*3 rd year student, B.A Special Environmental Management Degree Program, Department of Social Sciences and Humanity, Rajarata university of Sri Lanka “Steps to green world” 1 st academic seminar series In Rajarata Univerity of Sri Lanka, Faculty of Social sciences and Humanity Assessment of Intensity of Urban Heat Island Effect in Sri Lanka Cities M M T D KASTHURI* EXTENDED ABSTRACT Key Words Urban Heat Island; Land-Use Land-Cover, Surface Air Temperatures, Remote Sensing 1. INTRODUCTION With the recent increasing demands of the population, urban spaces expanded dramatically, much faster and with much more significant changes, than in the previous decades. The large areas that modern cities occupy, their structure, materials and the general lack of vegetation have altered the climatic characteristics of urban spaces. According to the Population Reference Bureau 50% of the world population (3.4Billion) is settled in urban areas. Also it is predicted that inhabitation in cities will reach 60% (5.0Billion) by 2030, which means around two billion more people will reside inside cities by that year. In addition, the number of cities with population of over one million is expected to increase by approximately100 from 2005 to 2015 (Halwatura, R.U; Wijerathna, S.N). Massive construction of buildings and physical infrastructure is under way to respond to this increased population demand. This excessive growth of urbanization has caused undesired side effects around the world. Urban Heat Island (UHI) as a consequence of urbanization was first documented by Howard in 19th century. With the rapid development in Sri Lankan cities soft land cover areas have been reduced and hard land cover areas have been increased over time affecting its bioclimatic conditions. As a example, the average air temperature of Colombo city for last 100 years (1901-2001) was remained around 27 0 C with more positive deviations in the recent past and very significant trend of increase in the future (Dayawansa,N.D.K; Ukwattage, N.L;,2012). This land use changes can cause temperature building up in the urban centers compared to none urbanized vegetative surroundings which is identified as formation of urban heat island. This paper discussed about the objectives of the literature survey and different perspectives of urban heat island. Finally it described basics of UHI effect in global and Sri Lankan perspectives and importance researching on urban heat island effect on emerging cities.  General objective This study focuses on to obtain a profound knowledge about the urban heat island effect.  Specific objectives To ascertain of urban heat island effect concept Identification of factors contribute to urban heat island formation Identification of methods to measure urban heat island effect Identification of impacts of urban heat island effect Identification of mitigatory measures to reduce the heat island effect Study about urban heat island effect in Sri Lankan Context