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-The simplified topographic map of Ankara and its surroundings (a) and the city of Ankara-the area of investigation (b).
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Ankara is the second largest city in Turkey after Istanbul, and the rate of population increase and urbanization are quite high. In this study, the effects of urbanization on temperature variation due to urbanization in Ankara were investigated. The intensities of urban heat island (UHI) for long and short term were analyzed. Analysis of both long-...
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Citations
... Such an explosion in urban population has been causing urban sprawl and expansion with heavy construction activities and pressures on natural areas. Newly or previously constructed urban sites have high adverse effects on HBCCs due to heat island effects, lack of green and blue areas, etc., compared to their rural counterparts (Mayer 1993;Unger 1999;Çiçek and Doğan 2005;Charalampopoulos et al. 2013;Çağlak 2017;Toy et al. 2021;Bal and Matzarakis 2022). The city of Adana, which is an agriculture, trade, and cultural centre for the East Mediterranean Region of Turkey, therefore has faced all the aforementioned processes and is already under the impact of extreme heat stress in most of the year. ...
Human bioclimatic comfort (HBC) is an important subject of climatology in the field of physical geography. Human bioclimatic comfort (HBC) is the feeling of satisfied and comfortable within the ambient atmospheric thermal environment. Earth climate system has been exposed to changes from the beginning, but since 19th century human – induced factors have contributed to these changes. HBC is the combined effect of atmospheric conditions and affected by all the changes in them. Turkey is among the countries in Mediterranean region, expected to develop higher vulnerabilities to the (bio) climate hazards. Therefore, a Mediterranean city in the south of the country, Adana, was chosen as the study area. HBC assessment was made for the past (1961 – 1990), present (1991 – 2022), near (2030 – 2060) and distant future (2070 – 2100) using hourly - data from the official meteorology station between 1961 and 2022, daily data of the climate model scenarios (Representative Concentration Pathway - RCP4.5 and RCP8.5) and Physiological Equivalent Temperature (PET) index, the Rayman model and Geographic Information Systems in the spatial distribution of HBC conditions. The analysis showed that the prevalence of "cold" and "cool" stresses has decreased while that of "hot" and "very hot" stresses has increased from the past to the present in Adana. It is predicted that present conditions will continue in the near and distant future, all comfort ranges will increase to the following warm range and the ideal period for HBC conditions will be the winter season. In order to reduce the adverse HBC conditions in cities due to climate change by creating climate resilient, sustainable and healthy cities, urban design and planning principles should be followed from a geographical point of view.
... Numerous studies reveal that the climate characteristics of cities have changed negatively depending upon the decrease in green areas and soil-covered surfaces in cities (Barış 2005;Çiçek and Doğan 2005;Şimşek and Şengezer 2012;White and Kimmi 2015;. These unfavourable conditions cause cities to have more uncomfortable conditions than the surrounding rural areas. ...
Rapid human population increase in cities following industrial revolution caused irreversible changes in the physical structure of urban areas by increasing the rate of built-up surface to an unprecedented level. Both the altered physical environment and dense anthropogenic activities in the cities affected also atmospheric environment and climate characteristics in the cities. Today, more than half of the world population lives in cities while nearly 70% is estimated to live in cities by 2050. Turkey’s industrialisation and urbanisation process followed a similar way and cities faced a rapid and distorted urbanisation after especially 1950s. Today, over 80% of Turkish population lives in urban areas. Therefore, dwellers in Turkish cities are exposed to unfavourable bioclimatic conditions both due to existent and future urban climatic characteristics and the density of anthropogenic activities. This study is dealt with the effect of urbanisation on bioclimatic comfort conditions in Uşak, a medium-sized Turkish city, between the Aegean and the Central Anatolia regions in the western part of the country, where Mediterranean transitional climate characteristics are dominant and population increases. In the study, 14-year hourly data obtained from two meteorology stations located in urban and rural areas were used to calculate bioclimatic comfort values using PET (Physiological Equivalent Temperature) index and RayMan software. As a result of the study, the urban area was found to be warmer than the rural (2.4 °C, 1.6 °C and 2.2 °C on the average, maximum and minimum PET values). Urban area is exposed to 5.9% and 28.0% more heat stress than rural throughout the year and during the summer period, respectively. As a result of the study, suggestions were made to make landscape designs that take into account the physical geographical conditions for current and future urbanisation movements in order to optimise bioclimatic comfort conditions in cities. In this context, in order to improve the bioclimatic comfort conditions in the city, expanding the areas covered with soil and plants, creating artificial water areas, implementing roof garden applications, vertical and horizontal planting works, and creating wind corridors are some of the suggestions. It is thought that the determined suggestions will contribute to the slowing down of climate change on a global scale, as well as providing bioclimatic comfort in cities.
... In the "Climate Change Action Plan" published by Ankara Metropolitan Municipality, strategies and action plans have been developed to reduce the urban heat island effect. The importance of measuring and documenting the impact of smaller-scale urban parks on reducing the urban heat island has been emphasized in the strategies developed for the city [51][52][53]. ...
The rapid urbanization of cities has led to a radical change in the use of land in cities with the accompanying climate change. It has formed urban heat islands, which have begun to be characterized by climatic conditions such as temperature, precipitation, humidity and wind that differ from the surroundings of cities. It is observed that the heat island effect is felt more intensively day by day, especially in large cities such as Ankara, where urbanization is increasing. It is possible to determine and analyze the urban heat island effect using satellite technologies. Google Earth Engine (GEE) is an online platform that enables remote sensing users to efficiently perform big data analysis without increasing the demand for local computing resources. In this study, NDVI (Normalized Difference Vegetation Index) and LST (Land Surface Temperature) spectral indices were analyzed using Google Earth Engine, remote sensing and GIS techniques in four important parks with different sizes and plant diversity located in the urban area of Ankara. The NDVI and LST results were then analyzed with zonal statistics. Although studies have shown that urban parks create a temperature change effect of about 1ºC, it has been observed that the temperature difference is about 3 °C in this study. These results show that the urban heat island effect is increasing in Ankara province, where the effects of climate change are seen rapidly.
... Such an approach interlaces with the growing need to consider outdoor conditions over indoor conditions, as suggested by several studies [38,39,[51][52][53][54][55]. Limited work has been undertaken that could otherwise inform interdisciplinary approaches towards human health with regard to heat risk management in Ankara [21,40,44,[56][57][58][59] The application of extreme heat events was decided according to the percentile-based descriptions of locally adapted CCDIs, i.e., cool days, cool nights, warm days, and warm nights [44]. The adaptation of CCDIs for Ankara was operated regarding yearly T a data of Ankara between 2008 and 2020 through the R-based script RClimDex. ...
The necessity of exploring the relationship between sleep quality and the thermal environment has amplified regarding increasing heat stress risk on the human body due to climate change, particularly in vulnerable uninsulated buildings in Ankara. Within this scope, this study investigated occupants' sleep quality and human thermal comfort in insulated and uninsulated buildings under three local extreme heat event thresholds: (1) typical summer days (TSD 25), (2) very hot days (VHD 33), and lastly, (3) heat wave events (HWE 31). Within a two-tiered approach to thermal comfort evaluations, the human thermal comfort of occupants was identified through the calculation of physiologically equivalent temperature (PET) from the climatic data of local meteorological stations. The psychological thermal comfort and sleep quality of participants were evaluated by questionnaires during each heat event. The results of this study demonstrated that the physiological thermal load of the participants was highest during VHD 33 s, given that both outdoor and indoor PET values presented their highest values within VHD 33 events. Furthermore, the outdoor PET values reached extreme heat stress based on physiological stress grades with 43.5 • C, which indicated the exacerbated vulnerability of Ankara during extreme heat events. The PET values were consistently higher in uninsulated buildings than in insulated buildings. Also, most of the mean psychological thermal comfort votes and sleep quality votes were better in uninsulated buildings than in insulated ones during TSD 25 s and HWE 31 s, while it was the opposite within extreme conditions of VHD 33 s. The outputs of this study contribute to interdisciplinary efforts to attenuate the existing and impending risks of climate change on human life by defining the influence of increasing outdoor heat stress on indoor spaces, thermal comfort, and the sleep quality of occupants.
... As a result of these changes, urban areas have different climatic conditions from the rural and sub-urban areas around them. In many studies in the world and in Turkey, it has been explained that adverse climatic conditions are observed in urban areas due to the destruction of natural surfaces and the decrease in the amount of green areas [3][4][5][6][7][8][9][10][11]. ...
Urban settlements, one of the most important developments in the history of humanity, expanded due to the migration movements from rural to urban areas and turned into dense and high-built settlements. This situation has caused urban areas to have different climatic conditions from the suburban and rural areas around them. Bioclimatic comfort is the state of people to feel comfortable, happy and fit in the atmospheric environment they are in. Uncomfortable conditions cause much negativity such as decrease in people's work efficiency, health conditions and increase in energy consumption. Amasya is a small Anatolian city in the Central Black Sea Region of the Black Sea Region, where industrialization has not developed. In this study, hourly data of the year 2021 of two meteorology stations, which are considered as urban and suburban, were used in order to examine the effects of urban areas on bioclimatic comfort conditions in Amasya. As a method, the PET (Physiological Equivalent Temperature) index obtained from the RayMan model, which calculates many factors together, was used. As a result of the study, suburban is 2.1 ˚C cooler than urban at the general PET average; 3.4˚C cooler at the maximum average and 2.8˚C cooler at the minimum average. The urban area is exposed to heat stress by 8.1% more throughout the year than the suburban area. In order to reduce the negative bioclimatic comfort conditions of cities and for sustainable urbanization, it is necessary to make urban design and planning that takes into account human, ecological and physical conditions.
... Numerous studies reveal that the climate characteristics of cities have changed negatively depending upon the decrease in green areas and soil-covered surfaces in cities (Barış 2005;Çiçek and Doğan 2005;Şimşek and Şengezer 2012;White and Kimmi 2015;. These unfavourable conditions cause cities to have more uncomfortable conditions than the surrounding rural areas. ...
... Ankara is located at Ankara plain -formed by Ankara Stream and its branches [1]-and at an altitude of 850 meters. Ankara plain is defined by a parallel ridge of mountains that extend from west to east [2] and is closed at the northern, southern and eastern edges [3]. ...
This paper aims to provide a critical overview of the management of Ankara’s streams in the historical context of the city’s urbanization process and focuses on one particular example Bentderesi (Bent stream). Prior to Ankara’s declaration as a capital city and during the early periods of the young Republic of Turkey, the streams and creeks of the city were the significant destinations for public recreation and they were also used for freshwater supply and fishing. However, ironically, these streams had caused the most damage to their surroundings due to floods several times. For instance, in 1957, the flood along the Hatip Stream affected many areas along its bed, including Mamak, Saimekadın, Gülveren, Bentderesi, Dışkapı, Kazıkiçi vegetable gardens and Akköprü which led to many casualties and serious physical damage. At the same time, some of these streams had been highly polluted and literally had become open sewers. These all led to a drastic change in the urban landscape of Ankara; many streams and creeks were channelized and paved over. Bentderesi was one of them. Actually, Bentderesi (meaning barraged creek) is part of the Hatip Stream. It takes this name near the old settlement area, the Ankara Citadel. According to the literature, Bentderesi name comes from the dam structures on the creek built in Roman times. Unfortunately, the ruins had not been protected or conserved and are invisible today. Currently, vehicle traffic flows along “Bentderesi Street” which was built overtop the channelized river. Although the first plans for the newly established capital made use of Bentderesi and its surroundings as green spaces for leisure and ecological benefits, it became a slum area after it had been channelized. Today, Ankara is facing with water supply problems and the global climate change scenarios do not seem promising as well. Furthermore, there has been a rise in floods occurring in the urban fabric due to the increased impermeable paved surfaces overtop the creek and streams and their beds. Restoring and re-discovering the lost stream landscapes of the city would be a major, but at the same time an incredibly exciting challenge for Ankara and its urban landscape in terms of both ecological and social sustainability. In this regard, this paper will address to the conflicts between policies and the need for conservation of water surfaces of Ankara within the specific example of Bentderesi.
... According to the Köppen Classification, Ankara has a hot-summer Mediterranean climate (CSA) bordering on a hot-summer Mediterranean continental climate (DSA). There is a strong urban heat island effect in Ankara (Çiçek & Doğan, 2006) and a lack of green spaces in Ankara and most of the existing parks consist of grass mainly. The municipality is already implementing NBS actions, as one of its fundamental visions is to create and use environmentally-friendly systems to ensure a good future for the next generations. ...
Beside environmental and economic impact of NBS, an alternative valuation scale based on quality of life was also developed as part of the Nature4Cities project.
This scale provides additional information on the possible benefits of NBS on several dimensions of quality of life (social, physical and environmental). Understanding NBS and NBS perceived benefits would be a major step in promoting existing NBS, as well as key to success for new NBS projects.
Environmental quality of life is a multidimensional concept and considers the benefits of environment on physical, psychological and social dimensions (WHO, 1998), as well as multiple aspects of interactions between individuals and their environment (thermal comfort, noise, air quality, ambience, etc.).
... For topographical point of view, Ankara is the deepest point in the valley surrounded by mountains. Because of the temperature inversion in this area, decreasing boundary layer depth and also anthropogenic heat cause to have intense urban heat island effect on Ankara in winter season (Çiçek & Doğan, 2006). Advection and radiation fogs are likely to be seen on this area as temperature inversion occurs frequently in winter season. ...
... For instance Ezber et al. [10] used statistical and numerical modeling tools to investigate the climatic effects of urbanization in Istanbul using the data from 6 meteorological stations and found a significant warming trend in the atmosphere over the urbanized areas. Likewise, Çiçek and Doğan [11] investigated the effects of urbanization on temperature variation in Ankara using the data from 7 meteorological stations and concluded that there has been a significant increase with the UHI intensity in winters. However, the data collected at meteorological stations in Turkey may not represent non-urban weather conditions, since most of the stations are located or remained in between settlements due to the rapid urbanization. ...
The distinct characteristics of urban and non-urban land cover usually results with a positive difference in surface temperatures and is referred to as the urban heat island (UHI) phenomenon. This paper assesses the spatio-temporal formation of UHI and land surface temperatures (LSTs) in Izmir, Turkey, situated in a Mediterranean climate region. LSTs were obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua and Terra over the period 2000-2015. UHI intensity was examined using the temperature differences between urban and non-urban areas and non-parametric Mann-Kendall (M-K) test to identify trends in LSTs and UHI intensity. The results indicate that daytime UHI is higher at Izmir with a seasonal variation. M-K test of LSTs shows increasing trends in nighttime temperatures for both urban and non-urban areas especially for winter and spring.
