Uploaded on 2015-12-15 by sharan_k

**Check the temperature differences in US cities** analysis of summer temperatures in 60 of the largest U.S. cities found that: • 57 cities had measurable urban heat island effects over the past 10 years. Single-day urban temperatures in some metro areas were as much as 27°F higher than the surrounding rural areas, and on average across all 60 cities, the maximum single-day temperature difference was 17.5°F. • Cities have many more searing hot days each year. Since 2004, 12 cities averaged at least 20 more days a year above 90°F than nearby rural areas. The 60 cities analyzed averaged at least 8 more days over 90°F each summer compared to adjacent rural areas. • More heat can increase ozone air pollution. All 51 cities with adequate data showed a statistically significant correlation between higher daily summer temperatures and bad air quality (as measured by ground-level ozone concentrations). Temperatures are being forced higher by increasing urbanization and manmade global warming, which could undermine the hard-won improvements in air quality and public health made over the past few decades. • In two thirds of the cities analyzed (41 of 60), urbanization and climate change appear to be combining to increase summer heat faster than climate change alone is raising regional temperatures. In three quarters (45 of 60) of cities examined, urbanized areas are warming faster than adjacent rural locations. • The top 10 cities with the most intense summer urban heat islands (average daily urban-rural temperature differences) over the past 10 years are: • Las Vegas (7.3°F) • Albuquerque (5.9°F • Denver (4.9°F) • Portland (4.8°F) • Louisville (4.8°F) • Washington, D.C. (4.7°F) • Kansas City (4.6°F) • Columbus (4.4°F) • Minneapolis (4.3°F) • Seattle (4.1°F) • On average across all 60 cities, urban summer temperatures were 2.4°F hotter than rural temperatures. Urban heat islands are even more intense at night. Over the past 10 years, average summer overnight temperatures were more than 4°F hotter in cities than surrounding rural areas. **Which are the main UHI effects that you can identify in your area?** ![enter image description here][1] the existence of heat island effect in the city of Chennai with increasing air temperatures in a radial fashion from the suburbs towards the city centre where the mean max UHI intensity reaches 5.5°C in stationary survey and 2.53°C in the mobile survey. The ETM+ data shows the increase in urban built up areas and the reduction of vegetated areas. The thermal bands of Landsat TM and ETM+ are used in identifying the specific locations of micro urban heat islands within the city. The various land cover types such as dense vegetated areas, barren land and industrial areas, dense built up spaces, water bodies etc contributes to the variation in temperatures leading to the formation of urban micro heat islands. With the increasing energy demand it is possible to reduce the energy needs by mitigating the effects of these micro urban heat islands **Which are the measures you would propose?** 1. Reduction of Anthropogenic Heat Emission In order to reduce anthropogenic heat emission from such as air conditioning, electric equipments and automobiles, following measures shall be carried out; ・ Facilitation to improve efficiency of energy consuming equipments by subsidizing new technology development and installation of its outcome. ・ Facilitation to diffuse high energy efficient houses and buildings by policy-based finance, model projects developing environment friendly houses and urban areas and utilization of “Energy Service Company (ESCO)” ・ Facilitation of the technology development and the diffusion of low emission vehicles ・ Traffic control measures, facilitation of rationalization of the distribution and encouraging use of public transportation ・ Encouragement of the use of new energy 2. Improvement of Urban Surface In order to mitigate decrease of evapo-transpiration and the high temperature rise of the ground, - 5 - which were caused by reduction of green space and water and expansion of impervious surface such as buildings and asphalt, the following measures for the improvement of urban surface shall be carried out; ・ Facilitation of tree-planting in private houses, buildings and their sites ・ Promotion of tree-planting in public facilities such as government buildings ・ Construction of urban parks and promotion of tree-planting in public spaces such as ports, airports and sewage plants 3. Improvement of urban structure In order to ensure wind flow through green spaces and water, following measures for the improvement of urban structure shall be carried out; ・ Development of network with green and water in the region across the prefectures by construction of large green spaces and making up the linkage between parks, rivers and roads ・ Feasibility study on the urban heat emission treatment system which carry heat from the very densely build-up area to rivers and sea through under-ground pipes with circulating water ・ Facilitation to utilize the city planning system to develop “less environmental burden cities”. 4. Improvement of Life-style UHI phenomenon is closely linked to socio-economic activities in the city. Therefore, following measures shall be promoted to improve life-style; ・ Promotion of actions taken by business and families to utilize new energy and to save energy such as utilizing sunshine and air heat energy and to collect and utilize rainwater ・ Promotion of light clothes in summer ・ Facilitation of summer vacation to reduce anthropogenic heat emission in the cities ・ Facilitation of efficient use of cars by eco-driving and so on Vegetation to a large extent can improve the thermal environment. At city level, large green patches can reduce night time air temperatures. At micro level, trees and plants surrounding the built up spaces can reduce the absorption of solar radiation. The UHI effect is a common feature found in most cities. Therefore the basic strategies applicable to all cities in mitigating the negative impacts of UHI are shading the hard surfaces that are directly exposed to sun, greening the city and reducing the anthropogenic heat and use of light color materials to save cooling energy. **Is UHI effect concerning policy making in your area?** .NO The concept is not very popular . Only a very few scholars are working on the topic mostly being architect . enter image description here![enter image description here][2] [1]: https://edxuploads.s3.amazonaws.com/14502053171047623.jpg [2]: https://edxuploads.s3.amazonaws.com/14501205108199606.jpg