Acta Geodaetica et Cartographica Sinica ›› 2023, Vol. 52 ›› Issue (11): 1883-1891.doi: 10.11947/j.AGCS.2023.20220484

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A drought index derived from a combination of GNSS GRACE/GRACE-FO and meteorological data

YAO Chaolong1,2,3, CHEN Yongxin1, LUO Zhicai4, LI Qiong5, YE Xuemiao1, WEN Jinjie1   

  1. 1. College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China;
    2. Key Laboratory of the Ministry of Land and Resources for Construction Land Transformation, South China Agricultural University, Guangzhou 510642, China;
    3. Guangdong Province Land Information Engineering Technology Research Center, South China Agricultural University, Guangzhou 510642, China;
    4. MOE Key Laboratory of Fundamental Physical Quantities Measurement, Institute of Geophysics and PGMF, School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China;
    5. School of Civil Engineering and Geomatics, Southwest Petroleum University, Chengdu 610500, China
  • Received:2022-08-02 Revised:2023-07-03 Published:2023-12-15
  • Supported by:
    The National Natural Science Foundation of China (No. 42004013);Guangdong Basic and Applied Basic Research Foundation (No. 2022A1515010469);Guangzhou Science and Technology Project (Nos. 202102020526;202102020380)

Abstract: Developing the combined drought index (CDI) integrating multi-source data is of important significance for accurate, objective and comprehensive drought monitoring and assessment. In this study, we built a novel CDI reflecting hydro-meteorological variables in Southwest China based on the principle component analysis. The proposed CDI integrates drought indices derived from Global Navigation Satellite System (GNSS) vertical displacements and time-variable gravity fields from Gravity Recovery and Climate Experiment (GRACE)/GRACE Follow-On (GRACE-FO) as well as the commonly used meteorological composite index (CI) in China. The results show that compared to the individual CI index and the drought indices based on GNSS, GRACE/GRACE-FO data, correlation coefficients between the proposed CDI and self-calibrating palmer drought severity index (scPDSI) improved significantly, with the maximum value of 0.84; the number of sites with improved correlations for the individual drought indices account for 100%, 93%, and 67%, respectively;the averaged correlation coefficients of all studied sites increased from 0.48, 0.34, 0.57 to 0.64, respectively. The results indicate the effectiveness of integrating drought information containing in multi-source data in the proposed CDI index, which could help to improve regional drought monitoring.

Key words: GNSS, GRACE/GRACE Follow-On, data fusion, drought index, principle component analysis

CLC Number: