中文摘要：

基于风云3号（FY-3）卫星中分辨率成像光谱仪（medium resolution spectral imager,MERSI）数据的归一化差异水体指数（normalized difference water index,NDWI）和基于蓝光波段的归一化差异水体指数（normalized difference water index based on blue light,NDWI-B）,通过直方图分析获取了水体指数判识阈值,并对新疆北疆沿天山一带2009—2011年发生的融雪性洪水灾害天气进行了监测。对比基于环境1号卫星CCD数据的监测结果表明：利用FY-3/MERSI的250 m空间分辨率数据可实现对新疆融雪性洪水灾害的监测,其中利用FY-3/MERSI NDWI-BFY数据的判识效果最好。

英文摘要：

On the basis of normalized difference water index （ NDWI） of FY-3/medium resolution spectral imager （ MERSI） and normalized difference water index based on blue light （ NDWI-B） , the authors analyzed histograms and obtained the thresholds for the recognition of water bodies with NDWI. The thresholds were utilized in the monitoring of the snowmelt flood disaster along the Tianshan Mountains in the north of Xinjiang during 2009 to 2011 . The results achieved by the authors suggest that it is feasible to monitor the snowmelt flood disaster in Xinjiang with the data both from FY -3/MERSI and from HJ -1A /CCD. The effect of using FY -3/MERSI （NDWI-BFY） data to identify large area of flood water is the best.