珠三角城市群城市热岛与地表覆盖时空变化分析

Spatio-temporal Variation Analysis of Urban Heat Island and Land Cover in Pearl River Delta

以珠三角城市群为研究区,基于地表温度和土地利用两种MODIS数据,研究了2005—2019年珠三角城市群城市热岛的年际和季节变化特征及其地表覆盖的时空变化情况,分析了珠三角城市群不同土地利用类型在2005—2019年的地表温度年际和季节分布。研究结果表明,2005—2019年珠三角城市群的城市热岛效应明显,呈倒“U”型的逐年增长趋势,城市热岛强度各年均在2.48℃以上;城市热岛表现出明显的季节变化特征,即夏季最强,其次是秋季和春季,冬季最弱;珠三角城市群的建成区面积逐年扩大,且2005—2012年的增长快于2012—2019年,相应的,其城市热岛强度2005—2012年的增长高于2012—2019年;珠三角城市群各土地利用类型的地表温度分布趋势相同,均表现为建成区的地表温度最高,林地和水体的地表温度较低,且各土地利用类型在夏季的地表温度最高。研究结果可为城市热岛的缓解和城市热舒适度的提升提供一定的参考。

Taking the Pearl River Delta(PRD)as study area,we used two MODIS data,which were MODIS land surface temperature(LST)and land cover data,to study annual and seasonal variations of urban heat island(UHI)and land cover in PRD from 2005 to 2019,and analyzed annual and seasonal variations of LST for different land cover types in PRD from 2005 to 2019.Results showed that UHI effect was obvious in PRD from 2005 to 2019.The UHI showed an inverted U-shaped increasing trend,and intensity of UHI(UHII)were above 2.48℃in all years.The UHI of PRD showed obvious seasonal variations.The strongest UHII occurred in summer,followed by autumn and spring,and the weakest in winter.The built-up area of PRD increased from 2005 to 2019,and the increase from 2005 to 2012 was more than that from 2012 to 2019.Accordingly,the increase in UHII of the PRD from 2005 to 2012 was higher than that from 2012 to 2019.From 2005 to 2019,the LST of all land cover types in PRD showed the same distribution trend,with the highest LST in built-up area,the lowest in forest and waterbody,and the highest LST in summer for all land cover types.The study can provide some references for the mitigation of UHI and the improvement of urban thermal comfort.