What leads Musters and Colhué Huapí lake area fluctuations (1998-2014): climate and discharge data analysis

FACUNDO SCORDO; GERARDO M. E. PERILLO; M. CINTIA PICCOLO

Chuncheon

Workshop; GLEON 17 Chuncheon, South Korea; 2015

Global Lake Ecological Observatory Network - Korean Society of Limnology - Kangwon Nation University - National Institute of Ecology - National Institute of Environmental Reserch - Korean Environment Corporation - National Science Foundation

Satellite information, climate and discharge data are important tools to understand the dynamics of water bodies. The evolution of Muster and Colhué Huapí lakes in the period 1998- 2014 was studied. The former is a deep (depth 35 m) and narrow lake (width 12 km; length 40 km). It has a tectonic origin with high elevations (900 m) on the Western, Northern and Central East coast. On the contrary, Colhué Huapí is a shallow (depth 2 m) large lake (width 23 km; length 50 km). It has a tectonic origin then deepened by eolic and fluvial activity. Except for the Northern Coast (500 m) most of the lake presents a smooth elevation on its shores.The lakes are separated by a ridge that reaches 600 m (oriented NS) and the Senguer River interconnects them. The aim of this work is to study the fluctuations in lake area related to climate (rainfall, temperature and wind intensity) and discharge within the period 1998-2014. The relation of those variations with ENSO events is also analyzed. Multiple regressions were estimated between lake area, as a dependent variable, and discharge and climate data, as independent variables. The results showed that in the study period, lakes changed from dry to wet condition every 7 years. The changes in the area are more evident in the Colhué Huapí Lake because it is significantly shallower. In 2001 Coluhé Huapí lake area was 105 km2 and increased until 2007, when it reached its largest extension (797 km2) to decrease to 303 km2 in 2014. The lake area variations could be explained by the joint effect of mean discharge, wind intensity and accumulate precipitation in two years preceding satellite image acquisition and mean temperature in one year preceding satellite image acquisition (CH = 77% and MU = 82%). Differences in the variables explaining lakes area variations are mainly due to the physical characteristics of both lakes. ENSO events are of importance in the Senguer river discharge affecting the Musters and Colhué Huapí lakes.