Technical note: Graph theory-based heuristics to aid in the implementation of optimized drinking water network sectorization

Drinking water distribution networks form an essential part of modern-day critical infrastructure. Sectorizing a network into district metered areas is a key technique for pressure management and water loss reduction. Sectorizing an existing network from scratch is, however, an exceedingly complex design task that designs in a well-studied general mathematical problem. Numerical optimization techniques such as evolutionary algorithms can be used to search for near-optimal solutions to such problems, but doing so within a reasonable timeframe remains an ongoing challenge. In this work, we introduce two heuristic tricks that use information of the network structure and information of the operational requirements of the drinking water distribution network to modify the basic evolutionary algorithm used to solve the general problem. These techniques not only reduce the time required to find good solutions, but also ensure that these solutions better match the requirements of drinking water practice. Both techniques were demonstrated by applying them in the sectorization of the actual distribution network of a large city.

Residential Mobility of a Cohort of Homeless People in Times of Crisis: COVID-19 Pandemic in an European Metropolis

Most vulnerable individuals are particularly affected by the COVID-19 pandemic. This study takes place in a large city in France. The aim of this study is to describe the mobility of the homeless population at the begin-ning of the health crisis and to analyze its impact in terms of COVID-19 prevalence. From June to August 2020 and September to December 2020, 1272 homeless people were invited to be tested for SARS-CoV-2 antibodies and virus in and completed questionnaires. Our data show that homeless populations are sociologically dif-ferent depending on where they live. We show that people living on the street were most likely to be relocated to emergency shelters than other inhabitants. Some neighborhoods are points of attraction for homeless peo-ple in the city while others emptied during the health crisis, which had consequences for virus circulation. People with a greater number of different dwellings reported became more infected. This first study of the mo-bility and epidemiology of homeless people in time of pandemic provides unique information about mobility mapping, sociological factors of this mobility, mobility at different scales and epidemiological consequences. We suggest that homeless policies need to be radically transformed since actual model exposes people to infection in emergency.

Opportunities for development of elevated electric transport in a large city

Modern large cities include both historically developed central parts and rapidly developing peripheral neighborhoods. Today, transport flows are formed not only by traditional bus, trolleybus, and tram routes, but also by significant fleets of taxis and private vehicles. An increase in traffic load and a shortage of parking spaces significantly reduces the capacity of roads and negatively affects the environmental situation. Ensuring transport accessibility based on the development of underground urban transport, the metro, is accompanied by great labor intensity, time and financial costs. Residents of large cities try to use bicycles, electric scooters, monowheels for intra-city movements. However, in winter in Russia this type of ecological personal transport becomes less accessible. A promising option for the development of public transport for large cities with a significant length of the street network in the absence of the technical possibility of expanding the roadway, can be an elevated electric transport (monorail). Using the example of the city of Samara, where the level of automobilization in 2019 reached 344 cars per 1000 people, the possibilities of developing the transport system of a large city with the inclusion of a monorail transport section in such a system are considered. This innovative solution will improve transport accessibility and reduce the negative impact on the urban environment. The average payback period of the project will be 4.4 years.

GEOGRAPHICAL ANALYSIS OF THE ROAD TRAFFIC AND PARKING SPACE IN A LARGE CITY (ON THE EXAMPLE OF IZHEVSK)

One of the most important components of the territorial socio-economic complex of a city (especially a large one) is the system of urban passenger transport, which, in turn, consists of two subsystems: urban public transport and personal vehicles. In 2000-2020. many large and medium-sized cities in Russia are going through a period of active motorization. Izhevsk is no exception in this regard. The level of motorization of the population has been increasing in recent years both in the city and in the Udmurt Republic as a whole. There is a growing need to reduce the flow of personal vehicles towards more active use of public transport. Urban public transport (for all its significant scale) has, as a rule, 2-3 owners and therefore is largely manageable, which cannot be said about personal vehicles. It is not possible to force car owners to switch to public transport by order. But it is possible to create such conditions when the resident himself does not use his own car, but gives preference to public transport. For example, to organize the work of a single parking space, in which the placement of paid parking lots will make it unprofitable to visit many of the most attractive objects (especially in the central part of the city) by private vehicle. An example of such relevant work is shown in the proposed article. By order of the Administration of Izhevsk, the authors of the article have identified the most optimal locations for paid car parks. The choice was determined based on the results of step-by-step work to assess: the location of the potential of Izhevsk public transport, the intensity of traffic flows, the density of the population, the availability of existing parking areas, points of attraction for vehicles.

Investigating commercial and convenience services installed in intermodal passenger terminals located in mid-sized European cities

The concept of intermodality has gained key importance in the sustainable mobility strategy of the European Union. In the past two decades, different types of intermodal passenger terminals (IPTs) have been built in many European cities. These facilities provide possibility for passengers to change transportation mode or route in a short time and connect long-distance transportation services with public transportation modes under one roof. IPTs, however, are more than just hubs in the transportation network, but, due to their size and special location in the city, they are landmarks of cities. In addition, IPTs host not only transportation services but also different types of commercial and convenience services used both by passengers and local people. This study focuses on classifying IPTs based on their hierarchical position in the transportation network and determining which type is the most generally located in European mid-sized cities. Then, an investigation is carried out to map those commercial and convenience services that are the most installed in such IPT types. Finally, three European IPTs located in mid-sized cities and one in a large city are analysed to reveal the similarities and differences in the commercial and convenience services they host. This study found that such commercial and convenience services are most suitable for installation in IPTs that are related to transportation services, do not require a substantial amount of space, and do not block or obstruct the movement of people. Furthermore, as a component of the comprehensive planning documentation, a preliminary commercial feasibility study should be produced for each IPT.

FPV for Sustainable Electricity Generation in a Large European City

There is a huge interest worldwide related to continuously increasing the use of renewable energy sources (RES) for electricity generation. Romania, at this moment, even though it has to attain a share of 30.7% of RES from total energy consumption by 2030, does not have any major investment project of this kind in the near future. Photovoltaic (PV) is one of the most promising technologies, with decreasing prices for PV panels but with the disadvantage of large, needed surfaces. This study presents a solution to install PV panels where there is a need for electricity, in a large city, by using the surface of a reservoir. “Lacul Morii” Reservoir in Bucharest is the choice for the case study. The insolation and the possibility to install floating PV, as well as electricity generation, benefits for water quality and carbon dioxide (CO2) emissions reduction are assessed, and even the installation of charging stations for electric bikes and cars. The results are very promising, and the main conclusion is that, after its realization, the floating photovoltaic (FPV) plant on “Lacul Morii” Reservoir will be a source of clean electricity and a demonstration project on how to benefit from solar energy to produce electricity in large cities where there are reservoirs.

Prospects for the Use of Mobile Operator Data in Studies of Natural and Man-Made Risk

The article proposes a conceptual substantiation of the possibility of using the cellular operators data in order to assess the population vulnerability in the natural risk studies. Cellular operators data allow obtaining information on the differentiation of the population vulnerability in a large city (the article provides the case of Moscow) to natural and manmade hazards, taking into account the actual population size and its movement within different time cycles (daily, weekly, seasonal). A reliable information of how many people are at each point of the urban space at a certain point in time will allow not only to timely assess the most likely number of people in the potential danger area, thereby simplifying the work of specialized emergencies services, but also to competently develop a set of preventive measures in accordance with the real need.

Finger Ring Amulets with the Image of the Holy Rider of the 7th Century from the Crimea

Introduction. The group of jewelry with Christian symbols that existed in the Crimea in the early Middle Ages includes cast bronze rings, on a flat shield of which the image of a holy rider with a cross in his hands is engraved. The rings were found in the South-West Crimea in the burial grounds near the village of Luchistoe, Skalistoe and EskiKermen, as well as in Kerch at the early medieval necropolis of the Bosporus, in the burials of the 7th century. Methods. For the attribution of published products, a circle of analogies is identified, findings from the territory of the Eastern Roman Empire are analyzed. The iconography of the holy rider is compared on various subjects. In the Crimea, three of the published finger rings were found in in situ burials, as part of a closed complex, together with tools with a narrow dating, which makes it possible to clarify the time of existence of this type of products in the region and to determine the method of wearing it. Analysis. The plot depicted on the finger rings has an undeniable resemblance to the scene of the solemn entry of Jesus Christ into Jerusalem, described in all four Gospels and well known from the numerous pictorial monuments of the early medieval period. The iconography of that scene originated in the era of Constantine the Great, under the influence of imperial art and in many ways corresponded to the Triumphal entry of the emperor to Rome or any large city of the empire. The image of Christ the rider on the Crimean finger rings belongs to the iconographic type, which became widespread in the 6th–7th centuries, mainly in Egypt, the Syro-Palestinian region and Asia Minor. The quality of execution of the published rings from the Crimea allows us to speak about their local production. Byzantine products that came to the peninsula thanks to stable trade relations with the empire or were brought by pilgrims from holy places served as models for the Crimean artisans. In the minds of ancient Christians, the image of Christ the rider had a powerful protective power. Placed on the shield of the ring, it endowed the decoration with the properties of an amulet, protecting the person wearing it from all troubles. The rings originating from Crimea belonged to a teenage girl and young women who wore them on their hands – on the right index or ring finger, or in special belt bags, in which, in addition to utilitarian items, various amulets were also put. Results. The study of rings makes it possible not only to expand knowledge about jewelry that existed in the early medieval times, but also to replenish our information about the daily life of the Christian population of the early medieval Crimea.

Space Redevelopment of Old Landfill Located in the Zone between Urban and Protected Areas: Case Study

Landfills are elements of the waste management system, without possibility of further reclaiming, according to the requirements of a closed-loop economy, but with the possibility of transforming the area into other functions. The research combined monitoring of plant species, suggesting the composition of vegetation cover for pro-ecological management, analysis of functional and infrastructural incorporation of the landfill in the surrounding landscape, and proposals for reclamation and social application. An assessment of geotechnical safety was also made. Modernization of the landfill suggests that the pressure placed on other untouched locations should decrease. The designed space allows reintroducing socio-ecological life into this degraded area. Taking advantage of the character of the area, including variable development and significant landscape potential on the outskirts of a large city in the vicinity of protected areas, there is the possibility of creating new spatial quality following the standards of modern architecture-urban planning. One of the innovative elements of the project is the implementation of energy from renewable sources, including landfill biogas, photovoltaic panels and heat pumps. The development design includes social expectations and adaptation of new techniques to functioning in times of increased sanitary threats. The proposed design direction may be considered as a recommended trend for the sustainable development of urban areas.