Lake water storage changes and their cause analysis in Mongolia.

Area of Science:

• Hydrology and Environmental Science
• Remote Sensing Applications
• Water Resource Management

Background:

• Mongolian lakes are vital water resources experiencing significant past decade variations.
• Monitoring long-term lake water storage (LWS) is challenging due to limited data.
• Understanding lake dynamics is crucial for effective water resource management in Mongolia.

Purpose of the Study:

• To estimate long-term changes in lake water storage (LWS) for 55 Mongolian lakes from 1991 to 2020.
• To identify the primary driving mechanisms behind observed LWS variations.
• To provide a scientific basis for water resource management and planning in Mongolia.

Main Methods:

• Utilized Advanced Land Observing Satellite Digital Elevation Model (ALOS DEM) and Joint Research Centre (JRC) datasets.
• Estimated LWS changes for 55 Mongolian lakes larger than 10 km² between 1991 and 2020.
• Employed a Generalized Linear Model to analyze the influence of precipitation, temperature, and irrigated area on LWS changes.

Main Results:

• Total LWS increased by 40.24 km³ from 1991-1997, particularly in northwestern Mongolia.
• LWS decreased by 32.44 km³ from 1998-2010 and further by 10.22 km³ from 2011-2020.
• Precipitation explained 45.13% of LWS change, followed by temperature (26.33%) and irrigated area (16.72%).

Conclusions:

• Mongolian lake water storage has shown significant variability over the past three decades.
• Precipitation is the dominant factor influencing LWS changes, followed by temperature and irrigation.
• Findings offer critical insights for sustainable water resource management and policy development in Mongolia.