【摘要】 【目的】呼伦贝尔地区降水量少,年际和年内分布不均,灌溉条件不发达,干旱对当地农业和畜牧业生产造成了严重影响,结合干旱监模型与荧光数据可对呼伦贝尔干旱情况进行有效监测。【方法】文章使用MODIS归一化植被指数(NDVI)和地表温度(LST)产品,建立Ts-NDVI特征空间,计算温度植被干旱指数(TVDI),同时结合GOME-2 L2级荧光产品,综合分析评价2017—2018年呼伦贝尔地区干旱时空变化特征。【结果】该文建立的干旱指数模型能有效监测呼伦贝尔市干旱状况,干旱等级划分结果表明,2017—2018年呼伦贝尔地区存在不同程度的干旱问题,此模型在该研究区干旱监测上具有很好的适用性;通过SIF与NDVI的变化过程对比分析发现,SIF对水分胁迫等植被生理变化比较敏感,SIF较NDVI而言,能更有效地反映植物受胁迫状况。【结论】通过MODIS产品与GOME-2 L2荧光产品相结合,可以更准确地监测分析该研究区内的干旱时空动态变化,为呼伦贝尔市的旱情监测提供重要参考。更多还原

【Abstract】 [Purpose]Drought,as the most common and widespread natural disaster in the world,occurs frequently and always lasts for a long time. Usually,the economic losses and impacts caused by drought far exceed those of other meteorological disasters. The Hulunbeier area has less precipitation,uneven distribution of precipitation,and underdeveloped irrigation conditions. Drought has seriously affected local agriculture and animal husbandry production.[Method]In this work,MODIS normalized vegetation index(NDVI)and surface temperature(LST)products were used to establish the Ts-NDVI feature space,Simultaneously,The Temperature Vegetation Dryness Index(TVDI)was calculated. Combining GOME-2 L2 grade fluorescent products,we comprehensively analyzed and evaluated the temporal and spatial variation characteristics of drought in Hulunbeier area from 2017 to 2018.[Result]The drought index model established in this paper can effectively monitor the drought situation in Hulunbeier City. Our division of drought grades indicate that there are different degrees of drought in the Hulunbeier area from 2017 to 2018. This model has a good applicability for drought monitoring in this study area. Comparing the changes of SIF and NDVI,we found that SIF is more sensitive to vegetation physiological changes such as water stress. Additionally,SIF can reflect the stress status of plants more effective than NDVI.[Conclusion]The combination of MODIS products and GOME-2 L2 fluorescent products can monitor and analyze the dynamic changes of drought in our study area accurately. This provides an important reference for drought monitoring and early warning in Hulunbeier City.更多还原