关键词: 冬小麦；拔节期；积温；陆面温度；遥感监测

Abstract:

Remote sensing data has the characteristics of spatial continuous imaging and repeated sampling. It can be used for monitoring regional wheat jointing stage, and then provide basic data for studying and monitoring of winter wheat late freezing injury. Taking winter wheat planting area in Henan Province as studying area, this paper firstly established the equation between the accumulated temperature and the cumulative value of land surface temperature (LST). And the LST data was provided by remote sensing. On this basis, the accumulated temperature demand quantity of winter wheat from turning green to jointing was transformed into the accumulated LST demand quantity. Then starting from turning green date, the date when the accumulated LST value reached its demand quantity from turning green to jointing was calculated by using the Terra/MODIS LST data product MOD11A2. And the date is the jointing stage start time. The results showed that the wheat jointing start date concentrated in late March to early April. The annual temperature differences could cause significant fluctuations in jointing start time. From the view of spatial distribution, except for Xinyang area, the jointing start time of winter wheat from south to north gradually postpone in Henan Province. The error between the monitoring results and the observation values could be controlled within 5 d in most cases, which showed that remote sensing data, LST, together with the accumulated temperature model could be used to monitor the jointing stage.

Key words: winter wheat, jointing stage, accumulated temperature, land surface temperature, remote sensing monitoring