الفهرس 
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Abstract
Cairo is the capital of Egypt and its largest city. It is considered an important political and cultural focal point in the Middle East and Africa. It suffers from high population density, rapid urban expansion, high air pollution levels and traffic congestion. This resulted in remarkable variation in temperature between urban areas and the surrounding rural communities. Leading to the formation of Urban Heat Islands (UHIs) phenomenon, which has great impacts on human being and environment.
This study aims at using remote sensing and Geographic Information System (GIS)technologies to a) detect the UHIs over Cairo city, b) define the factors contributed to enhance the UHIs effect in Cairo, c) study the influence of land use/land cover (LU/LC) on this phenomenon and d) propose mitigation measures to minimize the negative impact of UHIs.
The area of study occupies an area of 883.5Km2. It covers the city of Cairo, parts of Al-Giza and Al-Qalyobia Governorates. The Nile River is located in the western part of the study area. The study area was classified into four classes, including: urban areas (include road networks), bare land/desert, cultivated land and water bodies.
Multispectral Landsat data from 1990 to 2014 were used temporally to study the UHIs. In addition to detect LU/LC changes in Cairo and assess their correlation with land surface temperature (LST)and UHIs. LST was retrieved from Landsat thermal data by mono- window algorithm, based on three parameters: emissivity . trasmittance and mean atmospheric temperature. Standard deviation segmenting method was used to extract UHIs from LST images.
Bio-physical indices were used to quantitatively determine the effect of different land forms (vegetation water and built-up area) on LST and UHIs These indices include Normalized Difference Vegetation Index (NDVI) Normalized Difference BUILD-UP Index (NDBI) and Modified Normalized Difference Water Index (MNDWI). Moreover the effect of population density and air quality on LST and UHIs was studied.
Results showed that urban areas were increased by 16.6% during the last 24 years from 1990 to 2013 It expanded over cultivated lands desert.73 locations were observed randomly in the study area during the field survey These locations were used to validate the LU/LC and LST in different landforms and human activities such as industrial zones residential areas road networks green areas and the Nile River.
The distribution of UHIs in Cairo depends mainly on LST and the type of LU/LC The highest LST values and UHIs were observed in bare land/desert and built-up areas recording 51.8c, 48.7c, respectively While the lowest LST values were observed in cultivated lands and water bodies recording 38c and 29.2c respectively (in summer 2013) UHIs were located in built-up areas (eg. Misr Al-Qadima) industrial areas (eg. Shobra El-Khema )and transportation centers (eg. Cairo Airport )This returns to the excessive heat release from human activities artificial surfaces roof materials (eg. Aluminum )as well as thermal heat emission from industrial activities in addition to the high levels of air pollutants from industry and transportation.