Uploaded on 2016-04-21 by JennyPeeva

**Which are the main UHI effects that you can identify in your area?** The main UHI effects in my area are the temperature inversions. The city of Sofia (elevation 550 m) is located at the foot of Vitosha mountain (2224 m) and there is a ring of lesser mountain formations around it. It is common that the difference between the warmest and the coldest surface temperature could exceed 15°C in summer days (Pongrácz et al, 2009). This temperature gradient is especially well manifested in summer due to the close proximity with the mountain and Vitosha's high elevation, compared to the urban area. Sofia's neighboring mountains combined with the urban heat island effect lead to the development of three main temperature differences, namely: ground, elevated and capping. There are also definite vertical profiles of the wind velocity (Kolev et al. 2013). In the picture below are shown Sofia's garden parks and surrounding national parks. We can see multiple rivers and green spaces, which improve the air quality of the city. The majority of buildings are not very tall and older urban design practices allowed for ample space between the building bodies, securing free flow of air. Even so, the recent growth in commercial and residential sectors present the need for more UHI mitigating measures. ![Grean territories around Sofia][2] ![Sofia and surroundings from one of the mountains][3] **Which are the measures you would propose?** I would suggest measures, related to building envelope renovation (for old buildings), including insulation, to improve their energy efficiency and a mandatory building energy level of B or higher for new constructions. In addition, I would encourage the development and many new green spaces, as well as promoting the preservation of the existing ones. **Is UHI effect concerning policy making in your area?** An example of such measure would be planting trees along heavy traffic roads to reduce both levels of noise, heating of the asphalt and the air quality. In articles on www.mediapool.bg and www.dnes.bg, we read that Sofia municipality will be planting 12 600 trees and close to 200 000 flowers along the streets of Sofia in 2016 and 12 000 more trees will be planted in 260 dka forest areas nearby. 5 mil. EUR more will be spent in 2016 to improve the spaces between residential blocks. Streets will be cleaned 5 times as often to reduce the buildup of dust and fine particles in the air. In 2016 many new metro stations will be opened in Sofia, reducing the car traffic and further improving air quality. All these tangible actions are part of the reason why Sofia is in Forbes top 10 places for starting a business in 2015. In addition Sofia is rated first in growth of GDP, shown for the last 10 years according to Blumberg Sources used: [1]: https://edxuploads.s3.amazonaws.com/14612266004429027.jpg [2]: https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRMH8yi7hqjsVM4sK42JYEOVohoFWZ5HAH1SILwX_-0GBhUi0Ho3A [3]: https://edxuploads.s3.amazonaws.com/14612294102038956.jpg 1]: https://edxuploads.s3.amazonaws.com/14612266004429027.jpg 2]: https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRMH8yi7hqjsVM4sK42JYEOVohoFWZ5HAH1SILwX_-0GBhUi0Ho3A 3]: https://edxuploads.s3.amazonaws.com/14612294102038956.jpg [4] http://www.mediapool.bg/stolichnata-obshtina-shte-zasadi-12-600-darveta-i-180-000-laleta-news247750.html [5] http://www.dnes.bg/sofia/2015/12/17/sofiia-prez-2016-ta-chisti-ulici-zeleni-ploshti.286881 [6]: Urban heat island effect of large central European cities using satelite measurements of surface temperature; Rita Pongrácz , Judit Bartholy, Zsuzsanna Dezső, Enikő Lelovics Eötvös Loránd University, Budapest, Hungary, 2009 [6] Lidar observation of the nocturnal boundary layer formation over Sofia, Bulgaria, Atmospheric Environment 34(19):3223-3235 • July 2013, I. Kolev, P. Savov et al.