TITLE:
Thermokarst Lake Changes in the Southern Fringe of Siberian Permafrost Region in Mongolia Using Corona, Landsat, and ALOS Satellite Imagery from 1962 to 2007
AUTHORS:
Adiya Saruulzaya, Mamoru Ishikawa, Yamkhin Jambaljav
KEYWORDS:
Thermokarst Lake, Siberian Permafrost Region, Mongolia, Corona, Landsat, ALOS
JOURNAL NAME:
Advances in Remote Sensing,
Vol.5 No.4,
November
1,
2016
ABSTRACT: This study presents thermokarst lake changes at seven different sites in the continuous
and isolated permafrost zones in Mongolia. Lakes larger than 0.1 ha were analyzed
using Corona KH-4, KH-4A and KH-4B (1962-1968), Landsat ETM + (1999-2001), and ALOS/AVNIR-2 (2006-2007) satellite imagery. Between 1962 and 2007,
the total number and area of lakes increased by +21% (347 to 420), and +7% (3680
ha to 3936 ha) in the continuous permafrost zone, respectively. These changes correspond
to the appearance of 85 new lakes (166 ha) during the last 45 years. In contrast,
lakes in the isolated permafrost zone have decreased by –42% (118 to 68) in
number and –12% (422 ha to 371 ha) in area from 1962 to 2007. The changes in lake
area and number are likely attributed to shifts in climate regimes and local permafrost
conditions. Since 1962, the mean annual air temperature and potential evapotranspiration
have increased significantly in the northern continuous permafrost
zone compared to the southern isolated permafrost zone. Due to ongoing atmospheric
warming without any significant trend in annual precipitation, patches of
ice-rich subsurface have thawed, and the number and area of lakes have accordingly
developed in the continuous permafrost zone. Shrinking of thermokarst lakes in the
isolated permafrost zone may be due to disappearing permafrost, deepening of the
active layer, and increased water loss through surface evaporation and subsurface
drainage.