Review status: this preprint is currently under review for the journal HESS.
Changes in glacial lakes in the Poiqu River Basin in the central Himalayas
Pengcheng Su1,2,Jingjing Liu1,2,Yong Li1,2,Wei Liu1,2,Yang Wang1,and Chun Ma1,2Pengcheng Su et al.Pengcheng Su1,2,Jingjing Liu1,2,Yong Li1,2,Wei Liu1,2,Yang Wang1,and Chun Ma1,2
1Key Laboratory of Mountain Hazards and Surface Process/Institute of Mountain Hazards and Environment, Chinese Academy of Science, Chengdu, 610041, China
2University of Chinese Academy of Sciences, Beijing, 100049, China
1Key Laboratory of Mountain Hazards and Surface Process/Institute of Mountain Hazards and Environment, Chinese Academy of Science, Chengdu, 610041, China
2University of Chinese Academy of Sciences, Beijing, 100049, China
Received: 16 Jan 2020 – Accepted for review: 17 Feb 2020 – Discussion started: 03 Mar 2020
Abstract. The Poiqu River Basin contains 162.2 km2 of ice and 19.9 km2 of glacial lakes. The remote sensing data over the last 40 years have been used to identify 147 glacial lakes in the basin and clearly revealed the retreat of glaciers and the growth of glacial lakes at accelerating rates, in parallel to warming climate in the Himalayas. Based on remote sensing images and digital elevation model (DEM) analysis, the area and water changes in glaciers and glacial lakes are analyzed in detail, and a water balance equation (WBE) is proposed to account for the mechanism of lake growth. The WBE includes water supplies from rainfall runoff, ice and snow ablation, glacial retreat, and water losses due to infiltration and evaporation. As each water contribution item specifically depends on local weather and morphology, the WBE provides a direct link between glacier and glacial lake changes and climate changes under local conditions. Operation of the WBE for five major glacial lakes in the Poiqu River Basin has revealed that water from glaciers and snow cover dominates the growth of lakes. Lakes are found to vary in different ways even with similar backgrounds, depending strongly on local weather and geomorphology conditions. The WBE is not only applicable for predicting future changes in glacial lakes under climate warming conditions but is also useful for assessing water resources from rivers in the central Himalayas.
Glaciers and glacial lakes are sensitive to temperature, while other studies give an overall view of glacier/glacial lake changes with climate change at large scale. For this we make a close scrutiny to glacial lakes in the Poiqu River with the highest concentration of glacial lake in central Himalayas, which provides a complete scenario of how glaciers and glacial lakes change in response to local weather conditions and also a framework for the water balance in rivers from glacierized sources.
Glaciers and glacial lakes are sensitive to temperature, while other studies give an overall...