High-temporal-resolution water level and storage change data sets for lakes on the Tibetan Plateau during 2000–2017 using multiple altimetric missions and Landsat-derived lake shoreline positions

摘要

Abstract. The Tibetan Plateau (TP), known as Asia's water tower, isquite sensitive to climate change, which is reflected by changes in hydrologic statevariables such as lake water storage. Given the extremely limited groundobservations on the TP due to the harsh environment and complex terrain, weexploited multiple altimetric missions and Landsat satellite data to createhigh-temporal-resolution lake water level and storage change time series atweekly to monthly timescales for 52 large lakes (50 lakes larger than 150 km~(2) and 2 lakes larger than 100 km~(2)) on the TP during 2000–2017. The data sets are available online at https://doi.org/10.1594/PANGAEA.898411 (Li et al., 2019). WithLandsat archives and altimetry data, we developed water levels from lakeshoreline positions (i.e., Landsat-derived water levels) that cover thestudy period and serve as an ideal reference for merging multisource lakewater levels with systematic biases being removed. To validate theLandsat-derived water levels, field experiments were carried out in twotypical lakes, and theoretical uncertainty analysis was performed based onhigh-resolution optical images (0.8 m) as well. The RMSE of theLandsat-derived water levels is 0.11 m compared with the in situmeasurements, consistent with the magnitude from theoretical analysis(0.1–0.2 m). The accuracy of the Landsat-derived water levels that can bederived in relatively small lakes is comparable with most altimetry data.The resulting merged Landsat-derived and altimetric lake water levels canprovide accurate information on multiyear and short-term monitoring of lakewater levels and storage changes on the TP, and critical information on lake overflow flood monitoring and prediction as the expansion of some TP lakesbecomes a serious threat to surrounding residents and infrastructure.