基于CLDAS资料的内蒙古干旱监测分析

以内蒙古地区为研究区域，对中国气象局陆面数据同化系统（CMA Land Data Assimilation System，CLDAS）的土壤湿度和降水数据进行了评估，使用土壤相对湿度法和连续无降水日数法监测2014年夏季干旱，并选择干旱年（2014年）和湿润年（2013年）与标准化降水指数和降水百分位指数法进行验证分析。结果表明：CLDAS资料能够很好地再现日土壤相对湿度动态变化情况和降水落区与量级，能够满足干旱监测的需求；基于CLDAS数据的土壤相对湿度法可以方便、快捷地监测干旱日变化和区域性变化，连续无有效降水日数法对评估长时间、持续性干旱较为有效；CLDAS同化数据在时效性、分辨率、代表性上能够满足气象服务的需求，可作为观测资料的重要补充广泛应用于业务和科研，特别是对于地广人稀且气象站点相对较少的内蒙古地区气象服务潜力巨大。

Analysis of Drought Monitoring in Inner Mongolia Based on CLDAS Data

The soil moisture and precipitation data of Inner Mongolia of CMA Land Data Assimilation System (CLDAS) were evaluated. The drought that happened in Inner Mongolia in the summer of 2014 was analyzed using CLDAS with RSM and DNP, and the results of dry year (2014) and wet year (2013) were compared with SPI and PDECI. The analysis results revealed that the dynamic variation of daily soil relative moisture and the precipitation area and grade can be reconstructed by CLDAS, which can meet the requirements of drought monitoring. The soil relative moisture index based on CLDAS can monitor the daily and regional changes of drought of quickly and conveniently. The continuous absence of effective precipitation day is relatively valid for estimating long period and continuous drought. In brief, CLDAS is able to fulfill the timeliness, resolution and representativeness requirements of meteorological service, and can serve research and operation widely as important supplementary for monitoring data. It is valuable for areas like Inner Mongolia where weather station is relatively scarce in a widespread area.