Tag Archives: urban

Rumble in the concrete jungle: what history teaches us about urban defense

Given ongoing events in Ukraine, the age-old adage that offense is the best defense is being put to the test. So far, throughout the country’s towns and cities, the answer seems to be “not so much”.

Urban Urban Design Landscape Desing Qom Iran

With that being said, history gives us ample examples and wisdom on how best to handle urban combat in general and urban defense in particular. Fighting in such environments is a very different beast to combat in other types of landscapes, and it raises unique challenges, as well as offering its own set of options and opportunities. Many of these are related to the huge availability of solid cover and line-of-sight denial. Others arise from the way cities naturally funnel pedestrian and vehicle traffic, constraining them to known and predictable avenues.

So today, we will go through wisdom gathered painfully, at great cost of human lives and material damage over history, on how defenders can best employ built environments against attackers.

Erzats fortresses

In olden days, architects would design fortresses so that the defenders would have as much of an advantage over attackers as possible. The first and most obvious advantage is the physical protection afforded by thick, sturdy walls.

While most buildings today aren’t built to repel invaders, they do offer sturdy bases that defenders can use when bracing for an attack. Structures erected from concrete and rebar are especially tough and can act as impromptu fortifications. Most government buildings, apartment blocks, and office complexes are ideal for this role, as are banks.

If defenders have enough time to dig in, such buildings should be reinforced with materials such as lumber, steel girders, or sandbags. Such elements should be used to protect the structure from direct damage, help maintain integrity after damage is inflicted on the building, or cover areas through which attackers can enter the perimeter. Ideally, combat engineers would carry out reinforcement works, but if they are not available, civilians can fill the role partially.

Mines, barbed wire, and other physical barriers can also be used to deny attackers entry points into the building and make it hard for them to approach the site. Furniture, rubble, barbed wire, and mines should also be used to block or limit access to stairways and elevators; even if these do not neutralize any of the attackers, they can still delay a fighting force massively. Such makeshift defenses require a lot of time, effort, and resources (such as explosives and specialized combat engineers) to remove.

Inside the building itself, reinforcing materials should be used to create bunkers or similar fighting compartments that break a building’s open floors into multiple areas of overlapping fire.

Like for ancient fortresses, however, the key to picking the right building to fortify is location. Strongpoints should have a good command of their surroundings (direct line of sight for soldiers to fire). Several close-together buildings can be fortified to ensure overlapping fields of fire that the enemy cannot hide from. Whether fortified alone or in groups, these buildings should be surrounded by obstacle courses that prevent attackers from simply bypassing them, or isolating the strongpoint from support from other defending units.

Heavy weapons such as rocket launchers, guns, automatic cannons, and heavy machine guns can also benefit from an elevated position from which to fire. Such weapons can be disassembled, carried to upper floors, and reassembled for use. Equipment such as this can allow defenders to halt entire armored columns.

A single fortified building can completely blunt even an armored assault, or at least stall it. One such building — known today as “Pavlov’s House” — became famous during the Battle of Stalingrad in 1942. A platoon led by Sergeant Yakov Pavlov held out in this house against the German army for 60 days, repelling infantry and armored attacks. The soldiers surrounded the building with barbed wires and mines, broke holes through the interior walls to allow for movement, dug machinegun emplacements in the building’s corners, and used the top floors to lay down anti-tank rifle fire on advancing tanks. When artillery would fire on the building, they retreated to the safety of the cellar, only to re-emerge and continue fighting.

Such stories illustrate just how hard it can be for attackers to negotiate a single fortified building. Still, modern battlefields involve systems that were not available during World War II, so one extra element should be considered:


The advent of modern surveillance systems such as drones, satellites, and reconnaissance planes, together with the precision weapons in use today, means that strongpoints are at risk of precision strikes. Concealment saves lives, so defenders should take steps to hide their exact position and activity as much as possible.

Citizens embroiled in the Syrian conflict would routinely hang large pieces of cloth, tarps, or sheet metal in between buildings to hide personnel from snipers and aircraft. Such measures are disproportionally effective compared to their simplicity. Soldiers rely on sight heavily on the battlefield and don’t generally shoot unless they have reliable knowledge of where the enemy might be. In the case of heavy weaponry such as tank- or aircraft-mounted munitions, this is even more true. A pilot is much less likely to drop a bomb without a clear sighting than a soldier is to fire a single shot.

Even if the enemy chooses to fire, concealment measures still bring value to defenders. A weapon fired at an empty emplacement is effectively wasted, and cannot be used against an active defender — contributing to the so-called ‘virtual attrition’ of the attacking forces.

Concealment measures should be used in conjuncture with fortifications to hide the defenders’ movements and decrease the efficacy of enemy fire. Even so, a big fortified apartment building is hard to hide, and will undoubtedly draw some heavy ordinance its way. So another element should be considered to ensure the safety of defending soldiers.

Tunnels, mouseholes

Mouseholes are openings cut out to allow soldiers easy access through the interior as well as exterior walls of a building. They have been a mainstay of urban combat ever since the advent of gunpowder weaponry. Mouseholes can be created using explosives or simple tools, and should comfortably fit a soldier so as not to clog traffic during a tense situation. In the case that a building should be run over by the attackers, defenders can also use mouseholes as chokepoints to contain the enemy’s advance by covering them with machine-gun fire or personal weapons.

Tunnels, on the other hand, are dug underground. They require significantly more work than mouseholes but have the added benefit of concealing and protecting troops that transit them from fire. Due to their nature, tunnel networks are hard to set up, so they should be used to allow strategic access to important sites and give defenders safe avenues of reinforcing strongpoints. Whenever possible, defenders should work to build extensive tunnel networks to give troops safe avenues of passage on the battlefield.

Underground transportation avenues and infrastructure, such as metro lines or sewage lines, can also be used as tunnels and bunkers. German soldiers used them to great effect during the Battle of Berlin in 1945 to cause great pain to Soviet soldiers moving into the city. Such infrastructure is usually roomy enough to also be usable as hospital and storage space, is extensive enough to act as a communications network, and offers an ideal setting to set up ambushes, bunkers, or counter attacks. Some can even allow for the passage of armored vehicles. They are also sturdy enough — and dug deep enough underground — to withstand most artillery and airstrikes.

But what about other areas of the city?


As daunting as fortified spaces can be, the fact of the matter is that not every building can be fortified. There simply isn’t enough time, manpower, and material available when preparing a defense. But not every area needs to be fortified to help stop an attack. Sometimes, it’s as simple as tearing buildings down.

Defenders have the advantage that they can use the terrain in their favor to a much greater extent than attackers. They are the first of the two sides to hold a position, they know the land, and can take up the best spots to punish any invaders. Rubbling buildings can help in this regard on several levels.

First, rubble presents a physical barrier that an invading army will have difficulty navigating and removing. This is especially true for concrete or brick rubble produced by demolishing buildings. It forces attackers to move through pre-determined areas, where defenses can be set up to stop their advance. It also prevents them from using all their firepower on a single objective as it prevents direct fire. Rubble serves to also block line of sight, thus limiting the ability of an attacking force to keep tabs on what the defenders are doing.

Rubbling is, understandably, a very damaging process and thus quite regrettable to use. But it does bring huge benefits to defenders by allowing them to alter the landscape to their purposes.


Although less effective than rubbling at containing an enemy’s movements, barricades can be surprisingly effective at stopping both infantry and armored vehicles. Furniture, tires, sandbags, metallic elements, and wire all make for good barricades.

Urban landscapes are also very rich in objects that can be used for barricades such as trash containers, cars, manholes, industrial piping, and so forth. These should be used liberally and ideally set up in areas where defenders can unleash fire on any attackers attempting to navigate or remove them.

Concrete barriers

These aren’t very common in cities, but any checkpoint or protected infrastructure site might have some of these barriers. If you have time and concrete to spare, makeshift barriers can also be quite effective. They usually come in 3ft / 1 m tall anti-vehicle walls or 12ft / 4 m tall wall segments used by the military to reinforce strategic points.

These are essentially portable fortifications. They are made of rebar and concrete and are exceedingly hard to destroy directly. Use cranes and heavy trucks to move them, as they weigh a few tons each.


Another important advantage defenders have is that the attackers have to come to them — so there’s not much need to carry supplies to the front line.

Pre-prepared ammo caches can be strewn throughout the city to keep defenders in the fight as long as possible. Urban landscapes offer a lot of hidden spots where ammo or weapons can be deposited discretely. Food, water, and medical supplies are also essential, so make sure these are distributed throughout the engagement zone as well.

Strongpoints should have designated rooms for storage of such supplies. Smaller items such as magazines or grenades can be distributed in smaller quantities throughout several points of the building, to ensure that soldiers always have what they need on hand.

Attacking an urban environment is a very daunting proposition even for the most well-trained of military forces. It gives defenders an ideal landscape to set up ambushes, entrench, deceive their attackers, and launch counter-offensives. Making the most of the terrain, and preparing carefully, can give defenders a huge upper hand against their foes while making it hard for attackers to leverage their strengths. such landscapes can level the playing field even against a superior attacking force. The events in Ukraine stand as a testament to this.

Small towns are bigger than we think — and the world is more connected than ever

Here’s a mental experiment: take a moment to ponder the entire global population and where they live. Some, your mind will envision, are in the sprawling megacities of the world, while others are in smaller towns or villages. How many live in remote areas?

According to a new study, less than one percent of the global population lives in truly remote hinterlands. The surprising study shows that smaller cities and their surrounding areas are having an increasing influence on people’s livelihoods, contradicting the narrative that big cities are where most development happens.

How long it takes to get to large towns. Image credits: FAO.

Not islands

Since the industrial revolution truly took over in the 20th century, mankind has slowly moved from rural areas to urban areas. We’ve also become more connected, thanks to trains, cars, and more recently, planes. But according to a new study, even areas that are mostly rural (and you might think, isolated) are usually pretty well-connected.

The study analyzed multiple spatial datasets and calculated the time needed for rural populations to reach nearby urban centers. This is the so-called peri-urban area.

Cities often sprawl about, growing unrestrictedly in their desire to provide housing and commercial development towards the edge of the city. Thus, the ‘edge’ of the city gets pushed more and more, until it’s not clear where the city ends, and where neighboring areas begin. There’s no real agreement as to how to classify ‘peri-urban’, but typically, even a sprawling, sparsely-populated area around a city can be considered peri-urban.

According to the new study, 40% of the planet’s population lives in peri-urban areas, which is not necessarily surprising. What was surprising is that this 40% are almost equally distributed around small, intermediate, and large cities. Furthermore, small and intermediate towns seem to draw more inhabitants into their orbit than large cities.

The problem is that peri-urban environments often slip through the cracks of regulation and policy. They were traditionally considered rural, countryside environments, but as cities continue to expand, this is starting to change. Designing and managing areas in a way that’s suitable for both farmers and city dwellers is challenging, the researchers highlight.

“Rural and urban have been thought of as separate for too long. Development planning needs to focus on rural people’s access to employment opportunities and services in nearby urban centers, and acknowledge that urban centers are not islands upon themselves,” said Food and Agriculture Organization Senior Economist Andrea Cattaneo.

Mountain valleys of industrialised countries (e.g. Inn valley) are often periurbanised. Image credits: Lonesome Crow.

But what is perhaps even more striking is the percentage of residents that live in isolated hinterlands — areas defined as needing more than three hours — measured in terms of the available mode of transit from an urban settlement — to get to a town (of over 20,000 people). Just three countries have more than 5% of their population living in hinterlands: Madagascar, Niger, and Zimbabwe. Globally, less than 1% of the world’s population lives in these isolated areas.

The findings build on an overly simplistic view that higher-income countries are more urban. Real development is more complex, and often falls in the grey peri-urban area that’s neither truly urban nor rural.

Another important finding concerns food supply chains. The dominance of these peri-urban landscapes, combined with the fact that the urban and rural components are managed differently, suggests that local food chains could be managed more effectively and sustainably through local collaboration between farmers and urban dwellers.

“Agri-food chains connect rural and urban areas,” said Professor Andy Nelson from the Faculty of Geo-Information Science and Earth Observation, University of Twente in the Netherlands, and a co-author of the study. “Our data set supports both research and policy for transforming food systems to sustainably meet the increasing demands of urban markets.”

However, the importance of large cities should still not be underestimated: 40% of the world’s urban population (and almost 50% in Latin America and the Caribbean) live in large cities.

The study was published in Proceedings of the National Academy of Sciences.

Urban farming can feed surprisingly many people — at least in Sheffield

Using 10% of a city’s green spaces such as gardens and urban parks could provide the fruit and vegetables to feed 15% of the local population, according to a new study.

Gateway Greening Urban Farm, St. Louis, Missouri.
Image via Wikimedia.

Researchers at the Institute for Sustainable Food at the University of Sheffield analyzed the potential of urban horticulture in feeding Sheffield citizens by mapping its green and grey spaces.

Domestic gardens, allotments, and suitable public green spaces put together would correspond to 98 square meters per person in Sheffield for growing food. Commercial horticulture across the UK currently uses around 23 square meters per person, the paper adds.

Local produce

Green spaces cover around 45% of the city, which is similar to other cities in the UK. Allotments represent 1.3% of this surface, with domestic gardens, which have immediate potential to start growing food, making up 38%.

Using data from Ordnance Survey and Google Earth, the team showed that a further 15% of the city’s green space (such as parks and roadside verges) could also be converted into community gardens relatively easily.

If all the green areas in Sheffield were to be turned over for food production, the team estimates it could provide fruits and vegetables for approximately 709,000 people per year (that number is, currently, 122% of the city’s population). But even if only 10% of available green space is used to grow food, it could provide for 87,375 people, or 15% of the city’s population. The team explains that this would greatly improve the UK’s food security, by increasing the share of locally-grown food in the economy.

The team also analyzed soil-free farming on flat roofs through means such as hydroponics (plants grown in a nutrient solution), and aquaponics (a system combining fish and plants). Such farms would allow year-round growing of food with minimal lighting requirements, and virtually no ecological impact — the greenhouses would be powered by renewable energy and heat captured from buildings, with rainwater harvesting for irrigation. The 32 hectares of flat roof cover in Sheffield would translate to only half a square meter per local, but the team says it could have a significant impact on local food security.

“At the moment, the UK is utterly dependent on complex international supply chains for the vast majority of our fruit and half of our veg — but our research suggests there is more than enough space to grow what we need on our doorsteps,” says Dr. Jill Edmondson, Environmental Scientist at the University of Sheffield and lead author of the study.

“Even farming a small percentage of available land could transform the health of urban populations, enhance a city’s environment and help build a more resilient food system.”

The paper “The hidden potential of urban horticulture” has been published in the journal Nature Food.

More green spaces can help some cities keep cool

Researchers looking into how to help keep our cities cool say that more green spaces can help, although not everywhere.

Image credits Khusen Rustamov.

The urban heat island effect is a phenomenon through which the temperature in a city is noticeably higher than in the surrounding rural area. Which is, obviously, very irritating.

In a bid to find out how to control the effect, an international team of researchers looked at the role of precipitation and population size have on city temperatures compared with the surrounding countryside. All in all, they report that more green spaces can help bring city temperatures down, but not everywhere.

Plant some plants

“We already know that plants create a more pleasant environment in a city, but we wanted to quantify how many green spaces are actually needed to produce a significant cooling effect,” says Gabriele Manoli, former postdoc with the Chair of Hydrology and Water Resources Management at ETH Zurich and lead author of the study.

When urban heat island effects compound with the sort of heatwaves that hit most of Europe this summer, it can pose a very real and deadly threat to the elderly, sick, and other vulnerable groups.

The team looked at urban heat islands across the globe and at the different heat-reduction strategies they employ. The effectiveness of these strategies depends heavily on regional climate, they explain.

Manoli and his team — with members from ETH Zurich, Princeton University and Duke University — studied data from around 30,000 cities worldwide and their surrounding environments. The factors they analyzed include average summer temperatures, population size, and average annual rainfall.

The larger the city, the more dramatic its urban heat island, the authors explain — but also more rainfall in the region. As a rule of thumb, more rain means more plant growth, meaning that areas surrounding large cities are much cooler than them. This effect is the strongest when annual rainfall averages around 1500 millimeters (as in Tokyo), but does not increase further with more rain.

Cities in very dry regions (like Phoenix, Arizona) can, through carefully-targeted planting efforts, bring their average temperatures below that of the surrounding countryside. Those surrounded by tropical forests on the other hand (such as Singapore) would need far more green spaces to reduce temperatures — but the authors warn that this would also increase humidity.

Therefore, cities located in tropical zones should look to other cooling methods, such as increased wind circulation, more use of shade, and new heat-dispersing materials.

One of the main takeaways from the study, Manoli explains, is a preliminary classification of cities to help guide planners on possible approaches to mitigate the urban heat island effect.

“There is no single solution,” Manoli says. “It all depends on the surrounding environment and regional climate characteristics.”

“Even so, searching for solutions to reduce temperatures in specific cities will require additional analysis and in-depth understanding of the microclimate. Such information, however, is based on data and models available to city planners and decision-makers only in a handful of cities, such as Zurich, Singapore or London.”

The team is now working to determine which types of plant are most useful for reducing the heat island effect.

The paper “Magnitude of urban heat islands largely explained by climate and population” has been published in the journal Nature.

Central Park.

Urban parks make people ‘as happy as Christmas’ — at least on Twitter

A quick walk in the park may just be the emotional pick-me-up you need.

Image credits Maleah Land.

The first study of its kind shows that those who visited an urban park use happier language and express less negativity on Twitter than before the visit. This boost in mood, the paper further reports, can last for up to four hours afterward.

Christmas come early

“We found that, yes, across all the tweets, people are happier in parks,” says Aaron Schwartz, a University of Vermont (UVM) graduate student who led the new research, “but the effect was stronger in large regional parks with extensive tree cover and vegetation.”

The effect is definitely strong — the team found that the increase in happiness people derived from visiting an area of urban nature was equivalent to the mood spikes seen on Christmas day (which they explain is by far the happiest day of the year on Twitter). Given that more and more of us live and work in the city — and given the growing rate of mood disorders we experience — the findings can help inform public health and urban planning strategies.

For the study, the team spent three months analyzing hundreds of tweets daily that were posted from 160 parks in San Francisco. Visitors showed the effects of elevated mood in their posts after visiting any one of these urban nature areas. Smaller neighborhood parks showed a more modest spike in positive mood, while mostly-paved civic plazas and squares showed the least mood elevation.

This suggests that it wasn’t merely going out of work, or being outside, that caused the boost in mood. The team says areas with more vegetation had the most pronounced impact, noting that one of the words that shows the biggest uptick in use in tweets from parks is “flowers.”

“In cities, big green spaces are very important for people’s sense of well-being,” says Schwartz.

“We’re seeing more and more evidence that it’s central to promoting mental health,” says Taylor Ricketts, a co-author on the new study and director of the Gund Institute for Environment at UVM.

The study’s findings are important as they quantify the benefits of natural areas beyond immediate monetary gains (i.e. “how many dollars of flood damage did we avoid by restoring a wetland?”) and look at its direct effects on public health.

Image via Pixabay.

The team used an online instrument called a hedonometer — invented by a team of scientists at UVM and The MITRE Corporation — to gather and analyze the tweets. The instrument uses a body of about 10,000 common words that have been scored by a large pool of volunteers for what the scientists call their “psychological valence,” a kind of measure of each word’s emotional temperature.

The volunteers ranked words they perceived as the happiest near the top of a 1-9 scale, with sad words near the bottom. Each word’s final score was calculated by averaging the volunteers’ responses. “Happy”, for example, ranked 8.30, “hahaha” 7.94, and “parks” 7.14. Neutral words like “and” and “the” scored 5.22 and 4.98. At the bottom were “trapped” 3.08, “crash” 2.60, and “jail” 1.76.

Using these scores, the team combed through the tweets of 4,688 users who publicly identify their location and were geotagged with latitude and longitude in the city of San Francisco (so they could pinpoint exactly which park they were tweeting from).

“Then, working with the U.S. Forest Service, we developed some new techniques for mapping vegetation of urban areas–at a very detailed resolution, about a thousand times more detailed than existing methods,” says study co-author Jarlath O’Neil-Dunne, director of UVM’s Spatial Analysis Laboratory in the UVM Rubenstein School of Environment and Natural Resources and a co-author on the new study.

“That’s what really enabled us to get an accurate understanding of how the greenness and vegetation of these urban areas relates to people’s sentiment there.”

Overall, the tweets posted from urban parks in San Francisco were 0.23 points happier on the hedonometer scale over the baseline. The increase is “equivalent to that of Christmas Day for Twitter as a whole in the same year,” the scientists write.

Exactly why parks have this effect on people isn’t fully understood — and wasn’t the object of the present study. Regardless of how it happens, the results suggest that people tend to be happier in nature. That’s a finding “that may help public health officials and governments make plans and investments,” says UVM’s Aaron Schwartz.

The paper “Visitors to urban greenspace have higher sentiment and lower negativity on Twitter” has been published in the journal People and Nature.

Tree park.

The US lost roughly 1 in every 100 urban trees between 2009 and 2014

The USDA Forest Service estimates that the country has lost approximately 36 million urban/community trees per year between 2009 and 2014.

Tree park.

Image credits Albrecht Fietz.

If you’re an American who likes stepping out in the street right under the shade of a tree, the USDAFS has bad news for you — the country’s cities and towns are running slim on trees. Roughly 0.7% of the nation’s urban trees have been felled between 2009 and 2014, which equals approximately 36 million trees, or 175,000 acres of tree cover lost annually over that period.

Fewer trees

Overall national urban tree cover declined from 42.9% to 42.2% over that period, the report states. However, the losses weren’t spread uniformly across the US; 23 states had a statistically significant decrease in urban tree cover, while 45 states showed a net decline.

“Urban forests are a vital part of the nation’s landscape,” said co-author Tony Ferguson, Director of the Forest Service’s Northern Research Station and the Forest Products Laboratory. “Forest Service research puts knowledge and tools into the hands of urban forest managers that supports stewardship and the wise allocation of resources.”

Trees help filter air and water, improving their quality, which is especially nice in urban areas, that tend to see the highest levels of pollution. They also help keep down energy bills in the summer by keeping buildings cool. Other benefits urban trees provide include noise reduction, mitigation of runoff and flooding, as well as enhancing our mood and mental well-being, and having a positive effect on health. Overall, the benefits derived from urban forests in the US is estimated at some $18 billion annually, in the form of air pollution removal, carbon sequestration, and lowered building energy use.

The states or districts with the greatest annual net loss in urban tree cover were Rhode Island and the District of Columbia (0.44%), Georgia (0.40%), and Alabama and Nebraska (0.32% each). The states that lost the most tree cover per year were Georgia (18,830 acres/year), Florida (18,060 acres/year) and Alabama (12,890 acres/year).

Mississippi, Montana, and New Mexico saw slight (statistically non-significant) increases in urban tree cover. Maine recorded the highest percentage of urban tree cover across the US — 68%. North Dakota, with just 10%, ranked the lowest.

“Urban forests are an important resource,” said Dave Nowak of the USDA Forest Service’s Northern Research Station, co-author of the study. “Urban foresters, planners and decision-makers need to understand trends in urban forests so they can develop and maintain sufficient levels of tree cover — and the accompanying forest benefits — for current and future generations of citizens.”

Over the same period, urban/community impervious cover (concrete, buildings, so on) saw a statistically-significant increase, from 14.5% to 15.1%. States that saw the greatest annual net percent increase in impervious cover were Delaware (0.28%), Iowa (0.26%), Colorado, Kansas and Ohio (with 0.24% each). States with the greatest net increase in impervious cover were Texas (17,590 acres/year), Florida (13,900 acres/year), and Ohio (8,670 acres/year).

The study comes to flesh out previous research of the USDAFS, looking into the role urban forests will play in future cities.

The paper “Declining urban and community tree cover in the United States” has been published in the journal Urban Forestry & Urban Greening.

Chaotic cities are cooler than orderly ones, researchers report

A new paper reports that street and building layout plays a major role in a city’s urban heat island effect, which makes them hotter than their surroundings.


Cities with an orderly pattern have a much greater urban heat island effect than those with a more disorderly pattern.
Image credits Pellenq et al., 2018, Physical Rev. Letters.

If you’re an American living in a big city, you’re probably used to all the streets and buildings being laid out in an orderly grid. If you happen to be European, not so much — our cities still sport the chaotic, sprawling road networks set down ages ago. While it can make navigation a pain, the latter can also help keep cities cool, according to new research led by MIT and National Center for Scientific Research senior research scientist Roland Pellenq.

The findings suggest that cities laid out in precise grids, like New York or Chicago, experience a far greater buildup of heat relative to their surroundings than those arranged more chaotically, like London or Boston.

The Hot Grid

The heat island effect is a product of the fact that building materials, like concrete, absorb heat during the day and radiate it out at night. Natural areas also trap some heat, but it’s a tiny amount compared to cities — mostly because plants use up incoming sunlight during photosynthesis. Heat island effects can make cities over 5° Celsius (10° Fahrenheit) warmer than surroundings, in areas that get a lot of sunlight. It can cause health issues for city dwellers and causes energy use to spike during hot weather. So, a better understanding of the effect can improve quality of life for residents and presents (several) economic advantages to boot.

To explore the heat island effect, the team adapted mathematical models that were developed to analyze the atomic structures in materials, developing a new and straightforward method to study the relationship between a city’s design and its heat-island effect. Such systems describe how individual atoms in a material are influenced by other atoms, and the team reduced the simulation to much simpler, statistical descriptions of how far away buildings are from each other. Then, they applied them to patterns of buildings in 47 cities, from the U.S. and also from other countries.

Each city was thus ascribed a ‘local order parameter,’ ranging between 0 (total disorder) and 1 (perfectly ordered structure, which is generally a description of how orderly atoms in a material are — typically, this parameter is obtained by bombarding a sample with neutrons. For this paper, however, Pellenq and his team used Google maps to pinpoint the location of each building. The cities included in the paper varied from 0.5 to 0.9 on their local order parameter.

Temperature data was recorded for each city by two stations — one within the city proper, and another outside but still close — which were used to determine the heat island effect in each case.

The team reports that the heat island effect seems to result from the interactions between buildings that radiate and re-radiate heat. This heat can be trapped by other buildings that face them directly, the team reports, meaning the city has a very hard time cooling off. They estimated that in the state of Florida alone, urban heat island effects lead to some $400 million in excess costs for air conditioning per year.

So, understanding how it works and planning around the effect might have significant benefits, especially for countries such as China that are rapidly building new cities, or areas of rapid urban expansion. In hot locations, cities could be designed to minimize the extra heating, while colder places might benefit from amplifying the effect.

“This gives a strategy for urban planners,” says Pellenq.

“If you’re planning a new section of Phoenix, you don’t want to build on a grid, since it’s already a very hot place. But somewhere in Canada, a mayor may say no, we’ll choose to use the grid, to keep the city warmer.”

Other important findings of the study are that research on construction materials can offer a way forward in regards to heat management and heat interactions between buildings.

The paper “Role of city texture in urban heat islands at nighttime” has been published in the journal Physical Review Letters.

Living in a park: Sydney’s One Central Park proves cities can be green

Sydney can boast the tallest vertical garden in the world. Completed in 2014, the city’s One Central Park is a towering residential building dressed in dazzling green plant garb.

They’re stuffy, they’re gray, they’re dusty — they are cities. To satisfy our ever-growing need for space, engineers have paved and built over green areas, leaving only a tiny sliver behind as parks. But cities and greenery can coexist marvelously, Parisian architect Jean Nouvel and French artist and botanist Patrick Blank believe. The duo’s vision was proven right in 2014 as Sydney’s 166 meter (544 feet) high One Central Park.

The residential high-rise is part of an “urban village” in downtown Sydney that houses residential towers, shops, and common spaces for artists and architects to enjoy. Cloaked in living greenery, OCP’s facade houses 250 species of native Australian plants hopping from balcony to balcony from a park at the heart of the complex. An assembly of motorized mirrors sprawls at the top to capture and direct sunlight down for the plants to enjoy. And after sunset, the building burst in LED lights designed by lighting artist Yann Kersalé to be renewably-powered.

The complex includes two residential towers atop a five-story Central shopping center. The western tower is 84 meters (275 feet) high and accommodates 240 homes, while the 117-meter-high (383 feet) eastern tower contains 383 apartments — including 38 penthouse flats with access rooftop sky garden.

Its name is no coincidence either. The spacious 6,500 square meter (69,965 sq. feet) park at the base of the complex is reminiscent of New York’s famous Central Park. With large open lawns, chessboards, an open air cinema, and spaces for festivals or concerts, it is the architects’ hope that this park will provide a respite from city life just like its counterpart in the US.

But it’s not all relax-this and enjoy-that. OCP and similar concepts serve as a blueprint for what many people hope urban architecture will become in the future. With concrete dominating skylines around the world, green-starved cities bake in their own tiny urban heat islands and smog. Combining built space with greenery could offer a healthy, environmentally-friendly alternative in the future.

“Hydroponic irrigation systems, for one, make it possible to grow a soil-less vertical veil of vegetation in planters and on walls all the way up to the tower tops. The resulting green facades trap carbon dioxide, emit oxygen and provide energy-saving shade,” said said Ateliers Jean Nouvel in a statement.

The concept has had huge success — all apartments list as “sold out” on One Central Park’s website.

Birds in suburbs defend their territory more aggressively than their rural counterparts

A new study found that birds living in urban environments in Southwest Virginia will engage in more aggressive behavior to defend their territory than their country counterparts.

Seeing as my city’s streets are choke full of pigeons that look like they couldn’t seriously harm a morsel of bread, it comes a bit hard for me to put the words “city,” “bird,” and “aggressive” in the same sentence. But it seems that I’ve been deceived — a new Virginia Tech paper found that city birds viciously defend their territories, employing very aggressive behavior to scare off other birds.

Get off my lawn!
Image credits Devra/Flickr

“A possible reason for this is that these birds have less space but better resources to defend,” said Scott Davies, a biological sciences postdoctoral associate in the College of Science. “Living near humans provides better food and shelter, but it also means more competition for these limited resources.”

The two man team, composed of Davies and assistant professor of biological sciences in the College of Science, spent the spring of 2015 measuring the territorial aggression of 35 urban and 38 rural male song sparrows at three rural and three urban sites in the New River Valley. Virginia Tech and Radford Uni campuses served as the urban sites, chosen for the high level of human interaction that animals here were assumed to have. Rural sites included Kentland Farm and Heritage Park.

Researchers played a recording of a male song sparrow at these locations and then observed the behavior of territory-holding birds to this simulated intrusion. Campus birds approached the speaker and remained near it, flapping their wings furiously, engaging in loud singing that later developed into “soft song” — a term that researchers use to describe the quiet, garbled noise that a bird makes before launching an attack. By contrast, rural birds still responded to the recording, but not as vigorously.

To make sure they weren’t testing the birds on their grumpyest, the researchers attached small leg bands on their legs to identify them. They checked each bird’s response twice, several weeks apart — suburban birds were more territorial on both occasions, suggesting that their aggressiveness persists throughout a breeding season.

The study gives us some insight into how cohabitation with humans affects wildlife – although many animals avoid habitats that are impacted by humans, some adjust and live in suburban, even urban habitats.

“This finding supports past research showing that urban birds are more aggressive in defending their territories,” said Kiki Sanford, a neurophysiologist who was not involved in the study.

“We need to understand widespread behavioral differences between various species of urban and rural bird populations to get an idea of how urbanization will affect their survival and diversity in the future. Testosterone and population density are the usual predictors for aggression, but there are other influential factors, like increased food availability in urban environments, that need to be examined.”

The full paper, titled “Agonistic urban birds: elevated territorial aggression of urban song sparrows is individually consistent within a breeding period” has been published in the journal Behavioral Ecology and can be read here.

European capital designates Natural Park right in the city

The Romanian government has approved the creation of the Vacaresti Nature Park inside Bucharest’s city limits. The park will be the biggest urban protected area in Europe.


Wildlife meets communist architecture. Image via parcnaturalvacaresti.ro

The park contains the wetlands surrounding the Vacaresti Lake, creating a delta-like habitat from a river bifurcation. Much of the swampy area surrounding the park was drained by Socialist Romania, building a neighbourhood of apartment blocks, something which subsequent city leaders have failed to rectify.

The idea of a natural park in a capital was an objective pushed forth by several scientists and environmental NGOs. This decision was hailed and even regarded as overdue, considering the area’s significant biodiversity.

“This historic decision for Bucharest and Romania will mean that the area that hosts at this moment over 97 protected species will have a special protection and conservation regime,” said a representative of Let’s Do it, Romania, one of the NGOs that has lobbied this project.

This is an important victory in itself, but it may become a starting point for future urban development across the old continent. As cities continue to grow more and more, they are often expanding into vulnerable natural areas, posing a huge threat for the wildlife surrounding the cities. The idea of having a natural park in or close to city boundaries, a “Delta between the blocks” as Vacaresti is called, is an important concept both for biodiversity and for the inhabitants of the city. A green oasis can work wonders, especially in heavily urbanized areas in Europe.

Image via parcnaturalvacaresti.ro

It also sends a message to the citizens of other cities. Despite housing over two million people, Bucharest is severely lacking in green spaces. Citizens have realized this, and they have pushed for the establishment of the natural park. If anything, it’s a park made by the people, for the people.

“Over the last almost 4 years, we have heard the word „impossible” many times, but this hard-earned victory proved that „it is possible”. We hope that this encourages the cities’ communities in their fight for every square meter of real green space”, declared Helmut Ignat, nature photographer and founding member of the Văcărești Nature Park Association.


Heart Disease affects Urban and Rural Dwellers Alike

According to a study from Women’s College Hospital and the Institute for Clinical Evaluative Sciences (ICES), Canada, it doesn’t matter whether you live in a rural or urban setting when it comes to heart disease – the risk if the same for both environments. The general consensus is that those living in rural areas are at a disadvantage as far as heart disease treatment is concerned, since they have less access to specialized facilities and turn out less regularly for checkups. The findings, however, show once a patient leaves the hospital their overall health outcomes are similar regardless of where they live.

No difference in heart disease prevalence between urban and rural


Credit: pxleyes.com

Heart disease, such as coronary heart disease, heart attack, congestive heart failure, and congenital heart disease, is the leading cause of death for men and women in the U.S.  The most common cause of heart disease is narrowing or blockage of the coronary arteries, the blood vessels that supply blood to the heart itself. This is called coronary artery disease and happens slowly over time and it’s the major reason people have heart attacks.

[AMAZING] Pig heart grafted to baboon abdomen survives for more than a year

The researchers  examined the records of more than 38,000 people with chronic ischemic heart disease living in either urban or rural areas. The key behavioral differences when it comes to heart disease between the two demographics, as identified by the researchers, were that rural people:

  • Had fewer specialist visits
  • Visited hospital emergency departments more frequently for care
  • Were prescribed statins less often
  • Were tested less frequently for cholesterol and blood sugar levels
  • Experienced a similar risk of hospitalization and death

Despite this discrepancy in access to health care facilities, this did not affect any of the two groups significantly, as reported in the journal Circulation: Cardiovascular Quality and Outcomes.

“From our study, we know that people with heart disease in rural areas tend to rely heavily on emergency departments for their care because of a lack of outpatient access to family doctors and specialists,” said Dr. Bhatia, also a scientist at ICES. “Yet, despite an increase in emergency department admissions in rural areas, we didn’t see worse health outcomes for these individuals.”

You can help reduce your risk of heart disease by taking steps to control factors that put you at greater risk:

  • Control your blood pressure
  • Lower your cholesterol
  • Don’t smoke
  • Get enough exercise

Does a green roof on a bus really make sense?

Greening the urban environment is not only pleasant to look at – it’s a necessity! But as cool as planting a green roof on a bus is, is this really an efficient way to go at it?

The good

I absolutely love green roofs – and I love innovative public transportation! It makes sense that I’d be a fan of this idea, wouldn’t it?

The matter was discussed in many places ranging from the UK’s (usually green skeptic) Daily Mail to the sustainable design folks at Inhabitat. The idea is to install “air purifying” green roofs on city buses. Here’s how the project’s founder, Marc Granen argues his case:

The lungs of a city must grow at the same rate as its population, but much-needed green areas are not always available. PhytoKinetic has grown out of this supposition, with the goal of delivering a practical and tangible solution. If finding new urban spaces for gardens is problematic, we can use spaces that already exist, such as the roofs of city public transport. Our mission is to expand the garden area in urban areas, increase the absorption of CO2 and give public transport a new ecological and tourist attraction.

The project features some very clever ideas, including irrigating the soil using the condensation from the buses’ own air conditioning systems. The project would reduce the temperature in the bus during the summer, and perhaps raise it very slightly during the winter. But it’s not all good.

The bad

Gardens are heavy – really heavy; and they’re not exactly aerodynamic either. Any additional weight on the bus means that it will consume more fuel. At full water capacity, the system adds 60kg/m2, or roughly the weight of one person every square meter. I wasn’t able to find any calculation on how much fuel this would actually spend, but it’s definitely significant!

Still, one could argue that the bus could only carry a reduced number of people to compensate for that weight, but the fewer people it carries, the lower efficiency it has – public transportation is only efficient and green if it carries many people. Adding such a garden would be a major hurdle here.

So any way you look at it, you either have to spend more fuel, or transport fewer people – both unsustainable options. So technically speaking, the cons outweigh or at least significantly draw back the benefits.

…and the ugly

No, not really. The one thing these gardens have for them is the looks – they really look beautiful, seen both from above and from ground level. Aesthetics and comfort are significant considerations as well, and I’m sure many people would be delighted to see them in their buses.

So when you draw the line, what’s the result? This is certainly a different idea, with some clever implementations, which would have a significant positive aesthetic effect. However, environmentally speaking, my opinion is that there are other, far more efficient and equally pleasant solutions which can be implemented.

Busting 8 of the weirdest science myths

Well you’ve probably all seen the Myth Busters. I’ve watched some episodes and loved most of them, so I’m hoping I can give them a hand. I haven’t watched all the episodes so if they (or anybody else) already took care of these myths well… oh well.

The duck’s quack doesn’t echo


This is one of the most quacky myths you can come across. Sorry to break your hearts guys, but the duck’s quack does have an echo. As far as I was able to find, there wasn’t anything to document this in the first place, it was just spread like plague, but there was (at least) a study to prove this wrong. If you want to read it, you can get it HERE. The myth probably arose because the echo is indeed more quiet then you would expect, and maybe they just don’t hang around good reflecting surfaces. I don’t know.

The chameleon’s tongue is 5 times longer than his body

The chameleon is a master of disguise, being able to change colurs to transmit social messages, describe how their feeling, and even to mimic the surrounding environment. That’s a fact. They also have long tongues which they hunt with, but nowhere near as long as popular belief has it. The chameleon’s tongue is about as long as his body, which is about 8-12 inches (10-30 cm). This, and other facts about this amazing animal HERE.

Sneezing myths

There’s a whole lot of myths about sneezing. Firstly, they say your heart stops when you sneeze, which can cause you problems if you sneeze hard or often. Wrong ! The heart’s intensity may rise or lower (nothing dangerous though), because just before sneezing you inhale a lot of air, thus increasing your lung pressure, and then quickly exhale.

Then there’s the thing with eyes. It’s also a common belief that you can’t keep your eyes open while you sneeze. I remember some friends and myself tried this for a month or so, and nobody succeeded in doing this. Well as it turns out, some people can actually sneeze with their eyes open, and even more than once. Yes, that means that your eyes don’t pop out if you keep them open while sneezing.

Turtles and bees are deaf


There’s still some debate here, because it depends on how you define deaf. Bees don’t have ears, so they don’t pick up sounds the way we do, but they do sense and distinguish between vibrations with their feet. They can actually pick up sounds we can’t, but it’s still unknown if they can interpret them as good as we do. It was believed for a long time that turtles are deaf too. They have auditory organs, and if they’re not responding to sounds, it’s probably just because they don’t care. Their hearing is probably very weak though.

A pencil thick spider’s silk thread is capable of stopping a Boeing-747

This is one of my favorite myths of all time. It has it all ! We know spider silk is one of the toughest substances known to man, so it’s believable. It’s just a pencil thick spider silk agains a huge plain, just like David and Goliath, and it’s man against nature, which (let’s face it) only has one winner. However, the spider wouldn’t stand a chance here. Even if the plane would be at landing speed (80 m/s) as opposed to full speed (>300 m/s), the spider thread would have to be 30 km long, which would require just above 100.000 million spiders to make. You really should take a look at this, which is where I took the numbers from. The calculations are indeed spectacular, and from what I can tell they are correct. A really interesting study indeed.

Canada has 1/3 of the world’s water

I’m not even sure if this is about drinkable water or any type of water, but the good thing is that it doesn’t matter. If it’s about drinking water, Canada is actually in the 3rd place, after Brasil and Russia; and if it’s about all water, well then, 70% percent of it is located at the Poles.

1 grade higher on the Richter scale means an earthquake 32 times powerful

Not technically a myth, but often used. The Richter scale is logarithmic scale, and 1 degree means actually an earthquake 10 times stronger. This probably comes from confusion with the Moment Magnitude Scale.

American astronauts have to be shorter than 1.80


Good news for you folks, that’s not true either. You have to be between 1.57 and 1.91 m. Now go and chase your dream !

Well, those are not all, but the most interesting things I was able to come across, so here’s hoping this makes you look witty when some of your friends are mentioning them, and if you know of any others, feel free to add them.