Smart and green cities

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DR. WILLIAM DAR

In a forum within the 2017 science awards ceremonies jointly sponsored by the Bank of Philippine Islands Foundation and the Department of Science and Technology where the audience were college students and scholars, I encouraged the audience to take up science and technology courses and conduct research for development including those related to agriculture, to help build resilient cities that are “smart and green” in the face of climate change.

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At the beginning I highlighted the critical importance of the agriculture sector to the economy of the country contributing 11 percent to GDP, employing 30 percent of labor force, ensuring food and nutritional security, and reducing poverty.

I started off my discussion on resilient cities with urban agriculture as an important endeavor, which is increasingly becoming popular as a “greening” strategy in urban areas.

So far, urban agriculture has yet to take root, literally, in many urban areas in the Philippines – just look at the many vacant spaces in Metro Manila and elsewhere where urban agriculture is very feasible. The empty rooftops of many high-rise or even low-rise buildings can also be utilized for urban agriculture.

Urban agriculture is not only limited to growing crops, primarily vegetables: it also includes the growing of trees, and raising of animals and fish. It could also be integrated into the urban economic and ecological system of an urban area.

While there are programs to promote urban agriculture, policies should be put into place for the development of safe and sustainable urban agriculture that takes into account the following: formal acceptance of urban agriculture as an urban land use; enhancing access to vacant open urban spaces and the security of agricultural land use; enhancing the productivity and economic viability of urban agriculture by improving access of urban farmers to training, technical advice and credit; supporting the establishment and strengthening of urban farmer organizations; and taking measures that prevent/reduce health and environmental risks associated with urban agriculture.

Organic farming should also be encouraged in urban areas; the advantage of organic products is it can demand up to a 200-percent premium price over traditionally grown farm products, which makes it a very good business proposition especially when farming in the city is undertaken in a very limited area like rooftops of buildings.
And while organic agriculture cannot feed the world, it can help lessen hunger.

Gardening in schools, however, is the most viable approach to urban agriculture to produce larger quantities of
crops since many schools (at least in Metro Manila) still have a lots of green spaces where traditional planting can be undertaken; and vacant spaces where growing in containers could be viable.

Educationally, school gardening also aims to increase the relevance and quality of education through experiential learning activities in food production and nutrition; Nutritionally, it can improve food diversity and availability to meet nutrient deficiencies and enhance the prospects of community food security; Economically, it can reduce food expenses, create savings, provide an alternative income source for families to address poverty in a long-term basis.

And of course, school gardening from an ecological standpoint can sustain and enhance the ecosystem and environment of a city.

But if open space is limited in a city, vertical farming is a very viable strategy or method that uses vertically stacked layers, such as in a skyscraper, used warehouse or shipping container. This saves space, assures year-round crop production that can be increased, and protection from weather-related problems like floods. Vertical farming can also be made part of water conservation and recycling programs or projects.

Aquaponics, or combining aquaculture and hydroponics, is also a very good approach to urban farming. In aquaponics, fish is raised in tubs or chambers so their excretion can be utilized as bio-nutrients for plants; while the plants raised clean the water, creating a perfect environment for the fish to grow. Aquaponics is actually perfect for the urban setting because two products are produced: crops and fish. Also, organic food can be produced through aquaponics that is actually a cleaner form of gardening and is not a complex set up.

Meanwhile, urban forest parks, while not aimed at food production, can be established in open spaces and schools. Besides improving air quality, urban forest parks can create employment through ecotourism, and help sustain biodiversity by providing habitats for animals like birds. The trees in urban forests can also manage water runoff that helps check soil erosion, and encourages people to improve their well being by communing with nature or exercising.

Urban waste management should also be a major strategy for resilient and sustainable cities, and an integral part of urban farming.

Biodegrable wastes like food scraps are very good raw materials for the production of compost or even vermicompost if vermicomposting facilities are established.

Also, utilizing biodegradable food wastes to produce natural fertilizer will decrease foul smells in garbage bins in the city.

Eventually, the segregation of biodegradable wastes from solid wastes that can be recycled will reduce the pressure on landfills, where only “residual” wastes should be dumped.

Also, there would a significant reduction in green house gas emissions from garbage because food scraps are a source of methane emissions from landfills.

The surface and ground water are also protected because leachates or liquid from biodegradable wastes are eliminated or minimized with segregation. Landfills, if these do not have proper leachate processing systems that are very expensive and are dumped with biodegradable wastes, can discharge large amounts of contaminated liquid that pollute aquifers, rivers and streams.

But even if cities can be assured of clean water supply by large water companies like Maynilad and Manila Water, strategies like rain water catchment (RWC) and wastewater management should be integrated in the planning, programs and projects of green and smart cities.

As much as possible, every home and building in the city should have an RWC system to save run-off water to meet demand shortages during the dry season, to recharge aquifers and groundwater storage, reduce soil erosion and downstream flooding, prevent land subsidence, minimize damage from El Niño and La Niña damage, reverse salt-water intrusion, and flush out chemical leaching.

Meanwhile, wastewater management is aimed at removing organic and inorganic matter which causes water pollution, and remove pathogenic organisms to protect the environment and human health. The end product of waste water management is recycled water that can be used for the following: washing cars; landscape maintenance; golf course irrigation; cooling water for power plants; toilet flushing; dust control; and construction activities like concrete mixing.

There are many advantages of having a well-planned smart and green city taking into account what I had just discussed.

Water quality protection measures help promote proper landscaping that reduces nitrate leaching from the soil into the water supply. Also, surface water runoff is reduced, keeping pollutants out of waterways and preventing septic system overload.

Trees in a parking lot can also reduce on-site heat buildup, decrease runoff and enhance cooling at night.

A dense cover of plants and mulch holds soil in place, keeping sediments out of lakes, streams, storm drains and roads; and reducing flooding, mudslides and dust storms. Eventually, there is reduced soil erosion.

Trees, shrubs and turf remove smoke, dust and other air pollutants from the air. In fact, one tree can remove 26 pounds of carbon dioxide from the atmosphere annually, equaling 11,000 miles or 17,600 kilometers of car emissions.

Trees also modify temperatures, so the amount of fossil fuels used for cooling and heating is reduced.

Green roofs, or those totally or partially covered with vegetation, can also play an important role in saving energy, and reducing the urban heat island effect.

Furthermore, leaving grass clippings in your lawn to decompose releases valuable nutrients back into the soil to feed the grass, reducing the need for nitrogen by 25-50 percent.

In Metro Manila, I see the Bonifacio Global City in Taguig, Filinvest City in Muntinlupa, and the newly planned Clark Green City in Pampanga as having great potential to become smart and green cities.

But we need more green and smart cities in the Philippines, and it is the youth who should be strongly advocating and working for their establishment. Eventually, it is the youth of today who will be building the green and smart cities of the future.

Congratulations to the 2017 science awardees. It is also worth recognizing the efforts of Fidelina Corcuera of BPI Foundation, and DOST represented by Science Education Institute Director Josette Biyo for nurturing the science awards.

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2 Comments

  1. Rene L. Limosinero on

    Sir, I will share these with my students in Agricultural Extension and Communication.