Urban Heat Island Kota Surabaya

Perkembangan jumlah dan aktivitas penduduk perkotaan diyakini telah berpengaruh terhadap degradasi lingkungan fisik perkotaan, ditandai dengan menurunnya kualitas udara dan meningkatnya urban heat islands (UHI). Hasil beberapa menelitian menunjukan pola spasial suhu permukaan di perkotaan menunjukan terbentuknya UHI di daerah pusat kota dan makin ke arah pinggiran kota cenderung semakin menurun. Peningkatan suhu udara perkotaan tersebut diduga berkontribusi pula terhadap fenomena pemanasan global dan Perubahan iklim yang sedang terjadi. Melalui pengolahan dan interpretasi citra Landsat yang diverifikasi dengan survey lapangan pada 40 lokasi dengan stratified random sampling, penelitian ini ingin mengungkapkan pola spasial UHI dan kecenderungan arah Perubahannya di Kota Surabaya pada periode 1994-2000 dan 2000 – 2011, dengan mengkaitkannya dengan variabel tutupan lahan, kerapatan vegetasi dan kerapatan bangunan. Hasis analisis spasial menunjukkan bahwa UHI di Kota Surabaya pada tahun 1994, 2000 dan 2011 terbentuk di pusat kota dan cenderung semakin bertambah luas arealnya. Peningkatan UHI di Kota Surabaya berbanding lurus dengan kerapatan bangunan, dan berbanding terbalik dengan kerapatan vegetasi. Perubahan UHI pada periode 1994-2000 terjadi dari arah pusat kota ke arah utara dan selatan kota, sedangkan pada periode 2000-2011 cenderung terjadi dari pusat kota ke barat dan timur kota. Kata Kunci: Citra Landsat, Kerapatan Bangunan, Kerapatan Vegetasi, Kota Surabaya, Urban Heat Island

Urban Heat Islands and their Associated Impacts on Health

Towns and cities generally exhibit higher temperatures than rural areas for a number of reasons, including the effect that urban materials have on the natural balance of incoming and outgoing energy at the surface level, the shape and geometry of buildings, and the impact of anthropogenic heating. This localized heating means that towns and cities are often described as urban heat islands (UHIs). Urbanized areas modify local temperatures, but also other meteorological variables such as wind speed and direction and rainfall patterns. The magnitude of the UHI for a given town or city tends to scale with the size of population, although smaller towns of just thousands of inhabitants can have an appreciable UHI effect. The UHI “intensity” (the difference in temperature between a city center and a rural reference point outside the city) is on the order of a few degrees Celsius on average, but can peak at as much as 10°C in larger cities, given the right conditions. UHIs tend to be enhanced during heatwaves, when there is lots of sunshine and a lack of wind to provide ventilation and disperse the warm air. The UHI is most pronounced at night, when rural areas tend to be cooler than cities and urban materials radiate the energy they have stored during the day into the local atmosphere. As well as affecting local weather patterns and interacting with local air pollution, the UHI can directly affect health through heat exposure, which can exacerbate minor illnesses, affect occupational performance, or increase the risk of hospitalization and even death. Urban populations can face serious risks to health during heatwaves whereby the heat associated with the UHI contributes additional warming. Heat-related health risks are likely to increase in future against a background of climate change and increasing urbanization throughout much of the world. However, there are ways to reduce urban temperatures and avoid some of the health impacts of the UHI through behavioral changes, modification of buildings, or by urban scale interventions. It is important to understand the physical properties of the UHI and its impact on health to evaluate the potential for interventions to reduce heat-related impacts

Identifikasi Urban Heat Island di Kota Surakarta

Tujuan dari penelitian ini adalah mengetahui pola suhu permukaan dan suhu udara di Kota Surakarta pada tahun 2015, menganalisis fenomena Urban Heat Island (UHI) di Kota Surakarta, dan menganalisis strategi untuk mengurangi fenomena UHI. Data yang digunakan berupa citra Landsat 8 dan pengukuran suhu udara di lapangan. Berdasarkan penelitian diperoleh bahwa pola suhu permukaan di Kota Surakarta cenderung mengelompok di tengah kota khususnya di Kecamatan Pasar Kliwon. Peta suhu permukaan dan udara memiliki 5 kategori suhu. Kategori suhu paling tinggi memiliki rentang 31,5 - 34,7°C. Perbedaan suhu yang terjadi antara daerah kota dan sekitarnya menunjukan bahwa di Kota Surakarta memiliki potensi untuk terjadi fenomena UHI. Strategi yang tepat untuk mengurangi fenomena UHI terjadi salah satunya adalah dengan menata penggunaan lahan yang ada di daerah kota

The Urban Heat Island Effect in Nevada

This fact sheet explores the temperature difference between Nevada cities and their undeveloped surrounding areas using reports by the Urban Land Institute, Climate Central, National Public Radio (NPR), and various governmental organizations. We investigate what “urban heat islands” are, their effects, the correlation between heat and income, and factors that contribute to rising temperatures in Las Vegas, North Las Vegas, Henderson, and Reno

Atmospheric impacts on daytime urban heat island

Daytime urban heat island effects can be weak compared to night time and even reversed (as in the case of cool islands, where urban locations display lower temperatures than at a rural site), mostly due to shading effects from buildings, vegetation, and other possible obstructions. The study of the relationship between the sky-view factor, an indicator of urban geometry in terms of sky openness, and urban heat island intensity generally focus on night time periods; only a few report on the daytime effect of the SVF. Such effect will also vary according to background atmospheric conditions of the period of measurements. This article is a commentary on a recent publication by the authors on a study of diurnal intra-urban temperature differences in a location with Koeppen’s Cfb climate

Designing out the urban heat island effect

As the global population reaches an all time high and shows no sign of slowing, and the urban population outnumbers the rural population for the first time in human history, the social, economic and environmental issues faced by those living in urban centres become increasing relevant. The urban heat island effect is a phenomenon witnessed in cities worldwide which sees the ambient air temperatures in cities be significantly higher when compared to temperatures in the rural surroundings. A number of characteristics of cities contribute to the creation of an urban heat island: the removal of vegetation to construct buildings and road; the ability of materials such as concrete, asphalt, steel and brick to absorb, store and release heat; the energy used by a building’s services including heating, air conditioning and ventilation; vehicular movement through a city; and general lack of green spaces. Essentially, urban heat islands are caused by the land use change from natural environment to built environment

Industrial heat island: a case study of Angul-Talcher region in India

Most of the urban heat island (UHI) studies are carried out in densely populated cities but core industrial areas are also potential sites of heat island effect despite having a comparatively lower population. In the present study, heat island assessment has been carried out for Angul-Talcher industrial area (ATIA) which is one of the oldest industrial areas of India and is still undergoing a transformation to accommodate more industries and mining operations. As the major contributors towards influencing local meteorology were expected to be industrial (and mining) activities, the heat island was studied as "industrial heat island" (IHI) rather than urban heat island. Industrial and mining sites were the most frequent nighttime canopy-layer heat island intensity (HIN) hotspots due to anthropogenic heat of associated industrial processes as well as built structures. During the daytime, croplands experienced the most frequent canopy-layer HIN hotspots which could be attributed to low moisture of the soils during the non-farming period of the field campaign. Hourly maximum atmospheric heat island intensities were observed in the range of 7-9 degrees C. Monthly maximum HINs ranged from 2.97 to 4.04 degrees C while 3-month mean HINs varied from 1.45 to 2.74 degrees C. Amongst different land use/land cover classes, the highest mean canopy-layer heat island intensity for the entire 3-month-long duration of field campaign during nighttime was assessed at the mining sites (3-month mean 2.74 degrees C) followed in decreasing order by the industrial sites (2.52 degrees C), rural and urban settlements (2.13 degrees C), and croplands (2.06 degrees C). Corresponding daytime canopy-layer heat island intensity was highest for the croplands (2.07 degrees C) followed in decreasing order by the mining sites (1.70 degrees C), rural and urban settlements (1.68 degrees C), and industry (1.45 degrees C)

Studi Pulau Bahang (Heat Island) di Kompleks Universitas Gadjah Mada

Fenomena kenaikan suhu di kota-kota di Indonesia sebagian besar disebabkan oleh Perubahan penutup lahan, kepadatan bangunan dan gas buang kendaraan bermotor. Penelitian ini bertujuan: 1) Mengkaji karakteristik pulau bahang (heat island), 2) Mengkaji sebaran pulau bahang (heat island) pada daerah penelitian. Metode survei pengukuran suhu dilakukan dengan cara purposive sampling sebanyak 30 sampel. Sampel dibagi menjadi 2 bagian, masing-masing sejumlah 15 sampel yang berbasis pada lahan terbangun dan lahan bervegetasi. Parameter penggunaan lahan bervegetasi dan lahan terbangun diperoleh dari interpretasi foto udara. Analisis peta isoterm didapatkan dari klasifikasi hasil pengukuran suhu di lapangan dan overlay dengan peta penutup lahan. Hasil penelitian menunjukkan bahwa terjadi pola perbedaan suhu antara lahan terbangun dengan lahan bervegetasi di kompleks Universitas Gadjah Mada. Kenaikan suhu terjadi di lahan terbangun Perempatan Terban, Fakultas Pertanian UGM, Perumahan Sekip, Fakultas Kedokteran UGM, Jalan Kesehatan sisi Timur RS Sardjito dan Fakultas Teknik UGM. Suhu tertinggi mencapai 36,30°C pada pukul 10.00 – 11.00 WIB di Perempatan Terban. Sebaliknya pada suhu rendah dijumpai di lahan bervegetasi utara BPFE UGM, vegetasi timur Fakultas Filsafat UGM, vegetasi utara Fakultas Peternakan UGM, dan Perumahan Bulaksumur. Suhu terendah sebesar 25,95°C pada pukul 06.00 – 07.00 WIB di lahan bervegetasi utara Fakultas Peternakan UG

Including the urban heat island in spatial heat health risk assessment strategies: a case study for Birmingham, UK

Background Heatwaves present a significant health risk and the hazard is likely to escalate with the increased future temperatures presently predicted by climate change models. The impact of heatwaves is often felt strongest in towns and cities where populations are concentrated and where the climate is often unintentionally modified to produce an urban heat island effect; where urban areas can be significantly warmer than surrounding rural areas. The purpose of this interdisciplinary study is to integrate remotely sensed urban heat island data alongside commercial social segmentation data via a spatial risk assessment methodology in order to highlight potential heat health risk areas and build the foundations for a climate change risk assessment. This paper uses the city of Birmingham, UK as a case study area. Results When looking at vulnerable sections of the population, the analysis identifies a concentration of "very high" risk areas within the city centre, and a number of pockets of "high risk" areas scattered throughout the conurbation. Further analysis looks at household level data which yields a complicated picture with a considerable range of vulnerabilities at a neighbourhood scale. Conclusions The results illustrate that a concentration of "very high" risk people live within the urban heat island, and this should be taken into account by urban planners and city centre environmental managers when considering climate change adaptation strategies or heatwave alert schemes. The methodology has been designed to be transparent and to make use of powerful and readily available datasets so that it can be easily replicated in other urban areas