基于遥感DSI指数的干旱与冬小麦产量相关性分析

利用2000—2012年MODIS ET/PET和NDVI数据集构建干旱指数(DSI),监测山东省和河南省冬小麦主产区的农业干旱,并在地级市尺度上进一步评估冬小麦关键生育期干旱对冬小麦产量的影响。结果表明:2010年9月—2011年2月山东省特大干旱过程显示的DSI不仅能监测气象干旱,还能较好地反映农业干旱在空间上的差异性以及时间上的演变。不同冬小麦生育期干旱对冬小麦产量影响不同,灌浆期干旱对冬小麦产量的影响最大,干旱致使土壤水分亏缺,影响了作物正常的灌浆强度,进而导致作物减产;其次是拔节期;返青期干旱对产量基本没有影响。

Correlation Analysis between Drought and Winter Wheat Yields Based on Remotely Sensed Drought Severity Index

Drought is one of the most important agricultural meteorological disasters in China, resulting in significant impacts on winter wheat growth and yield. Satellite remote sensing can provide real time and dynamic surface information and has become an effective tool for regional agricultural drought monitoring. In this study, the drought severity index (DSI) was first computed based on MODIS ET/PET and NDVI dataset from 2000 to 2012 for agricultural drought monitoring at prefecture-city level in winter wheat producing areas of both Shandong province and Henan province, and further evaluated the influence of agricultural drought on winter wheat yield during key phenological periods. The main conclusions from the study are as follows: the results from the Shandong province droughts occurring from September 2010 to February 2011 showed that DSI can not only monitor meteorological drought but can also reflect the spatial variations and temporal evolution for agricultural drought. Drought has varying impacts on winter wheat yield during different phenological stage of the growing season. Generally, the filling stage of winter wheat has the most important impact on winter wheat yield, during which drought induced soil water deficit affects the crops normal grouting intensity and results in reduction of winter wheat yield. The jointing stage follows and drought has negligible effect on winter wheat yield during the green up stage. The research can provide important reference for agricultural drought monitoring and drought impacts on crop yield in other agricultural regions.