Functional Urban Areas Research Articles

Understanding the Correlation between Landscape Pattern and Vertical Urban Volume by Time-Series Remote Sensing Data: A Case Study of Melbourne

Urbanization is changing the world’s surface pattern more and more drastically, which brings many social and ecological problems. Quantifying the changes in the landscape pattern and 3D structure of the city is important to understand these issues. This research study used Melbourne, a compact city, as a case study, and focused on landscape patterns and vertical urban volume (volume mean (VM), volume standard deviation (VSD)) and investigate the correlation between them from the scope of different scales and functions by Remote Sensing (RS) and Geographic Information System (GIS) techniques. We found: (1) From 2000 to 2012, the landscape pattern had a trend of decreasing fragmentation and increasing patch aggregation. The growth of VM and VSD was more severe than that of landscape metrics, and presented a “high–low” situation from the city center to the surroundings, maintaining the structure of “large east and small west”. (2) Landscape pattern was found closely associated with the urban volume. In the entire study area, landscape pattern patches with low fragmentation and high aggregation were directly proportional to VM with high value, which represented high urbanization, and patches with high connectivity and fragmentation had a positive relationship with high VSD, which represented strong spatial recognition. (3) The urban volumes of different urban functional areas were affected by different landscape patterns, and the analysis based on the local development situation can explain the internal mechanism of the interaction between the landscape pattern and the urban volume.

Accessibility of public services in the age of ageing and shrinking population: are regions following trends

ABSTRACT This paper investigates the characteristics and functional-demographic diversity of municipalities in Poland that use spatial data. It answers the question about the relationship between accessibility to services of general interest (SGI; public administration, child-care, educational, medical, and cultural services) in municipalities and their demographic conditions. Demographic literature devotes much space to demographic transformations in the context of their underlying causes and spatial variations and to the impact of these changes. Meanwhile, transport-focused approaches concentrate on the spatial accessibility of SGI themselves, the methods for measuring them and the various methodologies employed. This study combines these two study areas in order to present the broadest possible approach to the accessibility of SGI among communities at different stages of demographic advancement. We found that the nature of demographic processes is associated with the level of accessibility to SGI. Notably, accessibility to educational and medical services in depopulating areas is better than in ageing areas. The opposite is true for cultural services. The poorest accessibility affects those communities where the two above demographic processes overlap. There is clear variation in the accessibility of SGI: functional urban areas having the best accessibility and remote areas the worst accessibility .

Multisource Data-Driven Visual Analysis of Urban Crowd Travel

Many functional areas have been formed in the development of the city, and the gathering of taxis can basically reflect the travel situation of the crowd. Combining urban functional areas and taxi GPS data to analyze crowd travel conditions can provide decision support for the construction of smart cities. Therefore, this paper analyzed the travel situation of crowd in Changsha urban area based on multi-source data. First, this paper clusters the distribution of public transit stations in Changsha, and then imports the geographic location information of the cluster centers into the Voronoi diagram in ArcGis to divide the urban area of Changsha. Then the divided areas and Point of interest (POI) data are counted and analyzed to obtain the functionality of each area. Finally, the taxi GPS data is clustered according to the time period, and the cluster center is mapped to the urban functional area, to analyzed the crowd clustering situation of each functional area in Changsha in different time periods.

Геоинформационное обеспечение изучения размещения зарубежных ТНК в глобальных городах

The article discusses the experience of assessing the location of foreign TNCs in global cities as a significant factor in the field of environmental, economic and social aspects of sustainable development of urban areas. A number of initial theoretical models are proposed from the standpoint of the center-peripheral approach and a conceptual scheme of geoinformation and cartographic support of the study is presented, the main stages of its implementation are revealed. The databases of the European Commission’s Joint Research Center (GHS Urban Center Database, GHS-UCDB) and (GHS Functional Urban Areas, GHS-FUA) were used to get an idea of the real models of the intracity location of large business in the delimitation of the boundaries of agglomerations and their separate zones. To determine the composition of TNC divisions, Forbes 2000 data for 2020 and information from corporate websites on the branch network with geographic reference from the Craft.co reference service were used. In total, 55 global cities of the alpha group and more than 12 thousand foreign branches of TNCs were involved in the analysis. The processing and systematization of the obtained data was carried out using the object-relational database management system (RDBMS) PostgreSQL and the PostGIS extension. The visualization of the research results based on the consolidation of tabular data and spatial relationships using QGIS. Comparative analysis showed the effectiveness of the developed technique. As a result of its application, the overall scale of the presence of big business in the global cities of the alpha group and a significant gap between leaders and outsiders were determined. The absence of a universal model for the zonal distribution of TNCs in the urban space was revealed, the basic invariants of which were visualized using the example of a number of centers. The presented developments can contribute to the development of the direction of microgeographic research in geo-urban studies. In practice, the methodology can be useful for modernizing the assessment of the quality of the urban environment and the conditions for its formation as part of the implementation in the Russian Federation of the national project “Housing and Urban Environment”.

Obszary intensywnych powiązań funkcjonalnych miast na prawach powiatu w Polsce – autorska metoda delimitacji = Areas of strong functional linkage of Polish cities granted county status – the authors’ own method of delimitation

Spatial mobility of the population is a key factor allowing for the delimitation of functional areas and the identification of ranges of impact of given spatial units. The work detailed here has built on this idea by seeking to identify areas of strong functional linkage in the cities in Poland that have been granted the status of powiat (i.e. unit at the “county” level of administration). In this context, the paper also offers a critical analysis of other, best-known approaches to the delimitation of towns and cities in Poland. The identification of areas characterised by strong functional linkage is achieved by reference to generally-available data, i.e. statistics relating to commutes to work, as well as internal migration leading to permanent residency status. Overall, areas of srong functional linkage are here delimited by reference to: (1) areas of emigration or immigration relating to thecities granted county status, where these are the source and/or destination when it comes to internal migration leading to permanent residency; (2) areas of departure and arrival where commutes to and from the aforesaid cities granted county status are concerned, with account taken of additional relations relating to volumes of flows in a ‘city–rural area’ configuration. Our analysis was performed at NUTS-5 level, hence the exclusion of cities not enjoying county status. It is against the background of existing literature reports on means of identifying areas of functional linkage for Polish cities that the work detailed here may establish a basis for discussing alternative approaches. Here the authors offer their own method of identifying areas of strong functional linkage, from the point of view of people’s spatial mobility. This approach takes account of specifically Polish aspects of the phenomenon’s development. Indeed, analyses confirm that the approach proposed is very much linked to the functional urban areas of regional centres. However, complete objectivisation (i.e. a lack of subjectivity or even arbitrary decisions) represents a significant attribute of the approach in question, with this being desirable when it comes to research being replicated.

Urban expansion of the largest cities in Bosnia and Herzegovina over the period 2000-2018

The paper analyses the databases Urban Atlas (UA), Imperviousness, and CORINE Land Cover (CLC) for the largest cities in Bosnia and Herzegovina (B&H). The UA database contains information for five functional urban zones with more than 100,000 inhabitants: Sarajevo, Banja Luka, Tuzla, Mostar, and Zenica. The Imperviousness database is related to the subclasses of the urban atlas because the impermeability percentage has been used for a more detailed classification within the discontinuous urban area. The CLC database provides insight into the intensity of expansion of these cities during three six-year periods: 2000-2006, 2006-2012, and 2012-2018. The research has been used to analyse the expansion of urban zones, the structure, and form of cities, and the impact of urban expansion on the surrounding area. The results of the research show that, despite the negative demographic trends, there is a trend of urban expansion in B&H, mainly over the agricultural land. According to the CLC database in the period 2000-2018, artificial areas increased in spatial coverage from 1.35% to 1.7%, and urban fabric from 0.99% to 1.27%. The Imperviousness database shows that in 2018sealed areas covered 1.59% and built-up areas 0.8% of the territory of B&H. The 2013 census showed that the number of inhabitants in all five functional urban areas decreased compared to 1991, but despite that fact, the expansion of urban zones continues with a weaker or stronger intensity. So far, there has been no research on urban development based on the high-resolution layers UA and Imperviousness database in B&H, so that such research is the most significant contribution of this article.

Research on the Coupling Coordination Relationships between Urban Function Mixing Degree and Urbanization Development Level Based on Information Entropy.

With the rapid development of urbanization, the blind expansion of urban space has led to a series of social problems. In this process, the degree of urban function mixing affects the urbanization development level, making it particularly important to study the degree of coupling coordination between the two aspects. In this paper, taking Beijing as an example, we use urban point of interest (POI) data and taxi GPS trajectory data to calculate the urban POIs’ spatial entropy and taxis’ temporal entropy, based on the information entropy. We use the POIs’ spatial entropy and taxis’ temporal entropy to measure the urban function mixing degree. Also, the model of coupling coordination degree is used to measure the degree of coupling coordination between the urban function mixing degree and the urbanization development level. The results indicate the following: First, the POIs’ spatial entropy and taxis’ temporal entropy have significant regional imbalances. On the whole, both show a declining pattern when moving from the central urban area to the outer suburbs. The urban function mixing degree and urbanization development level are also higher in the central urban area than in the outer suburbs. Second, the coupling coordination among the urbanization development level, POIs’ spatial entropy, and taxis’ temporal entropy is distributed unevenly across various regions, which means that the three types of coupling coordination are in balanced development in the central urban area, but in unbalanced development in the outer suburbs. Third, from the perspective of spatial correlation characteristics, the higher is the degree of spatial agglomeration, the higher are the urban function mixing degree and urbanization development level, and the higher is the coupling coordination degree among the urbanization development level, POIs’ spatial entropy, and taxis’ temporal entropy. Therefore, relevant departments should plan the construction of urban functional areas reasonably, according to the degree of coupling coordination between the urban function mixing degree and the urbanization development level in different regions, so as to realize the healthy and sustainable development of a city.

Evaluating Street Greenery by Multiple Indicators Using Street-Level Imagery and Satellite Images: A Case Study in Nanjing, China

Street greenery plays an essential role in improving the street environment and residents’ health. The evaluation of street greenery is of great value to establish environmentally friendly streets. The evaluation indicators of present studies evaluating street greenery were relatively single, either the Green View Index (GVI) or Normalized Difference Vegetation Index (NDVI), which cannot describe the greenery condition in its entirety. The objective of this study is to assess the street greenery using multiple indicators, including GVI, NDVI, and Vegetation Structural Diversity (VSD). We combined street view images with a semantic segmentation method to extract the GVI and VSD and used satellite images to calculate the NDVI in the urban area of Nanjing, China. We found correlations and discrepancies of these indicators using statistical analyses in different urban districts, functional areas, and road levels. The results indicate that: (1) the GVI and NDVI are strongly correlated in open spaces, whereas weakly correlated in residential and industrial lands, (2) the areas with higher VSD are mainly located in the new city, whereas the VSD in the old city is lower, and a weak negative correlation exists between the GVI and VSD in the research area, and (3) the old city has a higher GVI level compared to the new city on the main road, whereas the new city has a higher GVI level than the old city on the branch road. Compared with the GVI, the trend of VSD in the old city and the new city is relatively consistent. Our findings suggest that considering multiple indicators of street greenery evaluation can provide a comprehensive reference for building more human-friendly and diversified street green belts.

Classification of Urban Functional Areas From Remote Sensing Images and Time-Series User Behavior Data

Urbanization is accelerating at a rapid rate, which has introduced many challenges, especially in the field of urban planning. Under the backdrop of global urbanization, some cities are particularly vulnerable to climate change and natural disasters that are influenced by unplanned urban expansion. Rational planning of urban functional areas needs to be strengthened to improve the scientific approach of urban planning and urbanization. In this study, the classification of urban functional areas based on dual-modal data (i.e., remote sensing image and user behavior data) was implemented using machine learning (ML) algorithms. After the set test, the classification accuracy of urban functional areas reached 82.45%. Through analysis, it could be concluded that the use of data of two modalities achieved a higher classification accuracy than that achieved by using data of a single modality. The data of the two modalities complement each other, and the use of ML algorithms to train such data can yield good results.

Exploring the Attractiveness of Residential Areas for Human Activities Based on Shared E-Bike Trajectory Data

Human activities generate diverse and sophisticated functional areas and may impact the existing planning of functional areas. Understanding the relationship between human activities and functional areas is key to identifying the real-time urban functional areas based on trajectories. Few previous studies have analyzed the interactive information on humans and regions for functional area identification. The relationship between human activities and residential areas is the most representative for urban functional areas because residential areas cover a wide range and are closely connected with human life. The aim of this paper is to propose the CARA (Commuting Activity and Residential Area) model to quantify the correlation between human activities and urban residential areas. In this model, human activities are represented by hot spots extracted by the Gaussian Mixture Model algorithm while residential areas are represented by POI (point of interest) data. The model shows that human activities and residential areas present a logarithmic relationship. The CARA model is further assessed by retrieving urban residential areas in Tengzhou City from shared e-bike trajectories. Compared with the actual map, the accuracy reaches 83.3%, thus demonstrating the model’s reliability and feasibility. This study provides a new method for functional areas identification based on trajectory data, which is helpful for formulating the urban people-oriented policies.

Spatial Distribution Characteristics and Source Apportionment of Soil PAHs in Shizuishan City Based on GIS and PMF Model

With the acceleration of urbanization and industrialization, the content and pollution of polycyclic aromatic hydrocarbons (PAHs) in urban soils have been sources of widespread concern. Taking Shizuishan City as an example, the spatial distribution characteristics of PAHs in 156 surface soil samples (0-20 cm) from eight urban functional areas were analyzed. Single factor and Nemero composite indices, as well as a lifetime cancer risk increment model were used to evaluate PAHs pollution in soils. The sources of PAHs were analyzed using the positive matrix factorization (PMF) model. The results showed that the mean value of PAHs in the surface soil of Shizuishan City was 489.82 ng·g-1 and the coefficient of variation of 15 PAHs except for Pyr were more than 100%, indicating strong variation. The PAH contents of urban surface soils in different functional areas showed the following:traffic area (1217.61 ng·g-1) > industrial area (809.58 ng·g-1) > park (273.66 ng·g-1) > cultural and educational area (268.18 ng·g-1) > commercial area (240.05 ng·g-1) > agricultural area (226.81 ng·g-1) > medical area (211.90 ng·g-1) > residential area (183.49 ng·g-1). The Nemero composite index showed that 82.58% of the samples had no pollution, and the proportion of slight, mild, and moderate pollution were 6.45%, 4.52%, and 0.65%, respectively. Only 5.8% of the samples had serious pollution. The results of health risk assessment showed that skin contact and ingestion were the main routes of PAH exposure in soil, and the health risk was acceptable. Source analysis showed that the main sources of PAHs in Shizuishan City were traffic emissions, coal combustion, mixed biomass/heavy oil combustion, and oil sources, with contribution rates of 10.5%, 36.6%, 50.3%, and 2.6% respectively, and most of the high values were distributed in industrial or coal production areas. These results could provide reference for the study of soil pollution in industrial cities, and play an important role in preventing soil pollution, ensuring the environmental quality of the soil and human health and safety.

Rozwój przestrzenny byłych miast wojewódzkich w Polsce. Studium przypadku Krosna, Przemyśla i Tarnobrzega

Decentralizacja ustroju terytorialnego państwa wywarła ogromny wpływ na rozwój miast na przełomie XX i XXI w. Dotyczy to zwłaszcza byłych stolic województw „zdegradowanych” do funkcji miast na prawie powiatu, przed którymi stanęło wiele wyzwań natury społeczno-gospodarczej, co znalazło odzwierciedlenie m.in. w ich rozwoju przestrzennym. Celem opracowania jest zidentyfikowanie uwarunkowań, cech wspólnych i różnic, a także wskazanie kierunków zmian w procesie rozwoju przestrzennego byłych miast wojewódzkich w Polsce. W pracy odniesiono się do takich zagadnień, jak: 1) wpływ rozszerzenia granic administracyjnych na zmiany struktury funkcjonalno-przestrzennej; 2) stymulanty i destymulanty rozwoju przestrzennego; 3) kształtowanie struktury przestrzennej w nawiązaniu do historycznego rozwoju miast oraz zapisów dokumentów strategiczno-planistycznych; 4) miejskie obszary funkcjonalne; 5) kierunki rozwoju przestrzennego analizowanych miast w przyszłości. Odpowiadają one układowi celów szczegółowych. Efekty niniejszej pracy są dwojakie. W aspekcie implementacyjnym ukazano wpływ transformacji ustrojowej, reform administracyjno-terytorialnych oraz prowadzonej polityki przestrzennej na rozwój miast będących do 1998 r. stolicami województw, tj. Krosna, Przemyśla i Tarnobrzega, położonych obecnie w województwie podkarpackim. W aspekcie poznawczym opracowano modele rozwoju przestrzennego tych miast.

Exploring the functional area approach in EU urban strategies

A vast literature has investigated processes of spatial reconfiguration, contributing to the emergence of a ‘new urban question’ that not only reframes traditional urban issues but also challenges our understanding of what cities are today. Be that as it may, the ‘European city model’ still remains current, particularly with regards to the institutional role of cities as they are increasingly considered to be relevant policy actors. This urban paradox gives new emphasis to the urban regional scale and urgently calls for the two dimensions to be connected both in terms of territorial dynamics and policy formulation. This paper addresses the topic by focusing on the functional area approach promoted by the European Union regional policy discourse, and by discussing how it shapes and legitimates new spatial configurations, with implications for urban analysis and policy approaches. The paper is based on the analysis of a database which gathers nearly 1000 strategies for Sustainable Urban Development funded by the EU between 2014-2020, and features a significant number of functional areas. The analysis reveals that the functional area approach does not only apply to metropolitan areas, big cities, or Functional Urban Areas, but can also be used for different types of territories, beyond metropolitan areas. It also underscores the need for more extensive research on what spatialities and territorial arrangements emerge from this process.

Multi-Methodological Integrated Approach for the Assessment of Diffuse Pollution Background Levels (DPBLs) in Functional Urban Areas: The PCE Case in Milano NW Sector

The Milano Metropolitan Area (named FUA Functional Urban Area) has a history of heavy industrialization causing a large portion of area being affected by significant diffuse contaminations of soil and groundwater. Among the various contaminants, chlorinated solvents (e.g. tetrachloroethylene and trichloroethylene) are the most used in industrial processes and represent the major cause of groundwater pollution within the Functional Urban Area. The background diffuse contamination generated by these pollutants is so persistent and widely spread that makes extremely challenging to identify the sources responsible for their release. Such background contamination originates from the overlapping of both known sources (Point Sources), associated to specific high release of contamination, and unknown small sources (Multiple Point Sources), clustered within a large area, whose release is low but persistent. The aim of this paper is to present the methodology, developed within the framework of the AMIIGA Project (Interreg Central Europe Grant N° CE32), which combines multivariate statistical analysis and groundwater numerical modeling in order to separate the point sources (PS) contribution from the background diffuse contamination, and supporting Public Authorities in the management of groundwater remediation. A methodological work-flow is proposed guiding local and regional Institutions to use the methodology (i.e. exploratory analysis of big dataset, simulation of groundwater flow and transport, multivariate and geostatistical analysis) to assess Diffuse Pollution Background Levels (DPBLs) in large urbanized areas.

Policentrismo e Cooperações Intermunicipais: um estudo em regiões de baixa densidade demográfica no norte do Rio Grande do Sul/Brasil

O artigo debate o conceito de policentrismo e de áreas funcionais urbanas em regiões de baixa densidade demográfica do sul do Brasil. Evidencia que diante da polissemia do conceito de Policentrismo, há dificuldades em visualizar o conceito em ação no norte do Rio Grande do Sul (RS), dada a redução populacional nas suas pequenas centralidades e a reestruturação produtiva atual desta rede urbana. As regiões funcionais, em caráter normativo, no entanto, encontram-se fortalecidas nos polos regionais de Passo Fundo e de Erechim/RS, como nós desta rede urbana e polos de fluxos centrípetos, esboçado aqui na pendularidade por trabalho e estudo. É urgente entender a superação das políticas públicas que se restringem as delimitações político-administrativas municipais, de forma a avançar os estudos em torno de fronteiras dinâmicas, de planejamentos cada vez mais regionais e de objetivos mais cooperativos. Frente a situação de decréscimo populacional, as redes policêntricas e o associativismo municipal demonstram-se ser boas possibilidades, como fontes inovadoras e desafiantes de novas governanças.

Extending the concept of city for delineating large urban regions (LUR) for the cities of the world

Cities’ delineation remains a hot topic of debate in a time where comparisons between cities are becoming increasingly based on different issues that address various scales of interventions and thus different concepts of cities. Aiming to compare cities and their insertion into globalization, we suggest that the “urban field of influence” is the best way to approach cities for this specific perspective. However, after reviewing the different existing possible concepts, we extend this concept with four complementary approaches: political entities, morphological agglomerations, functional urban areas and conurbations/Mega city regions. We discuss the top-down and bottom-up existing initiatives launched at the world scale and then use a mixed top-down and bottom-up approach to propose a new delineation of a large urban region (LUR), denoting a concept close to the conurbation or Mega city-region concept. The compositions of these LURs are published as an initial draft of an open database that can be criticized and improved by further contributions, suggesting the need for further critical comments and feed-back to improve them.

Dispersión y artificialización de las Áreas Urbanas Funcionales Españolas. Propuesta tipológica basada en el Programa Europeo Copernicus

European institutions focus their attention on urban areas, as an example of ecosystems, which are constantly changing. Nowadays peri-urban areas are the most important parts in urban areas. Peri-urban areas are complex and multi-functional spaces and they develop a fuzzy urban sprawl related to unsustainable ways of life. On the other hand, peri-urban areas suffer pressure associated to a dynamic artificialization process in the territory. Nevertheless, peri-urban areas must sure the ecosystem services in the whole area. Against this background, the article aims to calculate the degree or artificialization of functional urban areas in Spain, as a base to propose a classification of the main land uses. The study shows spatial patterns of many urban systems and it permits us to advance in the knowledge of urban peripheries, which is very important to face the national urban agenda

Null-Space Monte Carlo Particle Backtracking to Identify Groundwater Tetrachloroethylene Sources

Groundwater in urban areas around the globe happens to be contaminated by toxic substances. Among the various sources of contamination, industries determine the heaviest impacts when toxic compounds are released in the underground, mainly through leaking tanks or pipelines. Some contaminants (typically chlorinated hydrocarbons) tend to persist within the underground and are hard to biodegrade. As a result, substances that leaked decades ago are still impacting groundwater. Milano and its hinterland (Functional Urban Area) are a good example of an area that has been hosting for over a century, industries of all dimensions, many of them contributing chlorinated hydrocarbons in the underground. While the position of the biggest industrial facilities is well known, many smaller sources are hard to identify in many cases where direct surveys haven’t been undertaken. Furthermore, the overlapping effects of big, small, known and unknown sources on groundwater contamination makes it hard to identify the contribution of each. In order to identify the contribution of several Point Sources responsible of Tetrachloroethylene contamination in Public Water Supply Wells, a numerical model (MODFLOW-2005) has been implemented and calibrated (PEST) in the Northwestern portion of Milano Functional Urban Area. In contaminant transport modeling, the deterministic approach is still favored over the stochastic because of the simplicity of its application. Nevertheless, the latter is considered by the authors as the suitable dealing with problems characterized by high uncertainty, such as hydrogeological parameters distribution. Adopting a Null-Space Monte Carlo analysis, 400 different sets of hydraulic conductivity fields have been randomly generated, of which only 336 have been selected using an objective function threshold. Subsequently, a particle back-tracking has been performed for each of the accepted hydraulic conductivity fields, by placing particles in a contaminated well. The number of particle passages is considered as being proportional to the contribution of each unknown Point Source to the Tetrachloroethylene contamination identified in the target well. The study provides a methodology to help Public Authorities to locate the most probable than not area responsible to the Tetrachloroethylene contamination detected in groundwater and to focus environmental investigations in specific sectors of Milano city.

Os Sertões do Piauí Dinamização: Dilemas e Desafios para Gestão Urbana em uma Cidade de Comando Regional Piauiense

Objetivo do estudo: Este artigo objetiva apontar e discutir os dilemas e desafios da gestão urbana que Picos/PI, vem experimentando, considerando seu atual Plano Diretor.Metodologia/abordagem: a construção da pesquisa está pautada em dois momentos: o primeiro, de base teórica, entre diferentes pensadores, na literatura urbano e regional. O segundo, de natureza qualitativa, cuja referência é a seleção, interpretação e análise técnica de documentos legais do município de Picos/PI: Plano Diretor vigente e a Lei municipal do Uso do Solo.Originalidade/Relevância: O dinamismo urbano e regional ocorrido em muitas cidades localizadas, fora dos quadros metropolitanos do Brasil, desde a década de 1980, tem motivado a constituição de uma rica agenda de pesquisas acadêmicas, cuja direção tem se dado sobre os processos de gestão urbana e análises sobre os diferentes instrumentos de ordenamento urbano. Muitas reflexões têm questionado o futuro daquelas cidades, a partir da existência e execução de seus Planos Diretores. Nesse contexto, aparece Picos/PI, uma Cidade de Comando Regional, qualificada, pelas fortes interações espaciais, bem como, pela destacada capacidade, de uma Área Urbana Funcional (FUA), nos sertões do estado do Piauí, Brasil.Principais resultados: O principal dilema, repousa na observação de que as legislações analisadas possuem uma série de inconformidades com a organicidade da referida cidade. Frente a isso, o grande desafio é essencialmente político: a urgente atualização Plano Diretor, bem como, da sua efetiva aplicação, com vistas à resolução de uma série de demandas, de organização espacial, no contexto intraurbano.Contribuições teóricas/metodológicas: Analise e interpretação dos papeis urbanos na região e os rebatimentos espaciais a partir da concepção de Cidades de Comando regional.

PCE point source apportionment using a GIS-based statistical technique combined with stochastic modelling

To meet the continuous growth of urbanised areas with the ever-increasing demand for safe water supplies, the implementation of new scientifically based methodologies can represent a key support for preventing groundwater quality deterioration.In this study, a new combined approach based on the application of the Weights of Evidence and the Null-Space Monte Carlo particle back-tracking methods was set up to assess tetrachloroethylene (PCE) contamination due to Point Sources in the densely urbanised north-eastern sector of the Milano FUA (Functional Urban Area). This combined approach offers the advantage of further enhancing the power of each individual technique by integrating both the advective transport mechanism, neglected by the Weights of Evidence, and the influence of specific factors, such as the land use variation, not considered by the Null-Space Monte Carlo particle tracking. To accurately test and explore the performance of this new approach, the analysis was carried out based on the simulation of synthetic PCE plumes using a groundwater numerical model already implemented in a previous study. The Weights of Evidence method revealed that the areas characterised by a groundwater depth lower than 17 m, a groundwater velocity higher than 2.6 × 10−6 m/s, a recharge higher than 0.26 m/y and a significant variation of the industrial activities extent are the most susceptible to groundwater pollution. The Null-Space Monte Carlo particle back-tracking has proved to be effective in delineating the potential source zones and contaminant travel path.The proposed approach can offer additional insights for the protection of groundwater resource. The end-product provides crucial information on the zones that require to be prioritised for investigations and can be easily understood by non-expert decision-makers constituting an advanced tool for enhancing groundwater protection strategies.