Climate-Driven Changes in Lake Areas for the Last Half Century in the Valley of Lakes, Govi Region, Southern Mongolia

Abstract

This study presents the changes in lake areas in the Valley of Lakes, the Govi region, southern Mongolia. The recent changes in lake areas show decreases depending on vulnerability of lake basins and response of Govi landscape to the present climatic warming. During the recent 44-45 years (from 1970 to 2014 or 2015), modern lakes have encountered the present rapid increase in temperature, water evaporation and drying up that induced the reduction in lake areas in the Valley of Lakes. The finding of the reduction in lake areas is consistent with the trends on increasing in temperature since 1995 and fluctuating precipitation since 1975. Investigations with detailed chronology of lake sediment are needed from the lakes to review a more complete evolution of lake basins during the Late Quaternary paleoclimatic history in Mongolia and Central Asia.

Late Holocene Sedimentation Dynamics in the Lake Ulaan Basin, Southern Mongolia: A History of a Playa Lake 

“…1b). Because this lake basin is at the lowest elevation in the Valley of Lakes (Orkhonselenge et al 2018a), thick alluvial and lacustrine deposits were accumulated in the past (Tsegmid 1969). Lake Ulaan is hypothesized as a deposition center for the whole lake basin system in the Valley of Lakes during the Quaternary (Tserensodnom 2000).…”

“…Although Lake Ulaan has experienced uctuations of shrinking and/or lling depending on the annual precipitation and temperature (Orkhonselenge et al 2018a) since the 1950s, the lake has nally shifted to become a playa (Fig. 9c).…”

“…9c). This was due to the strong westerly wind effects exceeding 20-25 m/s (Amarjargal 2016) and extreme over usage of groundwater by mining operation in the basin in addition to the rapidly rising air temperature (Orkhonselenge et al 2018a). The playa condition (Fig.…”

“…Severe droughts in the eastern Govi region, observed since the late 1990s, have intensi ed the groundwater level and lake area (Kang et al 2015). Climate data observed at meteorological stations in the Valley of Lakes during 1975-2015 show trends in temperature rise since 1995 and precipitation uctuations since 1975 (Orkhonselenge et al 2018a). Rivers, feeding lakes in the Govi region, decrease in discharges in all seasons at the present time (Davaa 2015).…”

“…In recent years, Lake Ulaan has attracted numerous detailed studies in geomorphology, sedimentology, hydrology, and paleogeography. For instance, Lake Ulaan's water level dropped by 1-2 m since 1980 (Batnasan 1998), and the lake faced the challenge of the continuous decrease in its area due to the rising temperature over the last half-century (Orkhonselenge et al 2018a). However, there has been little research about how sedimentation records past climates in the Lake Ulaan basin and its evolutionary history during the geological period.…”