Reply to Zhang et al.: Using long-term all-available Landsat data to study water bodies over large areas represents a paradigm shift

Zhang et al. (1) raise concerns over the characteristics and change of surface water bodies (WBs) in China reported in our article in PNAS (2). We believe these concerns are not well grounded. The dynamic nature of WBs results in a constant change in their number and extent over large land areas. Therefore, it is important to define a temporal window from whence the WB calculations are referenced, as Zhang et al. (1) highlight. Feng et al. (2) reference previous studies that relied on satellite snapshots acquired at one, or a few, points in time to study WBs across China. These studies, while useful for characterizing WB conditions at the specific points in time, could not accurately estimate the maximum extent, … [↵][1]1To whom correspondence may be addressed. Email: shuguang.liu{at}yahoo.com. [1]: #xref-corresp-1-1