基于GRACE和MODIS数据的长江流域陆地水储量变化分析及预测

Analysis and Prediction of the Anomaly of Terrestrial Water Storage in the Yangtze River Basin Based on MODIS and GRACE

利用GRACE重力卫星数据反演的长江流域陆地水储量变化(TWSA)以及MODIS遥感数据生成的归一化植被指数(NDVI),从趋势性、相关性及时空变化特征3方面分析长江流域陆地水储量变化以及植被覆盖变化。结果表明:长江流域归一化植被指数(NDVI)与陆地水储量变化(TWSA)之间有强相关性,二者均在2月份达到最低值,在8月份达到峰值,季节变化均呈现夏季>秋季>春季>冬季的规律。利用GRACE水储量与NDVI最小二乘拟合关系,通过灰色预测模型得出长江流域2016年为偏丰水年。研究结果可为长江流域水资源规划及预警提供参考依据。

According to the terrestrial water storage anomaly（ TWSA） inversed by GRACE（ Gravity Recovery and Climate Experiment） satellite data and normalized difference vegetation index（ NDVI） generated by MODIS remote sensing satellite in Yangtze River basin,the variations of terrestrial water storage and vegetation cover in the Yangtze River Basin are analyzed from aspects of trend,correlation,temporal and spatial variation characteristics. Results indicate strong correlation between TWSA and NDVI,which both reach the minimum in February and the maximum in August; the values of TWSA and NDVI are greatest in summer,followed by those in autumn,spring,and winter in sequence. By least square fitting between TWSA and NDVI together with grey prediction model,we conclude that in the Yangtze River Basin 2016 is the relatively wet year. The results would offer reference for the planning and pre-warning of water resources in the Yangtze River basin.