基于GRACE/GRACE-FO数据降尺度方法反演库尔勒东区地下水储量变化  

Retrieval of groundwater storage anomalies in eastern region of Korla by downscaling GRACE/GRACE-FO data

作　　者：刘东旭[1] 胡立堂[2,3] 孙建冲 程琦 马艺瑄 刘鑫 LIU Dongxu;HU Litang;SUN Jianchong;CHENG Qi;MA Yixuan;LIU Xin(Northwest Institute of Nuclear Technology,Xi an 710024,China;College of Water Sciences,Beijing Normal University,Beijing 100875,China;Engineering Research Center of Groundwater Pollution Control and Remediation,Ministry of Education,Beijing100875,China;PowerChina Huadong Engineering Corporation Limited,Hangzhou 311122,China)

机构地区：[1]西北核技术研究所,陕西西安710024 [2]北京师范大学水科学研究院,北京100875 [3]地下水污染控制与修复教育部工程研究中心,北京100875 [4]中国电建集团华东勘测设计研究院有限公司,浙江杭州311122

出　　处：《测绘学报》2024年第7期1265-1277,共13页Acta Geodaetica et Cartographica Sinica

基　　金：国家自然科学基金联合基金(U216720006)。

摘　　要：GRACE与GRACE-FO重力卫星为全球中大尺度地下水反演监测提供了新的手段,但难以提供小尺度上较高空间分辨率的地下水储量变化(GWSA)信息。本文针对新疆库尔勒东部缺资料区,采用动力降尺度方法提高GRACE/GRACE-FO反演GWSA数据的空间分辨率,分析GWSA的时空分布规律。首先,基于数据融合方法构建了库尔勒东区GWSA数值模型;然后,利用优化后的模型将GWSA反演数据的分辨率从1°降尺度至0.25°和0.05°,将反演的GWSA与水井监测的地下水位(GWL)数据进行对比验证;最后,利用0.05°GWSA数据分析研究区GWSA态势。结果表明:①与降尺度前1°GWSA数据相比,降尺度转换后的高分辨率GWSA数据在空间上更加平滑、展示了更加丰富的细节,且提高了与水井GWL监测数据的相关性,改进了反演精度和可靠性;②小尺度上,降尺度后的GWSA数据能够反映水源地地下水的季节性、年际和长期开采下的亏损等动态特征;③研究区GWSA呈现出时空分布差异性,2005—2020年区内地下水储量变化率为-1~1 mm·a-1,总体上呈南增、北减态势,南、北部山区的变幅大于中部相对平坦区域。Despite the gravity recovery and climate experiment(GRACE)and GRACE follow-on(GRACE-FO)satellites provide a new capability for retrieving and monitoring of global large-scale groundwater storage anomaly(GWSA),its data products struggle to provide access to small-scale GWSA information with high spatial resolution.In this paper,a dynamic downscaling method was employed to improve the spatial resolution of GWSA data retrieved by GRACE/GRACE-FO and to analyse the spatio-temporal distribution of GWSA in the eastern area of Korla,Xinjiang,China.Firstly,a GWSA numerical model of eastern region of Korla was constructed and optimized based on data fusion for purposes of the spatial downscaling conversion.Then,the resolution of GRACE/GRACE-FO-derived GWSA data was downscaled from 1°to 0.25°and 0.05°via the optimized model.The derived GWSA results were further compared with the well-monitored groundwater level(GWL)data.Finally,the GWSA trends in specific study areas were evaluated using 0.05°GWSA data.Specific results include:①Compared to the 1°GWSA without downscaling transformation,the high-resolution GWSA data after downscaling are spatially smoother and more detailed,whose correlation with the GWL monitoring data is increased,indicating an improvement in inversion accuracy and reliability.②At small scales,the downscaled GWSA can reflect the groundwater regime,such as seasonal and interannual variations,as well as long-term depletion,in specific water sources.③The GWSA in the eastern area of Korla states the characteristics of spatial and temporal differences,whose trends from 2005 to 2020 are-1~1 mm·a-1,generally following an increasing tendency in the south and a decreasing tendency in the north.Specifically,the GWSA slopes in the southern and northern mountainous zones are greater than those in the relatively flat central region.

关 键 词：GRACE 地下水储量变化 动力降尺度 地下水模型 数据融合 

分 类 号：P258[天文地球—测绘科学与技术]