Ying-Yu Hung

The city of Los Angeles acts as a natural flood basin where the surface flows that come from the Santa Monica and San Gabriel mountain ranges travel across the city to reach the Pacific Ocean. This natural system experiences an occasional 100 year flood, where water reaches extreme levels. In 1938, the city experienced the… Read more »

This event was deemed Southern California’s deadliest flood of the 20th century and was the catalyst in channelizing the river systems within Los Angeles County.By 1938, the “wild west” character of Los Angeles was quickly disappearing due to the rapid pace of urbanization. The population in Los Angeles grew rapidly from 1900 to 1930; there were 102,500 residents in 1900, and by 1930, the census counted 1,238,048 residents. In historic photos from this time, supplied by the U.S. Army Corps of Engineers, large river beds make up the landscape, formed by the natural paths of the water. Up to this point, few concrete channels had been built and methods of erosion prevention such as gunite banks, pipe and wire, rock paving and rock mattresses were commonly used to tame the rivers.

During early March of 1938, five days of continuous rain fell on Los Angeles. Erosion controls that were in place could not hold the high level of water coming from the mountains. In downtown Los Angeles, Broadway Avenue became a small lake and truck beds were strapped on top of motorboats to carry workers in and out of the area. The Academy Awards were postponed for a week due to excessive flooding. It was unlike anything the city had experienced before.

In the two decades following the 1938 flood, the concrete channelization of the rivers was a major infrastructure project that altered the ecology and identity of the waterway systems. The transformation, documented by the U.S. Army Corps of Engineers, depicts the phasing of the waterways becoming a single use infrastructure system, which was designed for the sole purpose of discharging stormwater as quickly and safely as possible.

These images show a vast infrastructural and natural water system heavily ingrained within the urban environment. The majority of the time, the channel sits idle, absent of vegetation and a barrier for neighborhoods. Preventive flood measures are necessary yet can there be a more sustainable solution?

In analyzing the potential for multifunctional infrastructures, understanding the natural systems like the flood cycles of the Los Angeles watershed, is an important first step to finding real solutions.

Collapse post

Cancel

Posted by YingYuHung
in Landscape Infrastructure
on 30 July, 2012

Be the first to comment

Share this post
Facebook
Twitter

Urban heat island effect is measured as the temperature difference between the air within the urban canopy layer and that measured in rural areas. Built urban environments can suppress air movements, obstructing cool flows and exacerbating pollution. However, as Alexander Robinson argues in his research for SWA, “high density cities may be our best sustainable… Read more »

FORMATTED Freeway Potential Heat Island Mitigation_001

Borne of the urban condition, urban heat island effect has even more complex impacts, from precipitating the formation of smog (as temperature rises) to creating scenarios that encourage huge consumptions of energy (e.g. air conditioners during a heat island-induced heat wave). This phenomenon is mainly caused by the absorption of solar radiation by urban surfaces, and subsequent trapping of the heat-energy by the geometries of built environments. Mitigating these impacts is just as complex.

Los Angeles is currently posed for worsening heat island effects. Projected temperature rises from global warming will make Los Angeles hotter regardless of heat island effect. With a growing population, the increased development and mineralization of the urban environment seems inevitable. Surface modification, in the form of rooftop greening, has the potential to mitigate heat islands in Los Angeles. The temperature was moderated at one point in history with surface modification: the agricultural irrigation of orchards drastically dropped summer temperatures. The most water-efficient method of surface modification are trees, which produce deep shade and comfortable microclimates.

Facilitated air movement and surface modification are used as urban heat mitigation techniques. The city of Stuttgart in Germany provides an excellent precedent in designing for air movement to mitigate urban heat island effect. The city’s Urban Climatology department has identified areas critical for nocturnal air flows, called “STEP” zones. Cold-air generators (e.g. agricultural fields, forests, oceans) and flow corridors are identified and protected from development, so cool air can flow into the otherwise poorly ventilated city at night. Corridors must be at least 100m wide and kept free of obstructions (including trees).

Many reports provided in Alexander Robinson’s research for SWA recommend wider streets and stepped back buildings to improve air circulation. Depending on urban geometry, freeways have the potential to act as corridors for cool-air movement. Perhaps freeways can be enlisted in moving cool air from the Pacific Ocean through the urban neighborhoods of Los Angeles?

Alexander Robinson was a designer at SWA from 2007-2009. He is currently an Adjunct Assistant Professor in the Masters of Landscape Architecture Program at the University of Southern California.

Collapse post

Cancel

Posted by YingYuHung
in Landscape Infrastructure
on 27 March, 2012

Be the first to comment

Share this post
Facebook
Twitter

With an estimated 1.5 million deer killed annually on US roads , and potentially a greater biomass of smaller animals killed, wildlife crossings reconnect remaining land patches to facilitate healthy metapopulation function (Forman). The emerging science of Road Ecology in the U.S. has studied wildlife connectors, and claims that the combined use of fencing… Read more »

Future of Freeways Wildlife Crossings_001

Although more relevant in less developed areas of California, wildlife crossings provide opportunities for animals to safely cross roadways that otherwise fragment habitats and isolate animal populations. In Southern California, studies show that drainage culverts are regularly used by wildlife (Sandra J. Ng). San Bernardino already has specially designed underpasses for bobcats, coyotes, and deer. An overpass is currently being planned for antelope (California Issues Solicitation for Wildlife Crossing Construction Services).

Once a road has been built, it severs an entire ecological system, disrupting hydrology and established habitats through a variety of effects, including pollution, facilitating invasive plant species movement, dividing and isolating animal populations, changing species composition, and traffic noise (Tanner, Forman). By no means do wildlife crossings mitigate the disturbance a highway has on an ecosystem but they are one step closer in realigning the potential of multifunctional freeways.

.
Forman, Richard T.T. Road Ecology: Science and Soultution. Washington D.C.: Island Press, 2003
Sandra J. Ng, Jim W. Dole, Raymond M. Sauvajot, Seth P.D. Riley, Thomas J. Valone. “Use of Highway Under Crossings by Wildlife in Southern California.” Study. 2001
“California Issues Solicitation for Wildlife Crossing Construction Services.” Targeted News Service, 28 March 2011
Tanner, Dawn Renee. “Road to the Future: Strategies for Wildlife Crossings and youth Empowerment to Improve Wildlife Habitat in Roaded Landscapes.” Dissertation. 2010

Collapse post

Cancel

Posted by YingYuHung
in Landscape Infrastructure
on 20 March, 2012

Be the first to comment

Share this post
Facebook
Twitter

The 48,876 miles of national highways consume 1% of the land in the U.S., which is about the size of South Carolina. This network conceived our sprawling land use habits, extended our commutes and expanded our waistlines. In Los Angeles, the nation’s capital of traffic jams, the average person loses 93 hours yearly sitting in… Read more »

Posted by GerdoAquino and Ying-YuHung
in Landscape Infrastructure
on 19 March, 2012

Be the first to comment

Share this post
Facebook
Twitter

Landscape infrastructure is about seeing old things in new ways – new uses, functions and opportunities for the next generation of our essential systems. This month we look at four landscape infrastructure projects by four different design teams within SWA. Each week, here on the Landscape Infrastructure advocacy page, we’ll post a new project and… Read more »

Posted by GerdoAquino and Ying-YuHung
in Landscape Infrastructure
on 3 February, 2012

Be the first to comment

Share this post
Facebook
Twitter

www.archidose.org is a weekly dose of architecture, which looks at contemporary architectural works with architectural and/or cultural significance. This week, Landscape Infrastructure: Case Studies by SWA was reviewed on the site. “Landscape architecture, planning, and urban design firm SWA was founded in 1957 by Hideo Sasaki and Peter Walker as Sasaki, Walker and Associates. Over… Read more »

Posted by GerdoAquino
in Landscape Infrastructure
on 27 January, 2012

Be the first to comment

Share this post
Facebook
Twitter

Posts Tagged: Ying-Yu Hung

1938 Flood and the Channelization of Los Angeles’ Rivers

Leave a Reply

Freeway Potential: Heat Island Mitigation

Leave a Reply

Future of Freeways: Wildlife Crossings

Leave a Reply

The Future of Freeways

Four Infrastructure Futures for February

Landscape Infrastructure Reviewed on archidose.com