Characterizing Drought and Flood Events over the Yangtze River Basin Using the HUST-Grace2016 Solution and Ancillary Data

Abstract

Accurate terrestrial water storage (TWS) estimation is important to evaluate the situation of the water resources over the Yangtze River Basin (YRB). This study exploits the TWS observation from the new temporal gravity field model, HUST-Grace2016 (Huazhong University of Science and Technology), which is developed by a new low-frequency noise processing strategy. A novel GRACE (Gravity Recovery and Climate Experiment) post-processing approach is proposed to enhance the quality of the TWS estimate, and the improved TWS is used to characterize the drought and flood events over the YRB. The HUST-Grace2016-derived TWS presents good agreement with the CSR (Center for Space Research) mascon solution as well as the PCR-GLOBWB (PCRaster Global Water Balance) hydrological model. Particularly, our solution provides remarkable performance in identifying the extreme climate events e.g., flood and drought over the YRB and its sub-basins. The comparison between GRACE-derived TWS variations and the MODIS-derived (Moderate Resolution Imaging Spectroradiometer) inundated area variations is then conducted. The analysis demonstrates that the terrestrial reflectance data can provide an alternative way of cross-comparing and validating TWS information in Poyang Lake and Dongting Lake, with a correlation coefficient of 0.77 and 0.70, respectively. In contrast, the correlation is only 0.10 for Tai Lake, indicating the limitation of cross-comparison between MODIS and GRACE data. In addition, for the first time, the NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) vertical velocity data is incorporated with GRACE TWS in the exploration of the climate-induced hydrological activities. The good agreement between non-seasonal NCEP/NCAR vertical velocities and non-seasonal GRACE TWSs is found in flood years

Identifying Flood Events over the Poyang Lake Basin Using Multiple Satellite Remote Sensing Observations, Hydrological Models and In Situ Data

“…As the groundwater and surface component are also included, the greater amplitude of TWS variations (see Figure 7 and Table 2) is observed in PCR-GLOBWB. It demonstrates the extreme contribution of surface water and groundwater component to TWS over Poyang Lake basin [11]. Comparing the TWS variations derived from PCR-GLOBWB and PCR-GLOBWB(SM), the long-term positive TWS anomalies in Figure 6 are always corresponding to the big discrepancies between these two time series in Figure 7.…”

“…The good agreement justifies the usage of the PCR- Figure 7 and Table 2) is observed in PCR-GLOBWB. It demonstrates the extreme contribution of 338 surface water and groundwater component to TWS over Poyang Lake basin [11]. Comparing the…”

“…Multiple remote sensing observations have been used to identify the flood events over the Poyang Lake [5][6][7][8]. Among these, the Moderate Resolution Imaging Spectroradiometer (MODIS) [9] can quantify the variation of the inundated area [5,10,11]; the altimetry satellites can detect the water level variations of the lake [12]; and the Tropical Rainfall Measuring Mission (TRMM) [13] can monitor the temporal variations of precipitation. However, these missions are not able to detect the total terrestrial water storage (TWS) variations, which is crucial for the analysis of the extreme hydrological activities [14][15][16][17][18].…”

HUST-GOGRA2018s: A new gravity field model derived from the combination of GRACE and GOCE data

“…Based on this study, we deduced the mathematical calculation formulas of these two different low-frequency noise processing strategies in Zhou et al (2017a), and a new strategy was created to simultaneously filter the design matrix and observation vector of observation equation. Using this new strategy, we have developed a new time series of monthly gravity field models HUST-Grace2016 (Zhou et al 2017b), which have good agreement with CSR Release05, JPL Release05, and GFZ Release05. In this study, we also make use of this new processing strategy to remove the low-frequency noise in range rate residuals.…”

An Improved Approach for Evapotranspiration Estimation Using Water Balance Equation: Case Study of Yangtze River Basin

“…In recent years, the GRACE temporal gravity field models have been applied to the present-day mass redistribution within the earth system [18], covering global and local hydrological cycles [19,20], glacial mass variations [21,22], global sea level change [23,24] (Cazenave et al 2009, and coseismic deformation [25][26][27]. Initially, research on TWS variations focused primarily on the level of agreement between hydrological models and GRACE-derived results, or on the detection of TWS anomalies caused by extreme climatic events [28][29][30] or human activity [31][32][33]. The long-term GRACE dataset has allowed recent applications of GRACE-derived water storage variations to consider estimations of important components of the hydrological cycle, such as ET [10,11,14] and river discharge, to calibrate hydrological models [34,35], or to improve LSMs [36,37].…”