Assessment of Water Storage Change in China’s Lakes and Reservoirs over the Last Three Decades

Abstract

Lakes and reservoirs are essential elements of the hydrological and biochemical cycles, considered sentinels of global climate change. However, comprehensive quantifications of their water storage changes (∆V) at a large spatiotemporal scale are still rare. Here, we integrated a global surface water dataset and SRTM digital elevation models, both available from Google Earth Engine platform at a spatial resolution of 30 m, to evaluate ∆V for a total of 760 lakes and reservoirs across China at an annual timescale since 1984. The results indicated that (1) the aggregated water storage went through a slight increase of 41.5 Gt (1.7 Gt/yr) during 1985-2005, a significant decrease of 100 Gt (−20.6 Gt/yr) during 2005-2009, and then increased by 136.3 Gt (21.3 Gt/yr) during 2009-2015.(2) The increasing trend was largely attributed to lakes and reservoirs in the Tibetan Plateau Lake Zone, and the decreasing trend was mainly due to the North and Northwest Lake Zone, with little variations observed for the Northeast and Southwest Lake Zones. (3) Qinghai lake was associated with the largest increase (18.3 Gt) and Poyang lake presented the largest decline (−9.2 Gt). The results can help advance our understanding of the impact of climate change and improve future projection.Water storage changes in lakes and reservoirs present significant spatial and temporal variability, reflecting heterogeneity of local conditions in terms of climate, hydrology, topography, land cover and human disturbance. Monitoring water storage change can help to understand the dynamics of the global hydrological cycle and predict the impact of global changes on water resources [5]. Assessing water storage changes in lakes and reservoirs is consequently becoming increasingly important for the sustainable management of water resources. Limitation of Current AssessmentsHowever, until now, the spatio-temporal characteristics of water storage change have remained inadequately assessed. Comprehensive quantifications of water storage change in lakes and reservoirs are still lacking at the large spatial and temporal scales [6,7]. Spatially, the existing assessments are mainly concentrated on: (1) large lakes such as Qinghai Lake [8,9], Poyang Lake [10], and Lake Victoria [5]; (2) a small number of lakes and reservoirs, for example, 11 large lakes in South Tibet [4], 27 reservoirs in South Asia [11], 30 lakes in Tibetan Plateau [12], and 114 lakes larger than 50 km 2 in Tibetan Plateau [13]; (3) specific regions such as the Tibetan Plateau, due to its unique climatic and topographic condition, significant ecological effects, and sensitive responses to climate change [14,15], accumulating a series of important research findings [7,12,[14][15][16][17][18]. Long-term analyses can enrich our knowledge about the history and current situation of lakes and reservoirs and advance our understanding of the mechanism of water storage change [5]. Yet, current assessments have been limited to a short time period, including analyses at several time points [12] and analyses ov...

Seasonal Amplitude of Water Storage Variations of the Yangtze–Huai Plain Lake Group: Implicaion for Floodwater Storage Capacity

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Quantifying Turbidity Variation for Lakes in Daqing of Northeast China Using Landsat Images From 1984 to 2018

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The Decrease in Lake Numbers and Areas in Central Asia Investigated Using a Landsat-Derived Water Dataset

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