基于MODIS的武汉城市圈地表温度场特征

地表温度是许多研究领域，如环境、生态、水文、气候、农业、浅层地温能、热岛效应等不可或缺的重要参数，这些参数现在可以通过卫星热红外遥感技术方便地获得。对一年的MODIS 8 d合成地表温度产品进行了处理，得到了武汉城市圈的地表年平均温度、年温度变幅、日温度变幅、年最低温出现时间、日最高温出现时刻等参数的分布图，并对这些参数的分布特征与土地利用现状进行了对比分析，初步揭示了该区的地表温度时空变化规律。结果表明，这些参数受到城市热岛效应、下垫面和地形因素的强烈影响，年平均温度以城市地区最高，平原地区其次，北部和南部山区的年平均温度最低；地表水体与其附近陆地相比，年平均温度的差异并不显著，但是其年温度变幅、日温度变幅都明显比陆地小，同时，年最低温出现时间、日最高温出现时刻都明显滞后，这些是水与岩土相比具有较高比热容的必然结果。〖

CHARACTERISTICS OF LAND SURFACE TEMPERATURE FIELDSIN WUHAN METROPOLITAN REGION USING MODIS DATA

Land surface temperature(LST)is the indispensable important parameter for many research areas,such as environment,ecology,hydrology,climate,agriculture,shallow geothermal energy,heat island effect,etc.Now，these parameters can be obtained through satellite infrared remote sensing technology.In this paper,we processed one year’s MODIS dataset of“Land Surface Temperature & Emissivity 8 Day L3 Global 1 km”,and obtained the spatial distribution maps for the annual average，annual amplitudes and daily amplitudes of LST and appearing times of the annual minimum LST and diurnal maximum LST in Wuhan Metropolitan Region(WMR).We also compared these maps and the current land use map,and revealed the preliminary regulation of temporal and spatial variation of LST in WMR.Results showed these LST parameters were affected strongly by heat island effect,underlying surface and topography factors.The annual average LST was highest in urban areas，lowest in the Northern and Southern mountain areas and average in the plain areas.There were no marked differences between the annual average LST of inland water(such as the Yangtze River and Han River,Lakes and reservoirs)and that of their neighbor lands,but the annual amplitudes and dual amplitudes of LST of inland waters were significantly smaller than their neighbor lands,and their appearing times of the lowest annual LST and highest dual LST were also lag much behind that of neighbor lands.It is the inevitable outcome that the specific heat capacity of water is greater than that of soil and rock.〖