蔬菜作物水分胁迫遥感光谱指数构建实验研究

蔬菜作物干旱程度是影响其长势及产量的关键因素,实时掌握其各生长阶段的干旱程度在农业估产、旱情监测等方面具有重要的意义。利用遥感监测技术可以快速、方便地获取作物的生长信息,对其各生长阶段的干旱程度进行实时监控和防治。通过同种小白菜在不同供水量条件下的室内实验,用ASD光谱仪实测其整个生长周期的冠层光谱。通过分析小白菜在不同供水量条件下的光谱特征,利用可分性度量方法构建归一化水分指数,实现了对小白菜整个生长阶段水分含量信息的识别;之后在已有卫星遥感器波段设置的基础上,通过可分性度量与因子分析相结合的数学方法构建两个光谱指数:生长指数(GI)和干旱指数(DI),实现了对小白菜的生长阶段及干旱程度的准确识别。室内实验直接观测得到的结果也为星载数据的使用提供了依据。

Experimental study on remote sensing spectral index of water stress in vegetable crops

The drought degree of vegetable crops is the key factor affecting its growth and yield.It is of great significance to grasp the drought degree of each growth stage in real time in agriculture estimation, drought monitoring and so on.Using remote sensing monitoring technology, the growth information of crops can be obtained quickly and conveniently, and the drought degree of each growing stage can be monitored and prevented in real time.In this paper , through the indoor experiment of the same pakchoi under different water supply conditions, the canopy spectra of the whole growth period were measured by ASD spectrometer.By analyzing the spectral characteristics of pakchoi under different water supply conditions,the normalized water index was constructed by the method of separability measurement,and the information of water content in the whole growth stage of pakchoi was recognized.Then, on the basis of the band setting of satellite remote sensor, two spectral indices are constructed by combining the separability measurement with factor analysis:growth index (GI) and drought index (DI).It has realized the accurate identification of the growth stage and drought degree of pakchoi.The results obtained from the laboratory experiments also provide a basis for the use of spaceborne data.