Climate change, rapid urbanization and global warming emphasize the urgent need to expand green areas in cities. According to the World Bank, 56% of the world’s population lives in cities, and this percentage will reach 70-80% by 2050. This means that 7 out of 10 people will live in cities globally. Recent catastrophic floods and climate change have amplified these problems.
Green surfaces contribute to reducing urban temperatures, improving air quality and creating a healthy and livable environment for residents.
According to European Union regulations and World Health Organization recommendations, cities must provide at least 26 square meters of green space per inhabitant. This norm is considered the minimum necessary to ensure a healthy urban environment, but Bucharest and many other cities in Romania are far behind these requirements. Currently, the green area per person in Bucharest is estimated at approximately 9-10 square meters, far below European standards.
This deficiency in big cities has multiple negative consequences: the lack of green spaces contributes to the urban heat island effect, temperatures are considerably higher than in rural or greener areas; air quality is poor due to high carbon dioxide and other pollutants; and limited access to green spaces and opportunities for outdoor recreation affects the mental and physical health of residents.
In order to improve the quality of life of the inhabitants and to meet European standards, large cities must significantly expand the area of green areas in the near future. Achieving the standards will require significant investment and careful urban planning, but the benefits to the health and well-being of residents will fully justify these efforts.
Maintaining these green areas to keep them healthy and aesthetic puts considerable pressure on city administration and available water resources. In Bucharest, watering public green spaces is a significant activity in the management of the urban environment. In the year 2022, Bucharest City Hall reported the use of approximately 2 million cubic meters of water for watering public green spaces, including parks and gardens.
Climate change has a significant impact on the precipitation regime in many regions, which has substantially complicated the management of water resources, especially for irrigation. In today’s conditions, with more frequent extreme weather events, water sources are limited and must be managed very carefully during prolonged drought periods.
This situation is also relevant in the context of urban green spaces, where irrigation requirements can be significant.
In many European cities, the introduction of restrictions on the irrigation of green areas has become a necessary measure to save water. For example, in Spain, Portugal, France and Germany, strict irrigation rules have been implemented to manage water resources during periods of drought.
In the face of these challenges, there is increased pressure on urban planning to find innovative solutions that optimize the green infrastructure of cities. These solutions should not only be efficient in terms of water consumption, but also help reduce environmental impact and support urban biodiversity. By adopting more sustainable water management practices, such as using smart irrigation systems, collecting and using rainwater, and using drought-tolerant plants that require less water, cities can respond more effectively to the challenges of rapid urbanization.
On the other hand, extreme weather variations, such as long periods of drought followed by heavy rains, pose great challenges to urban sewage systems, which struggle to handle the large volume of water in a short time. Built surfaces are not able to absorb or discharge these important amounts of water efficiently, which often leads to the overloading of sewage networks and the loss of water resources.
The expansion of green areas offers a suitable solution to this problem as well, since the surfaces work like natural sponges that can absorb a very large amount of water from intense precipitation. Thus, green infrastructure can facilitate the proper functioning of urban sewage systems.
In this context, urban landscaping can no longer have only a decorative role; green areas bring numerous benefits in creating a more pleasant and healthy urban environment. They contribute significantly to reducing urban temperatures through evapotranspiration, clean the air of carbon dioxide and other harmful substances, produce oxygen, provide thermal and sound insulation, contribute greatly to rainwater management and create a more aesthetic and friendly image of the urban environment.
Landscaping projects must therefore focus not only on the aesthetics of the landscape, but also on solving ecological problems, ensuring sustainability and biodiversity, and maximizing the benefits they can bring to the urban ecosystem. Dwindling water resources and climate change require economical water management, with increasingly frequent bans on irrigation in urban green areas, which encourages society to find solutions that provide maximum results with minimum investment in green infrastructure.
The maintenance of grass surfaces is extremely water-intensive, especially during periods of drought, when they require a large amount of water to remain healthy. Even with modern irrigation systems, the high frequency of lawn watering demands a significant consumption of water resources. The lawn watering rate per 1 m2 is regulated by SNiP (Technical-Sanitary Norms and Rules). This consumption is approximately 15-20 liters per square meter of plot. This rate is optimal for a watering frequency of once or twice a week. If there is a tendency to compact the soil base, then the consumption increases to 25 liters per square meter. In addition, lawn maintenance, including frequent mowing, weed control, and fertilizer application, also consumes significant economic and energy resources.
To save the use of resources, it is recommended that urban greening schemes use plants that require a minimum level of maintenance and are able to thrive in drought conditions, where the functions of green spaces allow this (eg. decorative green surfaces, without daily trampling).
A major advantage of Sedum is that it can be maintained without irrigation and contributes significantly to saving water resources in the urban environment. The plants can survive the hot summer months without irrigation, changing colors to shades of red during dry spells towards the end of the summer season, returning to green with the arrival of autumn rains. The Sedum carpet thus offers a sustainable and resource-efficient solution for expanding green areas in the urban environment.
In the case of greening tram lines, a structure similar to that used for green roofs can be applied, with layers composed of special materials with increased water retention capacity, thus ensuring the necessary moisture for plants. These solutions contribute to the efficient use of rainwater, reduce the load on urban sewage networks and at the same time improve the aesthetic appearance of the urban environment. Green tram lines and railways contribute to a more natural and harmonious urban landscape, adding a touch of life to the built environment.
A similar sustainable solution is the use of drought-tolerant shrubs and perennials that can be used as ground cover, such as rosemary, cotoneaster, or biodiverse wildflower plantings with varied indigenous perennial species that can provide healthy green surfaces and low-maintenance aesthetics, no watering or trimming.
Several cities around the world have successfully integrated drought-tolerant plants into their urban landscapes, such as:
- Vienna: The city has implemented green roof projects using Sedum and other drought-tolerant plants to enhance water retention and reduce urban heat islands.
- San Diego: This city uses a comprehensive approach to stormwater management, incorporating drought-tolerant plants to manage runoff and improve water quality.
- Singapore: Known for its innovative water management practices, Singapore has developed advanced technologies for water recycling and efficient irrigation, integrating drought-tolerant plants into its urban planning.
The key to the sustainability of green areas in the urban environment lies in the use of drought-resistant plants, the intelligent management of water resources and the integration of modern landscaping solutions. The use of Sedum plants and other drought-resistant plants allows the creation of sustainable green areas in cities, reducing water consumption and contributing to the health of the urban ecosystem. Such areas not only improve the appearance of cities, but also make them more pleasant and livable, effectively adapting to climate change and increasingly limited water resources.
Image source:
Freepik.com
Urban ecosystem services – C/O City (cocity.se)
Why Do Urban Forests Matter? (thecityfixlearn.org)
How Heat Island Effect is Impacting Urban Cities: Building a Smart Grid (envirobond.com)
Washington Floods Expose a Double Threat: Old Drains and Climate Change – The New York Times (nytimes.com)
