南京市热岛效应变化时空特征及其与土地利用变化的关系

Spatial-temporal characteristics of urban heat island effect change of Nanjing city and its relation with land use change

利用遥感数据和气象统计数据分析自1985年以来南京市热岛效应变化的时空特征及其与土地利用变化的关系。结果表明:自1985年以来,南京市热岛效应强度和范围在增长。南京市的年均温逐年上升,与郊区六合县的温差呈上升趋势;南京市建成区内4级热岛效应面积增加了107.88km2。热岛效应增长在空间上存在差异,大厂>雨花台>市辖区>栖霞>浦口>江宁。南京市土地利用变化的结果使得热岛效应空间分布更广泛,城镇居民点及工矿用地利用强度变化最大的地方即城市热岛效应增加最多的地方,两者在空间上具有很好的吻合;而和城镇居民点及工矿用地的扩展规模没有很好的空间相关性。

How to analyze the change of urban heat island effect（UHIE） and its quantificational relations with land use is one of the difficult problems in the study of the formation mechanisms of its driving forces.This paper analyzes spatial-temporal characteristics of UHIE intensity and scope change of Nanjing city and its relations with land use change using remote sensing and meteorological data.The results indicate that both scope and intensity of UHIE have been increasing since 1985.Viewing from the change of intensity,the changing tendency of annual mean temperature has been going up but the changing tendency of Nanjing city is different from its suburban county of Liuhe,being 0.16℃ during 1986~1990,0.18℃ during 1991~1995 and 0.262℃ during 1996~2000.From the change of scope,the scope of four-level UHIE in Nanjing built-up area has added 107.88 km2 since 1985.There were two core districts of UHIE in 1985,the biggest one was distributed in Xinjiekou,Fuzimiao and places south of it,the other was in the vicinity of railway station and bus station in Nanjing city.There were three intense UHIE centers in 2000,two of which were in the same positions of the major two in 1985,but their scope increased compared with the former ones.The other one was in the industrial district of Dachang and Pukou.The index of UHIE is used to probe into the spatial difference of UHIE evolution during 1985~2000,the six districts are in the order of Dachang〉Yuhua〉Shixia〉Qixia〉Pukou〉Jiangning.The major characteristic of land use in Nanjing city is the conversion of natural landscape such as cultivated land,greenbelt and water to man-made landscape.The change of vegetation cover,soil moisture and artificial heat because of land use change is the main reasons of the effect of land use change on urban heat island.According to NDVI,TVDI,artificial heat and LST of every kind of land use,the temperature effect index is provided to evaluate the effect of land use change on urban heat island.The results indicate that land use change in Nanjing city leads to more extensive and intensive urban heat island.The region where urban construction land expands most quickly is also where the urban heat island increases most quickly and the expansion of urban construction land doesn＇t accord with the increase of urban heat island in space.