基于遥感资料研究合肥城市化对气温的影响

Impact of Hefei Urbanization on Temperature Observation Based on Remote Sensing Data

为了探讨城市化进程对城市区域气温的影响程度,利用高分辨陆地卫星影像结合GIS技术揭示了近30年合肥城市化进程及其对气象观测场周边土地利用/覆盖变化(LUCC)的影响过程;进一步分析了1970—2008年合肥气象站与其周边的肥西和肥东气象站观测的年平均、最高和最低3项气温的动态变化特征,并最终建立了合肥气象观测场周边LUCC与气温的关系模型。结果表明,近30年来,合肥建成面积在不断扩大,从而导致了气象观测"进城"而先后进行搬迁的现象,继而产生了气温序列的非均一性。1979—2003年期间,合肥观测场由于受到城市扩张影响显著,合肥站3项气温的增温速率均明显大于肥西和肥东站3项气温增温速率。合肥观测场周边半径为4 km缓冲区LUCC对平均气温和最低气温的变化有显著影响。建成面积的增加对平均气温、最低气温有正贡献;而耕地、植被、水体的增加却对平均气温、最低气温存在负贡献。

Based on the data from Hefei and its surrounding sites and MSS,TM and ETM data of Hefei City,and GIS technology,the land use/cover change（LUCC） situations of buffer areas,which are apart 1,2.5,4 km from Hefei observation field and 20 km from Hefei urban areas,Were extracted.Variations of annual average,maximum and minimum temperatures（T_（ave）,T_（max） and T_（min）） were analyzed in Hefei and its surrounding sites,respectively.Furthermore,the regression model between LUCC of Hefei observation field and temperature was established,and a sensitivity analysis was also made.The results have shown that in recent 40 years,the urban area of Hefei has been expanding,thus leading to the site entering into city.Due to this,Hefei Site moved to the suburbs in 1979 and 2004,respectively.After that the temperature difference between Hefei and its surrounding sites became smaller.Because of Hefei Site entering into city,increasing rates of three temperatures in Hefei Site were significantly higher than those in its surrounding sites,and the differences of T_（ave）,T_（max） and T_（min） between Hefei and its surrounding sites became bigger.The regression model between LUCC and the temperature in different buffers area showed that impacts of LUCC on T_（ave）,T_（max） and T_（min） were not sensitive in Hefei observation field＇s 1 and 2.5 km buffer areas.Similarly,impacts of LUCC on T_（max） were not sensitive in Hefei observation field＇s 4 km buffer area, while impacts of LUCC on T_（ave） and T_（min） were significant.Specifically,the increased building areas had a positive contribution to T_（ave） and T_（min） in Hefei observation field＇s 4 km buffer area;Oppositely,the increased farmland,vegetation,water body areas had a negative effect on T_（ave） and T_（min）.