冬小麦冠气温差及其相关影响因素关系研究

Difference of Canopy-air Temperature and Its Affecting Factors

在冬小麦主要生育期(2002年的4月初到5月底),对3个不同水分处理测定了冠层温度、气温以及土壤含水率和叶面积指数,并进一步计算了冠气温差并分析了冠气温差与土壤含水率和叶面积指数间的关系。结果表明:不同的灌溉措施对冠气温差的影响是有差异的;中午14:00左右在H2高度处(冠层之上)的冠气温差能反映作物的水分特征,可以用此时刻的实验结果来检验遥感数据反演冠气温差的精度;在60～80cm土层的土壤体积含水率能较好地反映中午14:00冠层之上冬小麦冠气温差的变化情况,不同水分处理二者的相关系数(R2)分别为0.60361(节水灌溉),0.95668(充分灌溉),0.84597(不灌溉);不同水分处理下的冬小麦主要生育期的叶面积指数与冠气温差也有一定的相关性,冠层之上二者的相关系数分别为:0.76082(节水灌溉),0.40548(充分灌溉),0.99499(不灌溉),这为区域上遥感反演作物冠气温差来监测土壤含水率及作物估产提供了依据。

In the growth stage of winter wheat (from April to May in 2002), the canopy temperature, air temperature, volumetric soil water content and leave area index were measured for three different water treatments, and canopy-air temperature difference and relationship among canopy-air temperature difference and volumetric soil water content, leave area index were analyzed in this paper. The results indicated that influence of different irrigation treatments on canopy-air temperature difference is different; the canopy-air temperature difference on the height of H2 (above canopy) at 14:00 can reflect crop water stress, also can be used to examine the accuracy of canopy-air temperature by using Remote Sensing methods. Change of volumetric soil water content at the depth 60～80 cm can preferably reflect changes of canopy-air temperature difference at 14:00,the R^2 respectively are 0.60361(saved-water irrigation), 0.95668 (full irrigation), (0.84597)(no irrigation). There is also certain relation between leave area index and canopy-air temperature difference different water treatments, the R^2 respectivelyare 0.76082 (saved-water irrigation), 0.40548 (full irrigation), 0.99499(no irrigation).The results of this study can probably be used to monitor crop water stress and estimate crop yield by combining Remote Sensing and crop simulation model.