Analysis On Heat Island Effect In Coastal Urbanization Area Using Remote Sensing Data

The urban heat island effect is one of the most significant MeteorologicalAnomalies in the process of urbanization. The urban heat island effect is becomingincreasingly serious with the accelerated urbanization Process, and using remotesensing technology for urban heat island research has now received much moreattention as a scientific trend and hotspot. The coastal area has more environmentalproblems because of its highest urbanization rate with the expanding urban areaduring the past30years. The urban heat island research, however, is underestimatedowing to more favorable climate of coastal city. So this research aims to set up anexample can provide a reference for the coastal cities, and could become an importantguidance on the city planning and environment management.Based on Landsat TM thermal infrared band, this research retrieved the landsurface temperature (LST) of the Qingdao area with three different methods:Radioactive Transfer Equation, Mono-window Algorithm and Single-channel Method.After comparing and analyzing the retrieved data, the results showed that the generaltrend of the LST retrieved from the three methods is much more consistent, and theMono-window Algorithm is the most suitable for this research. For the convenienceof land surface temperatures retrieving, a basic technological process of land surfacetemperatures Retrieving system was developed by using C#language mixed withENVI/IDL and ArcGIS Engine.Compared retrieval LST image in1990,2000and2010, this research showed thathigh brightness temperature areas are mainly distributed in urban land-useconcentrated areas and increased as year pass by. In addition, this paper compared theseasonal change of urban thermal environment and concluded that the heat islandeffect on summer is the most noticeable in the Qingdao area. This paper expounded the driving mechanism of urban heat island effect in theQingdao area from three aspects: Underlying Surface, Land Use and Land CoverChange (LUCC), Social Economic. And Spatial Principal Component Analysismethod was employed to reveal the main ingredients. Bivariate correlation wasperformed among the LST and the factors of Underlying Surface including elevation,slope, vegetation coverage, impervious surface and the distance from the coast, andthe results had showed a significant linear relationship with the LST in addition to thedistance from the coast. It was found there was a very close relationship betweenLUCC and the urban heat island effect: the LST of unexploited land and urban landwas the highest, the thermal effect contribution index of cultivated land and urbanland was the most significant; the transfer of gravity center of urban area wasconsistent with heat island from2000to2010; the comprehensive index of land usedegree had a significantly positive correlation with the LST in2010and there wasalso a positive correlation between social economic and the LST. Furthermore, therewere four primary factors influencing the formation of the urban heat island effect inQingdao area, which could be respectively generalized as vegetation coverage,landscape pattern, slope, land surface mulching in1990, and vegetation coverage,landscape pattern, social economic, urban construction in2000, and LUCC,vegetation coverage, landscape pattern in2010. Linear model including the fourindependent variables could reveal the driving mechanism of urban heat island effect.