MODIS数据反演三江平原晴空上午陆表温度比较研究

三江平原大面积开垦后区域水热平衡发生变化,晴空上午陆表增温状况在开垦后和未开垦区域之间周年变化表现不同.选择2006~2009年55个时次67个Terra卫星上午降轨MODIS L1B数据集,在黑龙江南岸乌苏里江西岸开垦后农田、黑龙江北岸乌苏里江东岸俄罗斯境内未开垦平坦荒原各选择200个地面数据点,比较分析开垦和未开垦区晴空上午陆表温度(Land surface temperature,LST).结果表明,与未开垦荒原比较,开垦后区域LST年变化表现为两谷一峰:春季解冻后未开垦区有大量枯萎植物覆盖,开垦后区域裸土为主,表现为温度谷;5月下旬至7月中下旬,未开垦区植物大量生长,开垦区农田前期多为裸土或植株矮小,表现为一个很强的温度峰;7月末至8月末农田作物茂密生长,表现为另一个温度谷;9月以后至次年4月份大部分时间为冻土或被冰雪覆盖,开垦区和未开垦区LST差异不明显

Study on morning land surface temperature retrieval of Sanjiang Plain using clear sky MODIS data

Water and heat balance of Sanjiang Plain has been changed after large area of reclamation.The increasing land surface temperature(LST) in morning of clear sky conditions performs an annual variation between cultivated and uncultivated land.200 pairs of the sample data points distributed on the south bank of the Heilong River and the west bank of the Wusuli River in China and on the north bank of the Heilong River and the east bank of the Wusuli River in Russian were selected from reclaimed and unreclaimed lands respectively.67 Terra Satellite descending orbit MODIS L1B granules from 55 days were used in this study.The results indicate that compared with the uncultivated wild land,LST annual variation of the cultivated area exhibits two valleys and one peak that are as follows: The first temperature valley appears after thawing in spring,when uncultivated area were covered with wilted plants while cultivated area are mostly bare land;From late May to mid/late July is a strong temperature peak,during that period plants grow well in uncultivated area and cultivated farmlands are still bare land or covered with thin plants;Another temperature valley is from late July to the late August,farmland crops flourishing at that time;From September to April of the next year,both uncultivated and cultivated areas are frozen soil or covered by ice and snow,their LST difference area unobvious.