1.Project Statement
Riyadh, the capital of Saudi Arabia, is one of the fast growing cities in the world, with a population over 7.2 million. Green space is in terrible demand. In 2019, the Riyadh Development Authority (RDA) announced the King Salman Park (KSP) project converting the former King Salman Airbase in the center of the city into a mega park, 13.4 square kilometers (5 square miles) total and 4 times the size of New York’s Central Park, making it the largest urban park in the world. KSP comprises 9.2 square kilometers (3.6 square miles) of green space and the rest area will be developed as Art, Culture, Market, Conference, Entertainment and Sports hubs, etc. The Park is encircled by a giant Innovation Loop of 7.5 km (4.35 Miles), and is connected to the city by 5 Metro & 10 Bus Stops, and is expected to be used by 400,000 visitors daily. As part of this grand vision, the project presented here is a landscape concept proposal for the 9.2 square kilometers green space including that within the loop and the green figures extending into the urban fabric.
This is about the philosophy and approaches to make the world’s largest urban park in a harsh climate. Deeply rooted in its native land and culture, King Salman Park is an invented oasis. In fractal forms, the landscape is composed of Wadis, Dunes and Gardens parametrically carved in an extensive Carpet weaved by various native plants. By cut-and-fill, a spectrum of habitats of various microclimates are created for diverse types of vegetation and people places. An irrigation system is created to recycle the city’s waste water and is also biologically cleansed for public use. The invented Oasis is a memory of the past celebrating the magic land carved by wind and water, and the ancient wisdom and arts of survival. It is also a prophecy of the world’s sustainable future showcasing solutions for mankind to remain prosperous on this planet through a designed ecosystem that provides sufficient ecosystem services for this generation and those to follow.
2.Objective and Challenge
To invent such an urban oasis, following major challenges have to be addressed:
(1) Climate: Riyadh has a arid hot climate with annual mean temperature 25.7 degrees Celsius (78.2 degrees Fahrenheit). How to create comfortable outdoor space?
(2)Water: In Riyadh, the total annual precipitation averages only 101.3 mm (4 inches), and evaporation reaches 1971mm (77.6inches) annually. Meanwhile,the city is increasingly suffering strong floods, which have caused substantial property damage and people got drown; There is rich groundwater, but heavily contaminated. The city has annual available treated waste water about 200 cubic meter per capita, the amount of usable grey water is substantial.
(3)Vegetation: The dry and poor soil is a huge challenge for cultivating a lush and rich vegetation.
(4)Scale: The size of the Park and the flatness make it challenging to create human-scale spaces with intimacy and richness.
3.Design Strategy
In order to find solutions to address the above challenges, the following approaches are taken:
(1) Memory: Design to be inspired by the nature and cultural heritages of Saudi for the adaptive solutions to address the multiple challenges that makes KSP unique and local. Wind and water are two major forces that have been carving the landscape of Saudi, such as the Wadi, the dunes and the desert vegetation. The traditional wisdoms of agriculture, architecture and gardening as well as the traditional Arabic and Islamic arts are rich resources of inspirations for design.
(2) Prophecy: KSP shall be a showcase of the world’s sustainable future, including sustainable construction, sustainable and productive use of water and materials and energy, sustainable cultural identity with contemporary design.
(3) KSP shall provide ecosystems services to fulfill the needs of citizens, including regulating climate for the city and people, producing cleaning water and food; supporting native biodiversity; providing cultural, educational and spiritual services.
Following above design philosophy and approaches, the oasis is to be built in five systems:.
(1) Terrain: Fractal Design of wadi, carpet field and dunes
Wadi: A fractal land forms of wadi are made by simple cut-and-fill on sit. It radiates from the center of the Park and stretches along the Green Fingers deep into the city to open up connections between parks and city, collects storm water and make easy accesses for the residents. The wadi is a cool escape.
Carpet fields: The limestone materials carved from the ground will be sieved into different grain sizes and colors to create a Carpet of gravels in a designed pattern, which functions as mulch to keep soil moisture.
The dunes: Upon the gravel Carpet, dunes of various sizes are created by cut-and-fill responding to the movement of wind to avoid the hot waves from the north and catch the cool waves within the sunken spaces encircled by the dunes. Various microclimates are created.
(2) Water
Three systems are designed to address the multifaceted challenges of water: Using the radiating Wadi, urban stormwater is collected and filtrated to nurture wetlands; The pretreated domestic waste water will be cleansed through constructed wetlands in each of the green fingers before flowing into creeks and converges to the central lake; Using the recycled waste water, an irrigation system is designed, with an aqueduct installed above the Grand Green Corridor along the innovation loop that distributes water throughout the park using gravity.
(3) Vegetation
Various types of vegetation are designed according to different habitats, including wetland in the Wadi, the perennials over the Carpet Field, shrubs over the Dunes, Gardens in the Dunes with various themes such as orchard garden, herb garden, aroma garden, etc. Acacia trees of various kinds are planted along the pedestrian system and activity places to provide shade. The diversity of Acacia species native to this region make possible to differentiate individual zones with unique flower colors.
(4) Connections and Structures
Circulation:Through the Grand Green Corridor, the green spaces are accessible by connecting the entrances with multiple Metro and BRT stations, city bicycle network and AV (autonomous vehicles) system. The circulation system in the park comprises a network of pedestrian paths, service roads and connections of various kinds.
Grand Green Corridor:Inspired by Islamic arch and aqueduct, the contemporary Grand Green Corridor is designed as a multifunctional device which combines shading, vertical gardens, aqueduct and solar energy panels all together. It is constructed with limestone excavated from wadit. Water for irrigation is released at the top of the corridor where it slowly trickles out of the stones to allow mosses and ferns to grow and create a green wall that turns the corridor into a cool escape for residents.
Diamond Skywalk:In the center of the KSP, a skywalk is designed to provide connections across the Wadi, a viewing platform.
(5) People places
Gardens, places and facilities are programed for various activities. The activity places in the green space are integrated with the urban clusters and the eight development hubs.
4.Conclusion
The vision that “KSP will be a global icon, a unique location that raises the standards for parks, while catering to the needs for Riyadh citizens”(HRH Prince Mohammed Bin Salman Al-Saud Ambition for KSP – JULY 2018) will be made true, because KSP is a memory of Saudi’s past, with deep understanding of the cultural and natural heritages, and the revival of ancient wisdom; It is a prophecy of the world’s sustainable future in that it demonstrates the sustainable practice, and achieve sustainable cultural identity with contemporary design. KSP provides people with various ecosystem services in deadly demand.