Spatial Analysis of Land Surface Temperature distribution: Case of Greater Beirut Area
The currently accelerated urbanization modifies the geographic energy balance by making city centers warmer than their outlying zones. This phenomenon is exemplified by urban heat islands. Globally, the warming of urban zones leads to an increase in land surface temperature (LST). This is why the study of LST is nowadays one of the key scientific interests. Nonetheless, the sophisticated relationship between the LST and the determining factors has not yet been fully investigated especially in terms of indirect in addition to direct effects. This paper proposes a new structural methodology that contributes to the emerging literature by quantifying the direct and indirect effects, among latent variables, of factors that could significantly influence the distribution of land surface temperature. The driving factors are divided into two classes: natural geo-topographic aspects and human interventions; and the methodology is developed in the contextual form of the structural equation models, based on satellite remote sensing and statistical data for Lebanon which is the field of application of this study. The results show that: (1) the LST increases simultaneously with extended urban and human activities; (2) the human activities and the land surface temperature decrease where the topographic and geographic aspects, mainly as the elevations and slopes, increase. However, indirect linear regressions reveal that the geo-topographic aspects present some contradictive natural properties that counteract and resist the contribution of human activities in elevating the land surface temperature. Putting this methodology into practice is essential as guiding tool for future urban planners and decision makers in the phase of developing and implementing solutions and enacting relevant policies. The results could also be employed (a) for identifying potential sources of renewable energies and (b) when developing effective solutions to reduce these temperatures. In accordance with benefits, the authors recommend exploiting the urban heat islands, presented mainly in the airport and the seaport areas, as a good source of thermal energy that could be used and converted to other types of stored energies. However, further studies are exacted to evaluate the employment of the LST as an efficient thermal energy source as well as studying the effects of climate changes and air circulations on surface temperatures. Keywords: Land Surface Temperature, Structural equation model, Urban heat island, Lebanon.