基于GRACE及GRACE-FO重力卫星的北方寒区干旱分析与评估

Drought analysis and assessment based on GRACE and GRACE-FO gravity satellites in cold regions of northern China

中国北方寒区水资源紧缺、干旱事件频发,研究一种准确高效干旱监测方法尤为重要。研究利用GRACE及GRACE-FO重力卫星数据计算得到一种标准化水储量赤字指数(GRACE-DSI),据此对北方寒区2002~2022年干旱事件进行量化,探究其干旱变化特征。结果表明,2002~2022年研究区内共发生8次干旱事件,其中2007年7月至2009年12月干旱事件历时最长、旱情最为严重且波及面积最广。GRACE-DSI监测结果与现有记载吻合程度高,可准确监测干旱事件发生节点、持续时间与严重程度,与PDSI、SPI、SPEI等传统干旱指数相比具有良好一致性。因此,GRACE-DSI对于推动北方寒区干旱监测研究进展意义重大,在跨流域尺度干旱监测方面优势显著,同时为水资源优化配置、农业生产水量调配、生态水环境治理提供科学依据。

Research into an accurate and efficient method for drought monitoring was particularly important in the cold regions of northern China where water resources were scarce and droughts were frequent.GRACE and GRACE-FO data were combined to estimate deficit storage index(GRACE-DSI).It enabled quantification and detection of drought events in the northern cold regions from 2002 to 2022.The results showed that eight drought events occurred in the cold regions of northern China from 2002 to 2022.The most severe,prolonged and expansive drought events occurred from July 2007 to December 2009.Drought events monitored by GRACE-DSI were consistent with available records.GRACE-DSI could accurately monitor the occurrence nodes,duration and severity of drought events.Additionally,it also had consistence with traditional drought indices such as PDSI,SPI and SPEI.GRACE-DSI was significant for promoting the progress of drought monitoring researches in the cold regions of northern China.It was also important for drought monitoring on cross-basin scale,water resource optimization allocation,agricultural production water allocation,and ecological water environment management.