Study On Characteristics And Evaluation Methods Of Heat Island In Mountainous City

The energy consumption amount is increasing with the rapidurbanization of mountainous cities in the west of China. City scale, styleand features were given priorities in urban planning, which resulted innumerous large buildings and high density building landscapes. While theurban environment, especially outdoor thermal environment wasconsidered less, which aggravated the outdoor thermal environment inmountainous cities and brought a series of undesirable influences to urbanenvironment and citizen’s lives, and urban heat island (UHI) was the mostobvious one. Currently, most of the field measurements of urban heat islandwere using urban-rural dichotomy to calculate heat island intensities.Urban-rural dichotomy was so easy to understand and convenient forcalculation that it was accepted and applied widely. However, Urban-ruraldichotomy had limitations that it ignored the surface properties thatinfluence the climate of observation sites in various local scales.The study focused on the characteristic of urban heat island effect ofmountainous city–Chongqing, attempting to redefine urban heat islandintensity with inter-zone temperature differences based on manyexperimental observations and propose a new UHI evaluation method.With these aims, the thesis has done the following work:①High temperature weather background was analyzed and thepoint-mode feature of heat island in Chongqing were represented with datafrom Shapingba, Beibei, Yubei and Banan, which are four meteorologicalstations in the main city of Chongqing.②The belt-mode feature of heat island in Chongqing wererepresented using mobile survey data, which were obtained from35timesof mobile survey carried out in the main city of Chongqing. A mathematicmodel for calculating urban heat island intensity using moving observationdata was proposed. Furthermore, a new data processing method for mobilesurvey was proposed by designing the roundtrip mobile survey route.③Four scenes of Landsat TM images which were obtained onSeptember15th,1988; September11th,1998; September1st,2006and August24th,2009separately were utilized, the corresponding surfacetemperature of Chongqing were retrieved with mono-window algorithmcarried out by Qin Zhihao. Besides, an earth-satellite synchronizingobservation was carried out in order to verify the accuracy of the retrievedresults. Heat island in Chongqing during the21years from1988to2009was analyzed, representing the planum-mode feature of heat island inChongqing.④Existing problems of urban-rural dichotomy were analyzed from51heat island study cases in6cities, and criterion for classifying UHImeasurement sites and landscape were proposed, with which the landscapeof Chongqing was classified into4series and18thermal climate zones. Anillustrative set of datasheets was designed to standardize the record of sitemetadata for heat island investigators. Then, temperature differencesamong thermal climate zones were calculated with the support of mobilesurvey data and UHI was redefined with the inter-zone differences, whichis considered to be a new evaluation method of UHI. Value of heat islandintensity was classified into three classes considering two factors, thesurface morphology and physical fabric, and their relations werequalitatively analyzed. Furthermore, the evaluation methods and features oftraditional urban-rural temperature differences and inter-zone temperaturedifferences were summarized and analyzed.⑤Urban heat island information management system based ongeographic information system was developed with Visual C#programming language and Arc Objects components to integrate the UHIobservation results and corresponding evaluation method. Basic comprisingand functions of the system were then introduced.The study has portrayed the point-mode, belt-mode and planum-modefeatures of heat island in mountainous city Chongqing. A new UHIevaluation method was proposed, and UHI was managed with aninformation system. The study results can be used for guiding the mobilesurvey practices and standardizing the metadata record of UHImeasurement site, as well as to promote the city’s information managementlevel in the environmental fields. The study can also be a reference forurban planning and sustainable development of mountainous cities.