مصداقية استخدام المرئيات الفضائية في بناء نماذج كارتوجرافية للجزر الحرارية بالمناطق الحضرية : دراسة حالة : القاهرة الكبرى

الملخص EN

Since 1970s remotely sensed data were widely employed to derive land surface temperature.

It should be noted that despite satellite images used in detecting land surface instead of air temperature, they provide an accurate indicator to air temperature in low layers of atmosphere adjacent to land surface.

Therefore, remote sensing images provide very useful data on various geographical phenomena particularly when ana-.lyzing such data with geographical information systems Heat islands refer to those areas that experience higher temperature than background surface temperature.

This phenomenon is generally associated with urban areas due the concentration of human activities and associated high levels of energy consumption, which contributes to higher air and surface temperature within urban areas.

Generally, studying urban heat island assists in identifying spatial differences in temperature within urban area.

This, consequently, provides better understanding of urban environment and contributes to improve quality of urban life.

The paper in hand aims at assessing the credibility of using LAND-SAT ETM+ images in studying and analyzing urban heat islands in Greater Cairo as a study area.

The study used two satellite images of the area dated 23/08/2000 and 11/11/2000, respectively.

Firstly, the land surface temperature was derived from the two satellite images, and the heat islands were identified.

Various factors affecting spatial distribution of urban heat islands were also analyzed.

Thereafter, based on traditional records of air temperature acquired from five meteorological stations distributed in various parts of the study area, air temperature was calculated from land surface temperature on the basis of the relationship between land surface and air temperature.

The pattern of temperature in the study area during August and November reveals a number of heat islands in the marginal desert parts in addition to industrial areas in southern and northern parts of the study area.

This result was found to be consistent with the results of the previous studies, which were based on traditional meteorological records.

Furthermore, it was noted that the locations of urban heat islands in both August and November were found to be identical.

Moreover, the study indicated that air temperature can be calculated based on the land surface temperature derived from satellite images.

This, in turn, assists in developing more reliable models for urban heat islands with a synoptic coverage and high spatial resolution highlighting the spatial differences in temperature accurately.