City and Environment Interactions最新文献

Although flush toilets and sewerage are usually considered the height of comfort in 21st-century urban societies and the technical and sanitary culmination of human excreta management, they are increasingly being challenged for their environmental footprint and financial cost. Alternative management methods, broadly termed “source separation”, are being developed to address these issues. However, the widely shared belief in the absolute superiority of sewerage for public health is hindering the development of such systems. In this paper, we briefly re-examine the contribution to public health of sewerage as a means of managing human feces, in both its historical development and current implementation. We suggest that management of feces by sewerage is just one element among others in a systemic change, that it usually occurred much later than the others, and that the epidemiological transition usually attributed to sewerage only was, as a matter of fact, strongly supported by associated improvements in drinking water, health care, hygiene practices and good nutrition. We show that risk control in sewered cities is not based on a barrier between human feces and the environment (what we might call sanitation), but on barriers between a contaminated environment and the different uses of water. We call for a more comprehensive analysis of the effects of sewerage on public health, in present times and historically, not only at the scale of a city but at the broader scale of all impacted communities. We also call for a comparison of these effects with those of other sanitation systems that have much lower environmental footprint.

The world’s population is estimated to reach 11 billion in this century, with some 8.5 billion living in urban areas. Cities become unprecedented hot spots of demand for virgin water and food, as well as producers of large volumes of valuable waste. The recycling of urban nutrient-rich liquid and solid waste as fertilizer in agriculture will thus be of benefit to both sectors. The analysis suggests that recycling has the potential to become the ultimate sink for organic waste and wastewater, while simultaneously securing the supply of food and fertilizers, and reducing both local and global environmental impacts. Presently, harmful chemical substances from various consumer products in our chemical society are disposed of in urban waste flows and hamper recovery and reuse. A combination of counter measures such as not mixing nutrient-rich blackwater with grey water polluted with chemical compounds, are crucial. The sludge from the small volume of blackwater can contribute enough fertilizers to secure global food supplies by the year 2100. The voluminous grey water will contain few pathogenic microorganisms and can be treated for non-potable reuse. Three urban arrangements are analysed: Singapore (entire city), Helsingborg in Sweden (city district), and Bangalore in India (eco-house).

Urban Flooding represents a significant problem in developing urban areas caused by inadequate stormwater drainage systems, increased impervious surface areas, and climate change. The performance of drainage systems can be evaluated using simulation models such as the stormwater management simulation model (SWMM). In this study, the potential impacts of future design rainfall on the performance of stormwater management systems were assessed by altering a hyetograph derived from rainfall intensity duration curves from three climate models. In addition, the effects of continued urbanization on the systems have been simulated by changing the percentage of imperviousness from current land use conditions. According to the findings, existing drainage systems cannot manage the expected flooding risks caused by a slight change in future rainfall intensity under each climate model. As a result of urban development, increasing the imperviousness ratio from 10% to 70% has increased peak runoff from 51.3 to 82.4 m³/s, flooding volume amplified from 24,320.5 x10³ to 33,647.4 x10³ m³ (representing 38.4% of the increase), and flooded nodes risen from 64 to 196 (representing 67.12% of raise). Overall, flooding locations and magnitude were identified, while drainage systems failed to safely convey surface runoff at baseline conditions, implying that future flooding will be more intense. As a result, selected mitigation strategies should be considered to alleviate the flooding risks that disrupt the socio-economic environment and the resulting significant property and life losses in Dodola, Ethiopia.

This paper investigates the use of a citizen science approach for air quality monitoring to explore the likely pollution impacts of the new Missing Link #12 road passing through the informal settlement of Kibera, within Nairobi. Citizen science approaches are gaining relevance in air quality monitoring thanks to the advancement in environmental monitoring technology and the opportunities created for community-based organizations to collect data on air pollution through low-cost sensors. Fourteen households located in proximity to the Missing Link#12 were equipped with optical particle sensors. Data collected indicated that people living along the road are exposed to levels of PM_2.5 and PM₁₀ above WHO recommendations, mainly due to the particulate generated by the construction site and fuels used for indoor cooking. A community engagement workshop revealed that participatory approaches are useful for improving awareness of air pollution and associated health implications. It also allowed the community to enhance their capability to gain and use scientific tools to address local issues, and potentially lobby decision-makers to solve them. In the context of transport infrastructure development in African cities, such an approach can be a means of collecting data and monitoring the impacts of air pollution during and after road building.

Perched on the edge and corner of the city center, pocket parks transform urban vacant land into vibrant urban oases. It can greatly shorten the distance from citizens to the park, thereby promoting citizens' participation in outdoor activities and improving urban vitality. The construction of pocket parks in China started late. However, it has developed rapidly in recent years, which supports urban regeneration. A government document, published by the Ministry of Housing and Urban-Rural Development of the People’s Republic of China in 2002, promotes the construction of pocket parks. In the process of promoting the construction of pocket parks in Chinese cities, problems such as unclear construction standards, difficult operation and maintenance, blind copying, and emphasis on the landscape over the function have emerged. The aforementioned issues are elaborated and corresponding suggestions are pointed out in this short communication.

Urban sustainability is the goal of many cities in the world, yet very few have achieved a level of sustainability that goes beyond the most basic environmental objectives. The practice and assessment of sustainability implementation are greatly compounded by lack of funding, technical know-how, political will, and the power disparity between dominant institutions and marginalized communities. This systematic analysis of urban sustainability literature involved the review of 241 studies published between 2010 and 2022. We critically examined current debates and challenges in urban sustainability, identifying gaps and opportunities and providing recommendations for creating equitable, just, and sustainable urban futures. We also reviewed 23 studies to summarize the social, ecological, and technological systems (SETS) indicators used to measure urban sustainability in the same period, many of which may not be relevant to the lived experiences of marginalized communities. To move toward more meaningful and equitable pathways, it is important to develop SETS indicators of urban sustainability that are reflective of the experiences and priorities of diverse groups in society. This review identifies four major issues in the current urban sustainability literature: space, scale, stakeholders, and dimension. These issues need to be centered in sustainability planning in order to develop solutions that are appropriate for the local context.

The viability of wildlife populations in cities is strongly associated to the qualities of urban open spaces and development patterns. Open space systems can serve as armatures to address adverse effects of urbanization on biodiversity. Landscape planners and designers use spatial concepts to translate principles of landscape ecology into working diagrams of land use and land cover to anticipate ecological effects. This paper investigates the consequences of adopting different open space spatial concepts (corridors, patches, and network) in combination with development patterns (compact and dispersed), simulated in eight alternative future scenarios with computer model Envision. Two approaches were used to quantify the effects of the different spatial concepts and urban patterns on Red-legged frog (RLF), Western meadowlark (WML), and Douglas squirrel (DSQ) habitats and populations in an area of urban expansion. First, the amount of habitats was assessed for the initial landscape (ca. 2010) and for the eight future scenarios (year 2060). Second, using the Individual-Based Model (IBM) HexSim, populations of the three species were quantified. All scenarios had increased sums of habitat area, but results showed that differences in open space spatial concepts played a greater role in determining population sizes and were more influential than different development patterns. Network scenarios presented more habitats and the largest populations of RLF. Park and network scenarios showed the most habitats and populations for the WML. No open space and greenway scenarios did not have enough habitats for the WML, but presented the best results for the DSQ. Populations in compact development scenarios showed a small advantage over most dispersed development scenarios. However, in park and network scenarios, dispersed development showed a large influence in the increase of WML population. The study shows that the adopted framework is useful to predict the consequences of landscape plans on wildlife species populations, evaluate trade-offs, and inform planning decisions.

Extreme phenomena have emerged strongly in urban areas in recent years and are directly linked to the current urban challenges, such as climate change and digital transformation, that future cities must face efficiently. Risk management in urban public spaces is the primary means by which decision makers and local stakeholders ensure urban resilience and enhance urban smartness. In this framework, the current research proposes risk management solutions for urban areas considering their complexity as systems. The implementation of STPA (System-Theoretic Process Analysis) method, as a relatively new hazard analysis technique for complex systems is presented. The applied method delivers a mechanism useful in understanding where gaps in current operational risk structures may exist. The findings in terms of loss scenarios can be used to generate a variety of safeguards to ensure secure operational control and in implementing targeted strategies through standard approaches of risk assessment. Results from a use case in Patras city, Greece, indicate that a systemic, hierarchically structured, and adaptive approach, can effectively assist local stakeholders in risk management of urban public spaces.

Improving environmental quality to promote outdoor activities, which also aims at providing social benefits, is an extensively researched field of study. In this study, a sustainable urban solution is evaluated as a prototype using the physiological equivalent temperature (PET) index. The literature demonstrated the local deficit of increasing social qualities through the development of a prototype that performs as a mitigation strategy to improve the urban thermal environment. To fill this gap, the aim of this experimental study is to create a neutral outdoor thermal comfort area that is suitable for social gatherings while minimizing local heat stress. We investigated six selected sites using ENVI-met 4.4 software, and we validated them with the observed data by two types of validation metrics. The sites were located near the Tigris River in Baghdad. The conditions at the sites were analyzed between 8:00 and 24:00. The simulation findings revealed the possibility of achieving thermal comfort during most of the working hours. A reduction in thermal stress by ∼18.4 °C was observed with a drop of 36.4% of PET results. The urban solution contributed to a decrease in the temperature by four degrees from the existing situation, which promotes a sustainable outdoor urban area. In hot climates, any outdoor activity between 12:00–16:00 is generally discouraged, whereas (8:00–10:00 & 18:00–00:00) hours are suitable for social interaction. However, multistoried buildings with sufficient orientation and shading could be ideal for achieving local sustainability, whereas the river's presence and its low albedo significantly raise the mean radiant temperature (MRT) by ∼7–8 °C, which proves its importance in heat reduction. The hybrid fabric altered the traditional courtyard's climatic characteristics, exacerbating its heat stress. The largest dip in PET in the courtyard area occurred at 17:00, with a drop of 13.6 °C, which was smaller than the rest of the areas. The additional sustainable prototype had a significant impact on influencing the microclimate and played a decisive role in determining thermal comfort. The prototype's high- albedo materials and dense, selective local trees have a direct effect on reducing the local air temperature and MRT. This, together with the physical characteristics of the surrounding area, helped to minimize PET outcomes and improve the local thermal environment. The findings of this study serve urban designers by verifying the success of the modelled design prototype spatially and environmentally.