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77-460: Hong Kong Park is a public park next to Cotton Tree Drive in Central , Hong Kong . Built at a cost of HK$ 398 million and opened on 23 May 1991, it covers an area of 80,000 square metres (860,000 sq ft) and is an example of modern design and facilities blending with natural landscape. Part of the site was known as Cantonment Hill in early colonial days in 1841. At the upper part of

154-451: A 10-minute walk , provides multiple benefits. A park is an area of open space provided for recreational use, usually owned and maintained by a local government. Grass is typically kept short to discourage insect pests and to allow for the enjoyment of picnics and sporting activities. Trees are chosen for their beauty and to provide shade , with an increasing emphasis on reducing an urban heat island effect. Some early parks include

231-432: A city compared with surrounding rural areas." This relative warmth is caused by "heat trapping due to land use, the configuration and design of the built environment , including street layout and building size, the heat-absorbing properties of urban building materials, reduced ventilation, reduced greenery and water features, and domestic and industrial heat emissions generated directly from human activities". Throughout

308-401: A city is that trees also help fight global warming by absorbing CO 2 from the atmosphere. Painting rooftops white has become a common strategy to reduce the heat island effect. In cities, there are many dark coloured surfaces that absorb the heat of the sun in turn lowering the albedo of the city. White rooftops allow high solar reflectance and high solar emittance, increasing the albedo of

385-427: A distinct urban heat island, and the heat island characteristics depend strongly on the background climate of the area in which the city is located. The impact in a city can change a lot based on its local environment. Heat can be reduced by tree cover and green space which act as sources of shade and promote evaporative cooling. Other options include green roofs , passive daytime radiative cooling applications, and

462-524: A heat wave, as it deprives urban residents of the cool relief found in rural areas during the night. Increased temperatures have been reported to cause heat illnesses , such as heat stroke , heat exhaustion , heat syncope , and heat cramps . Extreme heat is the deadliest form of weather in the U.S. Per a study by Professor Terri Adams-Fuller, heat waves kill more people in the U.S. than hurricanes, floods, and tornadoes combined. These heat illnesses are more common within medium-to-large metro areas than

539-679: A large percentage of solar heat creating warmer near-surface temperatures. Paving with light-coloured concrete, in addition to replacing asphalt with light-coloured concrete, communities may be able to lower average temperatures. However, research into the interaction between reflective pavements and buildings has found that, unless the nearby buildings are fitted with reflective glass, solar radiation reflected off light-coloured pavements can increase building temperatures, increasing air conditioning demands. There are specific paint formulations for daytime radiative cooling that reflect up to 98.1% of sunlight. Green roofs are excellent insulators during

616-539: A result of this warming, monthly rainfall is about 28% greater between 20 and 40 miles (32 and 64 km) downwind of cities, compared with upwind. Some cities show a total precipitation increase of 51%. One study concluded that cities change the climate in area two–four times larger than their own area. One 1999 comparison between urban and rural areas proposed that urban heat island effects have little influence on global mean temperature trends . Others suggested that urban heat islands affect global climate by impacting

693-507: A result, high daytime surface temperatures within the UHI can be easily seen via thermal remote sensing . As is often the case with daytime heating, this warming also has the effect of generating convective winds within the urban boundary layer . At night, the situation reverses. The absence of solar heating leads to the decrease of atmospheric convection and the stabilization of urban boundary layer. If enough stabilization occurs, an inversion layer

770-710: A significant increase in Surface Urban Heat Island Intensity (SUHII) from 1985 to 2017, influenced by both geographic direction and time. This research, enhancing the understanding of SUHII's spatial and temporal variations, emphasizes the need for precise urban planning to mitigate the health impacts of urban heat islands. Surface UHI's are more prominent during the day and are measured using the land surface temperature and remote sensing. UHIs also impair water quality . Hot pavement and rooftop surfaces transfer their excess heat to stormwater, which then drains into storm sewers and raises water temperatures as it

847-474: A study by Hyunkuk Cho of Yeungnam University, an increased number of days with extreme heat each year correlates to a decrease in student test scores. High UHI intensity correlates with increased concentrations of air pollutants that gathered at night, which can affect the next day's air quality . These pollutants include volatile organic compounds , carbon monoxide , nitrogen oxides , and particulate matter . The production of these pollutants combined with

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924-616: A study by Professor Francisco Salamanca Palou and colleagues, this residual heat can cause nighttime increases of up to 1 °C in urban areas. Increased energy use from air conditioners also contributes to carbon emissions, which doubly exacerbates the effects of UHIs. Strategies to improve urban resilience by reducing excessive heat in cities include: Planting trees in cities, cool roofs (painted white or with reflective coating) and light-coloured concrete, green infrastructure (including green roofs ), passive daytime radiative cooling . The temperature difference between urban areas and

1001-441: A warming world, increasing air temperature makes the urban heat island effect in cities worse. One key risk is heatwaves in cities that are likely to affect half of the future global urban population, with negative impacts on human health and economic productivity." There are unhelpful interactions between heat and built infrastructure: These interactions increase the risk of heat stress for people living in cities. Aside from

1078-522: Is a greenhouse gas whose formation will accelerate with the increase of temperature. Climate change is not a cause but an amplifier of the urban heat island effect. The IPCC Sixth Assessment Report from 2022 summarized the available research accordingly: "Climate change increases heat stress risks in cities [...] and amplifies the urban heat island across Asian cities at 1.5 °C and 2 °C warming levels, both substantially larger than under present climates [...]." The report goes on to say: "In

1155-480: Is a secondary contributor. Urban areas occupy about 0.5% of the Earth's land surface but host more than half of the world's population. As a population center grows, it tends to expand its area and increase its average temperature. The term heat island is also used; the term can be used to refer to any area that is relatively hotter than the surrounding, but generally refers to human-disturbed areas. Monthly rainfall

1232-684: Is an outstanding example of modern design and facilities blending with the natural landscape . The construction of the park was a joint project by the Urban Council (dissolved in 1999) and the Royal Hong Kong Jockey Club (renamed the Hong Kong Jockey Club in 1996). A few historic buildings of former Victoria Barracks were also conserved in the park, including: These historic buildings are graded as Grade II Historic Buildings. The park can be easily reached by walking through

1309-462: Is formed. This traps urban air near the surface, keeping surface air warm from the still-warm urban surfaces, resulting in warmer nighttime air temperatures within the UHI. Generally speaking, the difference in temperature between the urban and surrounding rural area is more pronounced at night than in daytime. For example, in the United States, the temperature in urban areas tends to be warmer than

1386-407: Is greater downwind of cities, partially due to the UHI. Increases in heat within urban centers increases the length of growing seasons and decreases the occurrence of weak tornadoes . The UHI decreases air quality by increasing the production of pollutants such as ozone , and decreases water quality as warmer waters flow into area streams and put stress on their ecosystems . Not all cities have

1463-471: Is released into streams, rivers, ponds, and lakes. Additionally, increased urban water body temperatures lead to a decrease in biodiversity in the water. For example, in August 2001, rains over Cedar Rapids, Iowa led to a 10.5 °C (18.9 °F) rise in the nearby stream within one hour, resulting in a fish kill which affected an estimated 188 fish. Since the temperature of the rain was comparatively cool,

1540-537: Is the UHI Index of the surveyed area. The measure of Celsius-hours might be averaged over many days, but is specified as Celsius-hours per averaged day. The index was created to estimate the expected use of air conditioning and resulting greenhouse gas emissions in California. The index does not consider values of or differences in wind-speed, humidity, or solar influx , which might influence perceived temperature or

1617-441: Is the increased energy required for air conditioning and refrigeration in cities that are in comparatively hot climates. The heat island effect costs Los Angeles about US$ 100 million per year in energy (in the year 2000). Through the implementation of heat island reduction strategies, significant annual net energy savings have been calculated for northern locations such as Chicago, Salt Lake City, and Toronto. Every year in

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1694-575: Is usually done by government agencies, typically on the local level, but may occasionally be contracted out to a park conservancy , "friends of" group, or private sector company. Depending on size, budget, and land features, which varies considerably among individual parks, common features include playgrounds , gardens , hiking, running, fitness trails or paths, bridle paths , sports fields and courts, public restrooms, boat ramps, performance venues, or BBQ and picnic facilities. Park advocates claim that having parks near urban residents, including within

1771-547: The La Alameda de Hércules , in Seville , a promenaded public mall, urban garden and park built in 1574, within the historic center of Seville. The Városliget ( City Park ) in the City of Pest , what is today Budapest, Hungary , was a city property when afforestation started in the middle of the 18th century, from the 1790s with the clear aim to create a public park. Between 1799 and 1805 it

1848-614: The Pacific Place and its nearby escalator. Hong Kong Park captures the natural landscape in the busy and crowded business centre. Its main feature is Edward Youde Aviary which is Hong Kong's largest aviary while the Vantage Point is another great place to see the "bird exhibition". There is also a greenhouse (Forsgate Conservatory) which holds "plant exhibition" such as "Orchid Exhibition" temporarily. There are also many modern gardens, including Garden Plaza and tai chi Garden. To suit

1925-602: The Village of Yorkville Park in Toronto , which won an award from the American Society of Landscape Architects. Parks are sometimes made out of oddly shaped areas of land, much like the vacant lots that often become city neighborhood parks. Linked parks may form a greenbelt . There is a form of an urban park in the UK (officially called a "recreation ground", but commonly called a "rec" by

2002-502: The grey-headed flying fox ( Pteropus poliocephalus ) and the common house gecko ( Hemidactylus frenatus ). Grey-headed flying foxes, found in Melbourne, Australia , colonized urban habitats following the increase in temperatures there. Increased temperatures, causing warmer winter conditions, made the city more similar in climate to the more northerly wildland habitat of the species. With temperate climates, urban heat islands will extend

2079-423: The urban heat island ( UHI ) effect, that is, they are significantly warmer than surrounding rural areas . The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak, under block conditions, noticeably during the summer and winter . The main cause of the UHI effect is from the modification of land surfaces while waste heat generated by energy usage

2156-514: The use of lighter-colored surfaces and less absorptive building materials. These reflect more sunlight and absorb less heat. Climate change is not the cause of urban heat islands but it is causing more frequent and more intense heat waves which in turn amplify the urban heat island effect in cities. Compact, dense urban development may increase the urban heat island effect, leading to higher temperatures and increased exposure. A definition of urban heat island is: "The relative warmth of

2233-481: The U.S. 15% of energy goes towards the air conditioning of buildings in these urban heat islands. It was reported in 1998 that "the air conditioning demand has risen 10% within the last 40 years." Increases in air conditioning use also serve to worsen the effects of UHIs at night. While cooler nights are often a reprieve from heat waves during the day, the residual heat created by the use of air conditioning systems can lead to higher nighttime temperatures. According to

2310-517: The UHI effect within urban areas is the UHI Index created by the Californian EPA in 2015. It compares the temperature of a surveyed area and rural reference points upwind from the surveyed area, at a height of two meters above ground level. The difference in temperature in degrees Celsius is taken hourly and differences with an increased urban temperature compared to the reference points are summed up, creating an amount of degree-Celsius-hours, which

2387-451: The UHI. Heat islands can be affected by proximity to different types of land cover, so that proximity to barren land causes urban land to become hotter and proximity to vegetation makes it cooler. High levels of air pollution in urban areas can also increase the UHI, as many forms of pollution change the radiative properties of the atmosphere. UHI not only raises urban temperatures but also increases ozone concentrations because ozone

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2464-593: The UK, with around 2.6 billion visits to parks each year. Many parks are of cultural and historical interest, with 300 registered by Historic England as of national importance. Most public parks have been provided and run by local authorities over the past hundred and seventy years, but these authorities have no statutory duty to fund or maintain these public parks. In 2016 the Heritage Lottery Fund 's State of UK Public Parks reported that "92 per cent of park managers report their maintenance budgets have reduced in

2541-459: The United States and the world, though cow grazing did not end until the 1830s. Around the country, the predecessors to urban parks in the United States were generally rural cemeteries . The cemeteries were intended as civic institutions designed for public use. Before the widespread development of public parks, the rural cemetery provided a place for the general public to enjoy outdoor recreation amidst art and sculpture previously available only for

2618-827: The United States are Central Park in New York, Lincoln Park in Chicago, Mission Bay Park in San Diego. In the early 1900s, according to Cranz, U.S. cities built neighborhood parks with swimming pools, playgrounds and civic buildings, with the intention of Americanizing the immigrant residents. In the 1950s, when money became available after World War II , new parks continued to focus on both outdoor and indoor recreation with services, such as sports leagues using their ball fields and gymnasia. These smaller parks were built in residential neighborhoods, and tried to serve all residents with programs for seniors, adults, teens and children. Green space

2695-421: The built environment. Seasonal variability is less well understood than diurnal variability of the urban heat island temperature difference. Complex relationships between precipitation, vegetation, solar radiation, and surface materials in various local climate zones play interlocking roles that influence seasonal patterns of temperature variation in a particular urban heat island. One method to quantify

2772-497: The city can be another way of increasing albedo and decreasing the urban heat island effect. It is recommended to plant deciduous trees because they can provide many benefits such as more shade in the summer and not blocking warmth in winter. Trees are a necessary feature in combating most of the urban heat island effect because they reduce air temperatures by 10 °F (5.6 °C), and surface temperatures by up to 20–45 °F (11–25 °C). Another benefit of having trees in

2849-500: The city or area the effect is occurring. Additionally, covering rooftops with a reflective coating, has shown to be an effective measure to reduce solar heat gain. A study led by Oscar Brousse from University College London, which simulated the impact of various cooling measures in London found that rooftops, which were either painted white or had reflective coating, proved to be the most effective solution for reducing outdoor temperatures at

2926-490: The confines of a serpentine carriageway, put in place the essential elements of his much-imitated design for Birkenhead Park in Birkenhead . The latter commenced in 1843 with the help of public finance and deployed the ideas which Paxton had pioneered at Princes Park on a more expansive scale. Frederick Law Olmsted visited Birkenhead Park in 1850 and praised its qualities. Indeed, Paxton is widely credited as having been one of

3003-561: The day; materials commonly used in urban areas for pavement and roofs, such as concrete and asphalt , have significantly different thermal bulk properties (including heat capacity and thermal conductivity ) and surface radiative properties ( albedo and emissivity ) than the surrounding rural areas. This causes a change in the energy budget of the urban area, often leading to higher temperatures than surrounding rural areas. Pavements , parking lots , roads or, more generally speaking transport infrastructure , contribute significantly to

3080-405: The daytime, particularly when the skies are cloudless, urban surfaces are warmed by the absorption of solar radiation . Surfaces in the urban areas tend to warm faster than those of the surrounding rural areas. By virtue of their high heat capacities , urban surfaces act as a reservoir of heat energy. For example, concrete can hold roughly 2,000 times as much heat as an equivalent volume of air. As

3157-625: The deaths could be attributed to the hot pavement of the city. Similar events have been documented across the American Midwest, as well as Oregon and California. Rapid temperature changes can be stressful to aquatic ecosystems. With the temperature of the nearby buildings sometimes reaching a difference of over 50 °F (28 °C) from the near-surface air temperature, precipitation warms rapidly, and run-off into nearby streams, lakes and rivers (or other bodies of water) to provide excessive thermal pollution . The increase in thermal pollution has

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3234-449: The designed landscape as a setting for the suburban domicile (an idea pioneered by John Nash at Regent's Park in London) and re-fashioned it for the provincial town in a most original way. Nash's remodelling of St James's Park from 1827 and the sequence of processional routes he created to link The Mall with Regent's Park completely transformed the appearance of London's West End . With

3311-632: The effect on temperature, UHIs can produce secondary effects on local meteorology, including the altering of local wind patterns, the development of clouds and fog , the humidity , and the rates of precipitation. The extra heat provided by the UHI leads to greater upward motion, which can induce additional shower and thunderstorm activity. In addition, the UHI creates during the day a local low pressure area where relatively moist air from its rural surroundings converges, possibly leading to more favorable conditions for cloud formation. Rainfall rates downwind of cities are increased between 48% and 116%. Partly as

3388-494: The establishment of Princes Park in 1842, Joseph Paxton did something similar for the benefit of a provincial town, albeit one of international stature by virtue of its flourishing mercantile sector. Liverpool had a burgeoning presence in global maritime trade before 1800, and during the Victorian era its wealth rivalled that of London itself. The form and layout of Paxton's ornamental grounds, structured about an informal lake within

3465-777: The first comprehensive numerical treatment to predict the effects of the urban heat island (UHI) in 1969. The heat island effect was found to be the net result of several competing physical processes. In general, reduced evaporation in the city center and the thermal properties of the city building and paving materials are the dominant parameters. Modern simulation environments include ENVI-met , which simulates all interactions between building and ground surfaces, plants and ambient air. There are several causes of an urban heat island (UHI) related to common urban design aspects. For example, dark surfaces absorb significantly more solar radiation , which causes urban concentrations of roads and buildings to heat more than suburban and rural areas during

3542-485: The flow of the water in ways that can mitigate UHI effect. One way is using a stormwater management technique called pervious pavement system (PPS). This technique has been used in over 30 countries and found to be successful in stormwater management and UHI mitigation. The PPS allows water to flow through the pavement allowing for the water to be absorbed causing the area to be cooled by evaporation. Green parking lots use vegetation and surfaces other than asphalt to limit

3619-779: The form of walking, running, horse riding, mountain biking, snowshoeing, or cross-country skiing; or sedentary activity such as observing nature, bird watching, painting, photography, or picnicking. Limiting park or open space use to passive recreation over all or a portion of the park's area eliminates or reduces the burden of managing active recreation facilities and developed infrastructure. Many ski resorts combine active recreation facilities (ski lifts, gondolas, terrain parks, downhill runs, and lodges) with passive recreation facilities (cross-country ski trails). Many smaller neighborhood parks are receiving increased attention and valuation as significant community assets and places of refuge in heavily populated urban areas. Neighborhood groups around

3696-535: The former location of the Victoria Barracks , built between 1867 and 1910, the barracks were handed to the government in 1979. Glenealy Junior School occupied part of this site up until 1988. After the school vacated the site, the area was turned into the present park. Hong Kong Park was officially opened on 23 May 1991 by Sir David Wilson , the Governor of Hong Kong at that time. It covers an area of 8 hectares and

3773-567: The growing season, therefore altering breeding strategies of inhabiting species. This can be best observed in the effects that urban heat islands have on water temperature (see effects on water bodies ). Urban heat islands caused by cities have altered the natural selection process. Selective pressures like temporal variation in food, predation and water are relaxed causing a new set of selective forces to roll out. For example, within urban habitats, insects are more abundant than in rural areas. Insects are ectotherms . This means that they depend on

3850-763: The higher temperatures in UHIs can quicken the production of ozone . Ozone at surface level is considered to be a harmful pollutant. Studies suggest that increased temperatures in UHIs can increase polluted days but also note that other factors (e.g. air pressure , cloud cover , wind speed ) can also have an effect on pollution. Studies from Hong Kong have found that areas of the city with poorer outdoor urban air ventilation tended to have stronger urban heat island effects and had significantly higher all-cause mortality compared to areas with better ventilation. Another study employing advanced statistical methods in Babol city, Iran, revealed

3927-463: The jet stream. UHIs have the potential to directly influence the health and welfare of urban residents. As UHIs are characterized by increased temperature, they can potentially increase the magnitude and duration of heat waves within cities. The number of individuals exposed to extreme temperatures is increased by the UHI-induced warming. The nighttime effect of UHIs can be particularly harmful during

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4004-478: The lack of a shared framework for making such comparisons. Stormwater management is another option to help mitigate the effect of the urban heat island. Stormwater management is the controlling the water produced by the storm in a way that protects property and infrastructure. Urban infrastructure like streets, sidewalks, and parking lots do not allow for water to penetrate into the earth's surface causing water to flood. By using stormwater management, you can control

4081-525: The large amount of open space and natural habitat in the former pleasure grounds, they now serve as important wildlife refuges, and often provide the only opportunity for urban residents to hike or picnic in a semi-wild area. However, city managers or politicians can target these parks as sources of free land for other uses. Partly for this reason, some of these large parks have "friends of X park" advisory boards that help protect and maintain their semi-wild nature. There are around estimated 27,000 public parks in

4158-567: The need to provide substantial space to congregate, typically involves intensive management, maintenance, and high costs. Passive recreation, also called "low-intensity recreation" is that which emphasizes the open-space aspect of a park and allows for the preservation of natural habitat. It usually involves a low level of development, such as rustic picnic areas, benches, and trails. Passive recreation typically requires little management and can be provided at very low costs. Some open space managers provide nothing other than trails for physical activity in

4235-417: The operation of air conditioners. If a city or town has a good system of taking weather observations the UHI can be measured directly. An alternative is to use a complex simulation of the location to calculate the UHI, or to use an approximate empirical method. Such models allow the UHI to be included in estimates of future temperatures rises within cities due to climate change. Leonard O. Myrup published

4312-617: The other sources of the problem, replacing dark roofing requires the least amount of investment for the most immediate return. A cool roof made from a reflective material such as vinyl reflects at least 75 percent of the sun's rays, and emit at least 70 percent of the solar radiation absorbed by the building envelope. Asphalt built-up roofs (BUR), by comparison, reflect 6 percent to 26 percent of solar radiation. Using light-coloured concrete has proven effective in reflecting up to 50% more light than asphalt and reducing ambient temperature. A low albedo value, characteristic of black asphalt, absorbs

4389-671: The overall albedo of the city. Concentric expansion of cities is unfavourable in terms of the urban heat island phenomenon. It is recommended to plan the development of cities in strips, consistent with the hydrographic network, taking into account green areas with various plant species. In this way, it was planned to build urban settlements stretching over large areas, e.g. Kielce , Szczecin and Gdynia in Poland, Copenhagen in Denmark and Hamburg , Berlin and Kiel in Germany. Planting trees around

4466-404: The park was built was purchased by Richard Vaughan Yates, an iron merchant and philanthropist, in 1841 for £50,000. The creation of Princes Park showed great foresight and introduced a number of highly influential ideas. First and foremost was the provision of open space for the benefit of townspeople and local residents within an area that was being rapidly built up. Secondly it took the concept of

4543-420: The past three years and 95 per cent expect their funding will continue to reduce". Parks can be divided into active and passive recreation areas. Active recreation is that which has an urban character and requires intensive development. It often involves cooperative or team activity, including playgrounds , ball fields, swimming pools, gymnasiums, and skateparks . Active recreation such as team sports, due to

4620-436: The pedestrian level, outperforming solar panels, green roofs, and tree cover. The study simulated the impact of various cooling measures in London during a 2018 heatwave, finding that the so-called cool roofs could reduce average outdoor temperatures by 1.2 °C, and up to 2 °C in certain areas. In comparison, additional tree cover reduced temperatures by 0.3 °C and solar panels by 0.5° C. Relative to remedying

4697-596: The potential to increase water temperature by 20 to 30 °F (11 to 17 °C). This increase causes the fish species inhabiting the body of water to undergo thermal stress and shock due to the rapid change in temperature of their habitat. Permeable pavements may reduce these effects by percolating water through the pavement into subsurface storage areas where it can be dissipated through absorption and evaporation. Species that are good at colonizing can use conditions provided by urban heat islands to thrive in regions outside of their normal range. Examples of this include

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4774-480: The price of labor and equipment in that market, which is typically lower in more developed markets where there is more experience designing and installing green roofs. The individualized context of each green roof presents a challenge for making broad comparisons and assessments, and focusing only on monetary costs may leave out the social, environmental, and public health benefits green roofs provide. Global comparisons of green roof performance are further challenged by

4851-452: The principal influences on Olmsted and Calvert's design for New York's Central Park of 1857. Another early public park, the Peel Park, Salford , England, opened on 22 August 1846. Boston Common was purchased for public use grazing cows and as a military parade ground and dump in 1634. It first started to get recreational elements in 1728, arguably making it the first municipal park in

4928-436: The public.) and some EU states that have mostly recreation grounds for kids to play within a park, but may also have a duck pond, large grassy zones not meant exclusively for sports, many trees, and several bushy places. When it occurs as a separate facility on its own, without any parkland, at a street corner or by a shop, the play facility is called a playground . Urban heat island Urban areas usually experience

5005-435: The rest of the U.S., largely in part due to UHIs. Heat illnesses can also be compounded when combined with air pollution which is common in many urban areas. Heat exposure can have adverse effects on mental health. Increases in temperature can contribute to increased aggression, as well as more cases of domestic violence and substance abuse. Greater heat can also negatively impact school performance and education. According to

5082-561: The shade and evaporative cooling effect of trees. Other causes of a UHI are due to geometric effects. The tall buildings within many urban areas provide multiple surfaces for the reflection and absorption of sunlight, increasing the efficiency with which urban areas are heated. This is called the " urban canyon effect ". Another effect of buildings is the blocking of wind, which also inhibits cooling by convection and prevents pollutants from dissipating. Waste heat from automobiles, air conditioning, industry, and other sources also contributes to

5159-664: The sport-lovers, a sport centre and a squash centre were also built in Hong Kong Park. Public park An urban park or metropolitan park , also known as a city park , municipal park (North America), public park , public open space , or municipal gardens ( UK ), is a park or botanical garden in cities , densely populated suburbia and other incorporated places that offers green space and places for recreation to residents and visitors. Urban parks are generally landscaped by design, instead of lands left in their natural state. The design, operation and maintenance

5236-430: The surrounding area by about 1-7 °F (0.6-4 °C) during the daytime, and about 2-5 °F (1-3 °C) warmer at night. However, the difference is more pronounced during the day in arid climates such as those in southeastern China and Taiwan. Studies have shown that diurnal variability is impacted by several factors including local climate and weather, seasonality, humidity, vegetation, surfaces, and materials in

5313-406: The surrounding suburban or rural areas can be as much as 5 °C (9.0 °F). Nearly 40 percent of that increase is due to the prevalence of dark roofs, with the remainder coming from dark-coloured pavement and the declining presence of vegetation. The heat island effect can be counteracted slightly by using white or reflective materials to build houses, roofs, pavements, and roads, thus increasing

5390-613: The temperature of the environment to control their body temperature, making the warmer climates of the city perfect for their ability to thrive. A study done in Raleigh, North Carolina conducted on Parthenolecanium quercifex (oak scales), showed that this particular species preferred warmer climates and were therefore found in higher abundance in urban habitats than on oak trees in rural habitats. Over time spent living in urban habitats, they have adapted to thrive in warmer climates than in cooler ones. Another consequence of urban heat islands

5467-492: The urban heat island effect. For example, pavement infrastructure is a main contributor to urban heat during summer afternoons in Phoenix , United States. Another major reason is the lack of evapotranspiration (for example, through lack of vegetation) in urban areas. The U.S. Forest Service found in 2018 that cities in the United States are losing 36 million trees each year. With a decreased amount of vegetation, cities also lose

5544-414: The warm weather months and the plants cool the surrounding environment. Plants can improve air quality as they absorb carbon dioxide and concomitantly produce oxygen. Green roofs can also have positive impacts on stormwater management and energy consumption. Cost can be a barrier to implementing a green roof. Several factors influence the cost of a green roof, including design and soil depth, location, and

5621-485: The wealthy. In The Politics of Park Design: A History of Urban Parks in America, (Cambridge, Massachusetts: MIT Press, 1982), Professor Galen Cranz identifies four phases of park design in the U.S. In the late 19th century, city governments purchased large tracts of land on the outskirts of cities to form "pleasure grounds": semi-open, charmingly landscaped areas whose primary purpose was to allow city residents, especially

5698-484: The workers, to relax in nature. As time passed and the urban area grew around the parks, land in these parks was used for other purposes, such as zoos, golf courses and museums. These parks continue to draw visitors from around the region and are considered regional parks , because they require a higher level of management than smaller local parks. According to the Trust for Public Land , the three most visited municipal parks in

5775-524: The world are joining together to support local parks that have suffered from urban decay and government neglect. A linear park is a park that has a much greater length than width. A typical example of a linear park is a section of a former railway that has been converted into a park called a rail trail or greenway (i.e. the tracks removed, vegetation allowed to grow back). Some examples of linear parks in North America include New York's High Line and

5852-525: Was of secondary importance. As urban land prices climbed, new urban parks in the 1960s and after have been mainly pocket parks . One example of a pocket park is Chess Park in Glendale, California. The American Society of Landscape Architects gave this park a General Design Award of Honor in 2006. These small parks provide greenery, a place to sit outdoors, and often a playground for children. All four types of park continue to exist in urban areas. Because of

5929-537: Was rented out to the Batthyány family to carry out such a project but the city had eventually taken back control and in 1813 announced a design competition to finally finish the park; works started in 1816. An early purpose-built public park, although financed privately, was Princes Park in the Liverpool suburb of Toxteth . This was laid out to the designs of Joseph Paxton from 1842 and opened in 1843. The land on which

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