摘要
通过冬小麦生育期的水分控制试验,利用便携式野外光谱仪(ASD FieldSpec 3)测量冬小麦的光谱,根据8个水分指数公式分别计算水分指数,并同时测定冬小麦的冠层叶片含水率和土壤含水率。结果表明,整个生育期内,冠层叶片含水率及土壤含水率与各水分指数的相关性呈先增大后减小的趋势,抽穗期、灌浆期及乳熟期是冠层叶片含水率及土壤含水率的最佳监测生育期。低覆盖度情况下,植被水分指数更多反映的是土壤水分状况;随着覆盖度的增大,植被水分指数对冠层叶片含水率比对土壤含水率的监测效果更好、覆盖时间更长。在最佳监测生育期,近红外(NIR)和波红外(SWIR)归一化型的水分指数对叶片含水率的监测效果较好,而近红外(NIR)简单比值型的水分指数对植被覆盖情况下的土壤含水率监测效果较好。
Through the experiment with soil moisture controlled in the whole growth season, the spectral data of winter wheat were obtained using the portable field spectrometer （ASD FieldSpec 3 U S A）, moisture indexes were calculated using 8 different moisture indices equations. Meanwhile, leaf water content of winter wheat and soil moisture were calculated. The results showed that： the correlation between canopy leaf water content/soil water content and each moisture index increased first and decreased afterwards in the whole growth season. The canopy leaf water content and soil water content could he well monitored in the heading stage, milk-filling stage and milk stage. Under low coverage, the moisture index had a higher correlation with soil moisture compared to canopy leaf water content. As the coverage increased, the leaf water content could be monitored more efficiently and the coverage time was longer by vegetation water index. In the best monitoring growth periods, the near-infrared（NIR） and shortwave infrared（SWIR） normalized moisture index had better monitoring effects on leaf water content, meanwhile, while the near-infrared（NIR） simple ratio-type moisture index had a better monitoring effect on soil moisture in case of vegetation cover.
出处
《灌溉排水学报》
CSCD
北大核心
2014年第4期213-217,共5页
Journal of Irrigation and Drainage
基金
国家自然科学基金项目(51179162)
关键词
高光谱遥感
叶片含水率
土壤含水率
植被水分指数
Hyperspectral remote sensing
leaf water content
soil moisture
vegetation moisture index
