基于GRACE与MODIS的海河流域干旱监测与分析

Drought Monitoring and Analysis over Haihe River Basin Based on GRACE and MODIS Datasets

海河流域作为中国重要流域之一,其干旱形势影响着该流域内工农业生产与人民生活。利用海河流域2003—2015年GRACE(Gravity Recovery and Climate Experiment)重力卫星数据、MODIS数据以及同期23个站点降水量和蒸发量数据,分析了海河流域地下水资源变化以及地表植被覆盖度的时空演变特征,并采用TOPSIS客观赋权法(Technique for Order Preference by Similarity to Ideal Solution)建立干旱综合指数评价模型。研究发现海河流域等效水高表现出明显的周年变化,总体呈下降趋势;NDVI在时间序列上表现出较强的季节相关性,在空间序列上表现出西北—东南向的条带状分布;2003—2015年海河流域有轻微干旱,其中2014年干旱情况最为严峻。从空间分布来看,夏季干旱趋势主要集中于大清河系及永定河北部,春秋季主要集中于滦河河系及漳卫河系。通过与SPEI(Standardized Precipitation Evapotranspiration Index)指数对比,验证了该干旱综合指数模型有较好的可用性。研究成果可为海河流域水资源干旱监测提供参考。

The Haihe River Basin is one of the most important watersheds in China,and its drought situations affect the industrial and agricultural production and people's lives in the region.This paper analyzes the spatial and temporal evolution characteristics of groundwater and surface vegetation coverage in the Haihe River Basin with the GRACE(Gravity Recovery and Climate Experiment)data,MODIS data,precipitation and evaporation data of 23 sites from 2003 to 2015,and builds a drought comprehensive index evaluation model by TOPSIS(Technique for Order Preference by Similarity to Ideal Solution)method to reflect the drought dynamics.The results show that:The water height of the Haihe River Basin indicates a significant annual change with a general downward trend;NDVI(Normalized Difference Vegetation Index)shows a strong seasonal correlation in the time series,and shows a northwest-southeast band distribution in the spatial series;There was a slight drought in the Haihe River basin between 2003 and 2015,of which 2014 was the most severe;In terms of spatial distribution,the drought mainly occurs in the Daqing River and the northern part of Yongding River in summer,while in Luanhe River and Zhangwei River in spring and autumn.Through comparison with the SPEI(Standardized Precipitation Evapotranspiration Index),it is verified that the drought comprehensive index model has good availability.The research can provide a valuable reference for water resources drought monitoring in the Haihe River Basin.