ارزیابی نقش شهر اسفنجی به‌عنوان شهری سبز-آبی در ارتقاء سطح خدمات اکوسیستم شهر شیراز

ABSTRACT
Today, with the development of urbanization, the green-blue space in urban areas has received wide attention and has become an important symbol of the health of the urban ecosystem. In this context, it is very important to pay attention to ecosystem services in the planning of the sponge city provided by green-blue infrastructure. In this regard, the current research was conducted with the aim of evaluating the role of the sponge city as a green-blue city in improving the ecosystem services of Shiraz city. The results of the content analysis showed that out of the 35 identified components related to the four most important categories of the green-blue infrastructure ecosystem services of the sponge city by the expert team, after ranking it was determined that the component of sustainable water supply (A1) from the subcategory of production services, the component of effective control of runoff Urbanization and reduction of road flooding (D15) and risk management and flood risk (D3) from the sub-group of regulatory services were ranked first to third with acquired scores of 26.25, 25.55 and 24.78, respectively. Also, in the field of green-blue infrastructure support services of Sponge City, the components of preserving, revitalizing and strengthening vegetation (B4) and restoring natural ecosystems (B3) were ranked tenth and eleventh respectively with scores of 19.77 and 19.63. After social-cultural services, the component of communication and better access to nature (C4) was ranked thirteenth with a score of 19.22
Extended Abstract
Introduction
Economic development, rapid growth of urbanization, and climate change have caused the formation and expansion of gray cities all over the world. The innovative response to these challenges is the development of green-blue cities. In this connection, the sponge city has recently attracted the attention of many urban planners as a plan for a successful green-blue city. The sponge city is based on low-impact development thinking by creating a series of green-blue infrastructures such as green roofs, green walls, gardens, planted strips, permeable canals and ponds, restoration and creation of wetlands, squares, passages, and permeable sidewalks seek to improve the process of absorbing water, storing and reducing the volume of runoff so that cities can hydrological and environmental conditions should be closer before development. In general, taking into account the important role of ecosystem services in the resilience of urban systems, recently, this category has received more serious attention in the world literature, which covers different aspects of urban ecosystem services concerning landscape management, spatial planning, and urban development practices. In this regard, the current research aims to investigate, identify, and prioritize the services of the sponge city ecosystem, which has a green-blue infrastructure. In the case of implementation, it was done in Shiraz as a study area.
 
Methodology
The current research is applied in terms of its purpose and in terms of its nature; it is among the descriptive-analytical studies that were conducted with a mixed method (quantitative and qualitative). Data collection was done using library and survey methods. In the field part, the statistical community of the research consists of experts and professors in the fields of urban planning and management, crisis management, natural resources, and urban environment. The sample size was 30 people and was determined by judgmental and snowball sampling. The theme analysis method was used to analyze the data. In this section, research data was coded and analyzed using MAXQDA software.
 
Results and discussion
The findings showed that among the 35 examined components, the component of sustainable water supply (A1), with an acquired score of 26.25 from the subcategory of production services, has the first rank according to the expert team. The components of effective control of urban runoff and reduction of road flooding (D15) and Risk management and flood risk (D3) were ranked second and third, respectively, with an acquired score of 25.55 and 24.78 from the sub-set of regulatory services. On the other hand, concerning support services, it should be mentioned that the components of preserving, revitalizing, and strengthening vegetation (B4) and restoring natural ecosystems (B3) were ranked tenth and eleventh with scores of 19.77 and 19.63, respectively. Cultural-social services, the component of communication and better access to nature (C4), was ranked thirteenth with a score of 19.22. Due to the fact that in most areas of Shiraz city, residential, commercial, public spaces, etc., have been created using impermeable materials and materials by changing a large part of soft, permeable, and permeable natural surfaces to hard, impermeable, and impermeable artificial surfaces, the ability to absorb water in place has reduced, so it cannot absorb rainwater. Through drainage systems on the way to different water areas, water flows to the streets and sidewalks. This, without control, causes floods and flooding of roads. Therefore, by changing the impervious surfaces in Shiraz city to green-blue spongy infrastructures, the runoff is directed to the subsoil, preventing the flow of rainwater in Shiraz city. Through the proper management of this stored water through the infrastructures, green-blue can become a sustainable water source. Also, green-blue sponge infrastructures can preserve, revive, and strengthen vegetation and thus restore natural ecosystems in the city because, in the sponge city, significant spaces are dedicated to vegetation, green spaces, wetlands, and lake restoration. In it, Importance has been given to the environment, air conditioning, ecosystems, and life cycles of other organisms, which, in addition to maintaining cleanliness, also adds to the beauty and freshness of the city's atmosphere and provides a living environment for all kinds of environmental organisms in the city. In such a situation, the green-blue sponge infrastructure with a nature-oriented approach provides the ground for more communication between humans and nature.
 
Conclusion
In general, most of the urban ecosystem services in the green-blue city can be classified into the improvement of the urban microclimate, the availability of local recreational areas, and the creation of urban habitats. These green-blue infrastructures in the Sponge city can bring positive effects such as increasing the quality of life, improving accommodation and tourism conditions, and improving the well-being of urban residents. So, the effect of green-blue infrastructure on controlling and reducing floods in the Sponge city is clearly seen. Also, the green-blue elements in the sponge city provide more services, such as improving the local climate and providing a space for the recreation of urban residents and urban habitats, so the sponge city should be called a water collector, storer, and donor.
 
Funding
There is no funding support.
 
Authors’ Contribution
All of the authors approved thecontent of the manuscript and agreed on all aspects of the work.
 
Conflict of Interest
Authors declared no conflict of interest.
 
Acknowledgments
This work is part of the doctoral dissertation and was jointly supported by the Department of Geography of Yazd University.