基于大气-土壤-植被系统干旱发生发展过程的综合干旱指标构建与应用

适宜的干旱指标和高分辨率数据是准确监测干旱的基础。本研究从气象干旱和土壤干旱以及植被对干旱的响应出发，整合中国国家气象观测站、中国气象局陆面数据同化系统（CLDAS）土壤湿度（0.0625°×0.0625°）和MODIS叶面积指数（500 m×500 m）等多源数据信息，构建了基于气象干旱指数（标准化降水蒸散指数）、土壤干旱指数（土壤湿度百分位）和植被干旱指数（叶面积指数百分位）的综合干旱指数，并在中国东北地区开展了典型站点和区域10 km×10 km空间分辨率干旱监测试验。结果表明，综合干旱指数克服了单一气象干旱指数不能准确反映农业旱情及单一植被长势指数会将其他灾害引起的植被长势变差误判为干旱的不足，能够反映灌溉对干旱的影响，实现对大气-土壤-植被系统干旱发生、发展及其影响的监测。 

Construction and application of the combined drought index based on the development process of drought in the atmosphere-soil-vegetation system

An appropriate drought index and high-resolution data are the basis of accurate and precise drought monitoring. In this study, we constructed a Combined Drought Index (hereafter CDI) based on the response relationships between meteorological drought (SPEI), soil drought (SMP) and vegetation drought (LAIP) using integrated multisource data of China National Meteorological Observatory, Soil Moisture of CMA Land Data Assimilation System with 0.0625°×0.0625° resolution and MODIS LAI with 500 m×500 m resolution. The monitor results of CDI were assessment at station scale and regional scale with 10 km×10 km resolution in Northeast China. The results show that CDI overcomes the shortcomings of single meteorological drought index, which cannot accurately reflect agricultural drought. The misjudgment that attributes the vegetation growth variation caused by other disasters to drought based on single vegetation growth index is corrected. The CDI can reflect the effects of irrigation on drought and monitor the occurrence and development of drought and its impact on crops and other vegetation growth. The above results indicate that CDI classification monitoring results have a clear biophysical significance, a fine spatial resolution and a strong practical guidance. It has application potentials in the monitoring, assessment and prediction of drought occurrence and development and drought impact on agriculture and other green vegetations.