorm (Spain).

In this paper, we analyse the relationship between climate, tourism and water in Benidorm (Spain), an international icon of Fordist tourism (mass tourism). In particular, we have studied the causes and effects of the water supply droughts Benidorm has suffered since becoming a major holiday destination. For this purpose, we consulted the local press in Benidorm over the period 1969-2003. Using qualitative and quantitative geographical techniques, we found that the water supply in the area has managed to keep up with rapidly increasing demand, with only occasional imbalances and periods of crisis. We focused in particular on the causes and effects of the water supply crisis of 1978, a moment of great uncertainty in the history of Benidorm as a holiday resort. We also examined the influence of atmospheric conditions on precipitation levels and how these precipitation levels affect the water supply. Our results highlight the importance of intense rainfall episodes associated with easterly winds, which provided large inputs for Benidorm's water supply system (Marina Baja Water Consortium). We also found that the water supply crisis of 1978 resulted in serious economic losses for Benidorm and damaged its image as a holiday destination and that the city is now less vulnerable to variations in the climate, as a result of its search for new water resources (both surface and ground water resources and from other nonconventional sources).

Geospatial quantification and analysis of environmental changes in urbanizing city of Kolkata (India).

Over the past five decades, the fragile wetland ecosystem surrounding the city of Kolkata has witnessed extensive changes in the name of urban development. In this study, we elaborate relationships among biophysical parameters and land surface temperature (LST) in Kolkata city and nearby surrounding areas where rapid urbanization has occurred. LST and associated surface physical characteristics were assessed using Landsat images acquired for the years 1989, 2006, and 2010. The satellite data was used to study the spatiotemporal urban footprint and correlation among normalized difference vegetation index (NDVI), normalized difference built-up index (NDBI), normalized difference water index (NDWI) and LST. Land use land cover (LULC) maps prepared using supervised classification had overall accuracy of 90, 88, and 86 % and kappa coefficient of 0.8726, 0.8455, and 0.8212 for 1989, 2006, and 2010, respectively. The spatial expansion as a consequence of increasing urban population is 108.94 km(2) over past two decades. The urban built-up in and around the city extends up to 88.71 km(2) in 1989, 144.64 km(2) in 2006, and 197.65 km(2) in 2010. These changes have attributed in elevating surface temperature in the study region. Analysis of biophysical parameters shows LST and NDBI having a positive correlation, LST and NDVI having negative correlation, while NDBI and NDWI having a perfectly negative correlation. Satellite estimated temperatures of the surface show a warming trend evident from increasing mean surface temperature values from 27.36 °C in 1989 to 30.025 °C in 2006 and 33.023 °C in 2010. The magnitude and extent of the estimates of LST are consistent with the urbanization pattern throughout the city and adjoining areas.

Effect of development on water quality for seven streams in North Carolina.

In this study, baseflow and storm discharges were monitored in seven watersheds of varying development density to document the effects of development on stream water quality. In addition, two of the watersheds contained package wastewater treatment facilities, which were evaluated as an alternative to residential on-site septic systems. Monthly grab samples of baseflow and flow-proportional samples of storm event discharge were collected and analyzed for nitrogen, phosphorus, sediment, and bacteria. For the five watersheds without wastewater treatment facilities, a significant linear relationship was documented between fecal coliform and enterococci levels in baseflow samples and the percentage of residential or impervious area. For the two watersheds with wastewater discharge, bacteria levels were significantly greater than those from the two relatively undeveloped watersheds. These results indicate that bacteria levels increased with increasing residential development even if many of the septic systems were replaced by a community wastewater treatment system. Computed annual export rates for ammonia nitrogen (NH3-N) were correlated to the percentage of impervious surfaces in the watersheds, while the rates for other nitrogen forms, total phosphorus, and total suspended sediment were not. Annual export rates from the two mostly undeveloped watersheds were greater than a compilation of rates for undeveloped areas across the USA. Export from the four watersheds with more than 68 % residential land use was less than those reported from local and national studies of residential areas.

Ambient urban N deposition drives increased biomass and total plant N in two native prairie grass species in the U.S. Southern Great Plains.

Remnants of native tallgrass prairie experience elevated atmospheric nitrogen (N) deposition in urban areas, with potential effects on species traits that are important for N cycling and species composition. We quantified bulk (primarily wet) inorganic N (NH4+-N + NO3--N) deposition at six sites along an urban development gradient (6-64% urban) in the Dallas-Fort Worth metropolitan area from April 2014 to October 2015. In addition, we conducted a phytometer experiment with two common native prairie bunchgrass species--one well studied (Schizachyrium scoparium) and one little studied (Nasella leucotricha)--to investigate ambient N deposition effects on plant biomass and tissue quality. Bulk inorganic N deposition ranged from 6.1-9.9 kg ha-1 yr-1, peaked in spring, and did not vary consistently with proportion of urban land within 10 km of the sites. Total (wet + dry) inorganic N deposition estimated using bulk deposition measured in this study and modeled dry deposition was 12.9-18.2 kg ha-1 yr-1. Although the two plant species studied differ in photosynthetic pathway, biomass, and tissue N, they exhibited a maximum 2-3-fold and 2-4-fold increase in total biomass and total plant N, respectively, with 1.6-fold higher bulk N deposition. In addition, our findings indicate that while native prairie grasses may exhibit a positive biomass response to increased N deposition up to ~18 kg ha-1 yr-1, total inorganic N deposition is well above the estimated critical load for herbaceous plant species richness in the tallgrass prairie of the Great Plains ecoregion and thus may negatively affect these plant communities.

The spatial coupling effect between urban street network's centrality and collection & delivery points: A spatial design network analysis-based study.

The sustainable development of collection and delivery points and urban street network is an important consideration of logistic planners. Urban street networks have a significant impact on collection and delivery points' location, but the spatial relationship between the centrality of urban street network and collection and delivery points has not been studied using spatial design network analysis. In a multiple centrality assessment model, we used point of interest and street network data to evaluate the location of two types of collection and delivery points and the centrality of streets in Nanjing city, based on four indicators: closeness, betweenness, severance, and efficiency. Then, kernel density estimation and spatial autocorrelation are used to study spatial patterns of distribution and centrality coupling effects of urban street network and collection and delivery points. The results show that the centrality of Nanjing streets has a big influence on the location of the collection and delivery points, and the directions of different types of centrality also vary. The location of the Cainiao Stations are largely related to closeness, followed by betweenness, severance, and efficiency. China Post Stations and street centrality have a weak correlation between efficiency and severance, but no correlation between closeness and betweenness. Our results can help logistics enterprises and urban planners to develop collection and delivery points' network based on the urban street network.

Feature extraction and machine learning techniques for identifying historic urban environmental hazards: New methods to locate lost fossil fuel infrastructure in US cities.

U.S. cities contain unknown numbers of undocumented "manufactured gas" sites, legacies of an industry that dominated energy production during the late-19th and early-20th centuries. While many of these unidentified sites likely contain significant levels of highly toxic and biologically persistent contamination, locating them remains a significant challenge. We propose a new method to identify manufactured gas production, storage, and distribution infrastructure in bulk by applying feature extraction and machine learning techniques to digitized historic Sanborn fire insurance maps. Our approach, which relies on a two-part neural network to classify candidate map regions, increases the rate of site identification 20-fold compared to unaided visual coding.