Water storage depletion is an increasing hydrological threat to agricultural production and social stability across the globe. It is fast approaching threshold levels especially in arid/semiarid regions with low precipitation and excessive evapotranspiration (ET).

The research group headed by Prof. TAO Fulu in Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, analyses water storage dynamics in the North China Region (NCR) – an important grain-production base in China. In the NCR, water supply for the over 686 million people, as well as the vast agricultural fields and huge industries, depends on highly intensive water resources exploitation.

They use monthly Gravity Recovery and Climate Experiment (GRACE), Global Land Data Assimilation System (GLDAS) and field-measured precipitation data products for 2002–2009. The datasets are analyzed in a basin-scale water balance equation to determine the state of storage in the NCR study area. Based on the validated satellite-based data products with field-measured values, average error/bias in the datasets is <10%.

The analysis also shows favorable agreements among the GRACE-derived and flux-based water storage changes at various temporal scales. Whereas the amplitudes and phases of the precipitation and ET fluxes are largely stable for 2002–2009, those of GLDAS runoff and GRACE total water storage anomaly apparently narrow out. The linear trends in the monthly, seasonal and annual storage changes are negative for the study period, suggesting water storage loss. There is an apparent seasonality of storage change in the study area; with summer storage gain, winter storage loss and an overall storage loss that is on the average of 16.8 mm/yr. Storage loss is most severe in the central floodplain region (the main irrigated production zone) of the study area.

Time-series comparisons of total water storage change (TWSC) derived from Gravity Recovery and Climate Experiment (GRACE) with that derived from meteorological data at monthly (a), seasonal (b), average monthly (c), average seasonal (d) and annual (e) cycles for the North China Region study area (Imaged by TAO Fulu )

Papers：

1. Moiwo Juana Paul, Tao Fulu*, Lu Wenxi. 2012.Analysis of satellite-based and in situ hydro-climatic data depicts water storage depletion in North China Region.Hydrological Processes, doi:10.1002/hyp.9276.

2. Moiwo Juana Paul, Lu Wenxi, Tao Fulu*. 2012.GRACE, GLDAS and measured groundwater data products show water storage loss in Western Jilin,China.Water Science and Technology, 65(9):1606-1614.

3. Moiwo Juana Paul, Tao Fulu*, Lu Wenxi. 2011.Estimating soil moisture storage change using quasi-terrestrial water balance method.Agricultural Water Management, 102:25-34.

4. Tao Fulu*, Z. Zhang. 2011. Dynamic Response of Terrestrial Hydrological Cycle and Plant Water Stress to Climate Change in China. Journal of Hydrometeorology, 12, 371-393, doi: 10.1175/2010JHM1314.1.