The world’s production industries have generated tremendous amounts of economic growth since the 1800s, but the industrialization of cities has also led to significant challenges such as overcrowding and extreme pollution. Because urban environments are often home to many industrial facilities, people come to the city seeking employment, but large metropolitan hubs are running out of space to house their residents. With overcrowding, resource demands are increased, and as cities grow, urban environments may face more pressure in their attempts to provide large urban populations with sustainable supportive infrastructures like food, water, and safe roads. Advanced civil engineers are needed now more than ever to provide solutions to these critical issues; below are several developing innovations currently being used around the world to improve socio-environmental sustainability.
As a response to massive local waste and plastic pollution within their country, India’s government began experimenting with plastic roads during the early 2000s, with waste plastic being used as a construction material. An early report by India’s Central Pollution Control Board discovered that even after four years of use, Jambulingam Street in Chennai—one of the first plastic roads—had not sustained much damage. The board cited that no potholes, rutting, raveling, or edge flaws were discovered during the evaluation. This level of performance attracted the interests of local governments, who were looking to rid the Tamil Nadu region’s urban environments of the discarded shopping bags, foam packaging, and other unrecyclable plastic products that litter the streets. As of 2015, any Indian city with a population of at least 500,000 is required to construct their roads using waste plastic as a core material, in efforts to promote greater pollution control and environmental sustainability for Indian communities.
Although the concept of using waste plastic in roads is still in its early stages, with very few plastic roads currently existing in the Western world, civil engineering researchers in countries like the United Kingdom and the United States are working to design new technologies to support the safe implementation of waste plastic in road construction. One such development involves converting waste plastics into small balls that, when combined with asphalt or other common road components, create a strong, permeable surface that features hollow spaces that allow stormwater to seep through the road and more effectively recharge groundwater.
Transitioning to the use of plastic roads will lead to more manageable plastic waste and potentially, safer roads, but there are still some concerns regarding hazards that
accompany plastic roads as they age. As these roads gradually deteriorate due to heat and light, they may dissolve into micro-plastics that give off harmful pollutants, affecting the functionality and biodiversity of soil and water resources. Creative civil engineers play a significant role in ensuring that the science behind using waste plastic for roads is accurate, and that future iterations of this concept are carried out with consideration for environmental health and safety.
Green Roof Systems
The Environmental Protection Agency defines a green roof as a “vegetative layer grown on a rooftop.” Today, green roof systems have become popular all over the world, not only for their beauty, but also for the benefits they provide toward environmental sustainability. Germany is currently leading the world in green roof technologies, and they have implemented green roofing systems on approximately 10% of German homes since the technology emerged in the early 1970s. Civil engineers are responsible for ensuring that the green roof’s supportive infrastructure—for instance, a comprehensive watering system—is engineered to consistently deliver an appropriate amount of resources, and the roof itself must be designed to effectively provide working improvements to environmental sustainability.
However, civil engineers still face some obstacles when planning the installation and maintenance of green roof systems, like high costs and harsh climates, but innovations in modern engineering techniques for green roofing systems have allowed the industry to consistently offer the following environmental benefits to urban communities:
- Enhanced Urban Biodiversity: Green roofs accommodate new flora, which may act as new habitats for different species of plants and animals.
- Cooling of Buildings: The vegetation on the roof acts as thermal insulation, storing excess heat and decreasing peak temperatures within the building. This means less energy must be consumed to heat the building, resulting in decreased energy costs and lower pollutant emissions.
- Reduced Runoff Quantity: On average, green roofs retain 40-60% of total rainfall. Storing this rainwater as it falls has been shown to result in runoff reduction of 34% between September and February, and 67% between March and August. By reducing runoff, civil engineers that design green roof systems can limit strain on sewage systems and mitigate the costs of roof damage.
- Pollution Control: Green roofs are composed of plants that absorb nitrogen, lead, zinc, and airborne pollutants like carbon dioxide. This absorption also reduces the negative effects of acid rain by raising the pH values of acid rainwater before it becomes runoff water.
Eco Floating Homes
Affordable housing and overcrowding in cities are putting pressure on urban populations to make changes. To combat these issues, civil engineers are designing floating homes—practical living spaces that sit upon the water. The homes are designed to resist floods by floating on top of water using a foundation of concrete and Styrofoam, which makes them virtually unsinkable. This approach means that homes can be built in spaces that were previously off-limits, like rivers, lakes and other bodies of water. Civil engineers predict that modern floating home technology will lower the costs of flood damage in urban cities, while also providing compact inner-city populations with more diverse housing options.
The concept of floating buildings is not new, as they can be found all over the world, especially in traditional Asian villages. Although with modern civil engineering knowledge, these structures—and the infrastructure needed to make them sustainable—are gradually becoming more reliable and easier to maintain. However, introducing this concept in urban environments with large populations will prove to be somewhat tricky, as structures being built within or on above-ground water sources could impact environments negatively by disturbing the natural state of the land beneath bodies of water (e.g. lake bottoms or the ocean floor). The effect of humans on the environment should not be underestimated either, so civil engineers will need to remain focused on creating systems that inhibit floating houses and their residents from disrupting local water ecosystems, while improving the viability of this technology for use in low-income areas.
Using multistory high-rises to grow food is known as “vertical farming,” and The Association for Vertical Farming has found that, when compared with traditional agricultural methods, growing food indoors uses 98 percent less water and 70 percent less fertilizer on average. To generate the amount of light and water necessary to keep plants healthy, while remaining as cost-effective as possible, vertical farmers use a combination of energy efficient LED lights and hydroponic technology (plumbing, irrigation, filtration). By implementing modern automation techniques to regulate these systems, civil engineers can also limit the cost of labor required to maintain these farms. The costs associated with vertical farming are still quite high, but as science in this field advances, civil engineers will be able to provide the populations of un-farmable regions with opportunities to grow their own natural produce.
Many entrepreneurs and scientists are currently evaluating how growing food inside of buildings coincides with improving social and environmental sustainability. Vertical farms also have higher yields than traditional farms, allowing the production of more food, using far less urban space. Significant progress in the study of vertical farming could lead to improved food diversity, especially for residents of population-dense urban areas and in places that are normally unable to grow produce using traditional methods.
Harvesting rainwater is a climate adaptation strategy that has been used in many ancient and modern societies. The antiquated rainwater harvesting techniques of the past were attempts to cope with severe climate conditions by storing the water as it fell, allowing populations to drink the water or prevent oversaturation of the land during extreme precipitation. Modern rainwater harvesting is fundamentally the same in theory, but advancements in science and engineering have introduced sophisticated filtration and rain-capturing technologies that boost the efficiency of the process.
Dutch engineers and researchers have observed that effective large-scale implementation of rainwater harvesting infrastructure can reduce stormwater runoff by 20 to 50 percent, mitigating the strain that excess storm precipitation usually places on sewers and drainage systems. This is made possible by mounting rainwater catchment devices on the roofs of buildings, then routing the rainwater that is collected by the catchment through a treatment system and into a storage tank. To ensure the effectiveness of these rainwater-harvesting systems, the contents of each storage tank must be depleted before significant rainfall events occur. Therefore, civil engineers must obtain the knowledge and experience necessary to analyze the precipitation patterns and water usage rates of a region before installing any rainwater harvesting systems. With cost-effective approaches to the catchment, storage, and filtration technology used in rainwater harvesting currently being implemented and improved, large-scale rainwater collection is poised to become a widely used, economically viable solution to urban potable water shortages and stormwater management.
Large cities often come with many social benefits, but there will always be disadvantages to having large populations that are constricted to a finite amount of space. Ensuring that humans can live sustainably in highly populated urban environments requires creative solutions to infrastructural issues like road safety, housing crises, and food and water shortages. An advanced degree in civil engineering will provide an individual with an in-depth understanding of the environmental, structural, and infrastructural engineering knowledge required to work with the civil engineering innovations listed above.
As the nation’s oldest private military college, Norwich University has been a leader in innovative education since 1819. Through its online programs, Norwich delivers relevant and applicable curricula that allow its students to make a positive impact on their places of work and their communities.
Norwich University offers exceptional opportunities to help advance your knowledge, target your skills, and gain greater proficiency as a professional civil engineer. The online Master of Civil Engineering program at Norwich University is designed to enhance your technical knowledge, management skills and engineering competence by delivering a modern, practice-orientated education that fosters creativity and critical thinking for problem-solving and innovation.
Rainwater harvesting, a sustainable solution for urban climate adaptation?, Knowledge for Climate