A new method for estimating the annual evaporation of the "Asian Water Tower" proposed by the Qinghai-Tibet Plateau

[ Instrument R&D of instrument network ] Using the reasonable assumption of the energy balance of the Qinghai-Tibet Plateau lake during the non-icing period, combined with remote sensing data and re-analysis data, Ma Yaoming, a researcher of the Geogas and Climate Change team at the Qinghai-Tibet Plateau Research Institute of the Chinese Academy of Sciences, has developed a reliable The method of lake evaporation estimation, and the total amount of lake evaporation in the Qinghai-Tibet Plateau is estimated to be 51.7 billion tons per year, which is equivalent to the water volume of 3570 West Lakes in Hangzhou, providing data reference for accurately estimating the lake water resources in the "Asian Water Tower". Related results were published in "Science-Progress".

The Qinghai-Tibet Plateau is called the "Asian Water Tower", and its lake area is nearly 50,000 square kilometers, accounting for more than 50% of the total lake area in China. In previous studies on lake water cycling in the Qinghai-Tibet Plateau, few observations have been made on lake-gas interactions in high-altitude lakes. The lake evaporation obtained by different research methods in the same lake has obvious differences, and the spatial distribution of the lake evaporation and the total evaporation are still unknown.

This study is based on the reasonable assumption of the energy balance of the Tibetan Plateau lakes during the non-icing period, combined with satellite remote sensing data, Chinese meteorological driving data set data, and observation data of the Qinghai-Tibet Plateau Observation and Research Platform to obtain the icing process and lake evaporation of 75 large lakes on the Tibetan Plateau. Data such as the spatial distribution of the quantity and the total amount of lake evaporation. By comparing with the measured results, the research results show good consistency.

The comprehensive results show that the total evaporation of lakes on the Tibetan Plateau is 517±2.1 billion tons per year, and the total evaporation of 75 large lakes is 294±1.2 billion tons per year. The ice sublimation water in the lake in winter accounts for about 12.3% to 23.5% of the annual evaporation of the lake, which is an important part of the study of the lake water balance. The length of the non-icing period and the evaporation of the lake in the southern Tibetan Plateau are significantly higher than those in the northern lake. The new method used in this study can accurately estimate lake evaporation in the Tibetan Plateau and can be used to estimate lake evaporation in other parts of the world.

The research was funded by the Second Comprehensive Scientific Investigation of the Qinghai-Tibet Plateau and the Strategic Pilot Technology Project of the Chinese Academy of Sciences.