INVESTIGADORES
BIANCHI Lucas Osvaldo
congresos y reuniones científicas
Título:
A regional index of water balance inferred from satellite images of Laguna Llancanelo, Malargüe, Mendoza
Autor/es:
BIANCHI, LUCAS O.; ROJAS, FACUNDO; RIVERA, JUAN A.; VILLALBA, RICARDO
Lugar:
Malargüe
Reunión:
Encuentro; IAI meeting; 2014
Institución organizadora:
Interamerican Institute for global change research
Resumen:
The
Río Malargüe and other smaller streams feed Laguna Llancanelo, a
permanent shallow lagoon located close to the Andes, in Malargüe,
Mendoza. Being an endorheic basin, spatial variations in the size of
the Laguna Llancanelo can be used as a regional index of water
availability in the southern sector of the Mendoza province. In this
presentation, we update the development of a regional water stress
index derived from variations in the size of Laguna Llancanelo
determined from satellite images and the study of the relationships
between variations in lake size and remote (snowpack) and local
(rainfall) water inputs. Based on Landsat satellite images since the
mid-1980s, a monthly series of variations in size of this lagoon has
been developed for the last 30 years. This record, based on 289
satellite images has many missing data during the 1980s and 1990s, but
it is almost complete since the beginning of the 21th
century. The comparison between monthly variations in Llancanelo size
and in Río Malargüe streamflow at the Pincheiras gauge station,
suggest a close relationship between monthly snow-fed streamflow and lake size variations (r
= 0.6, n = 242). Local rainfall events may also play an important
role in lake fluctuations and therefore lake size variations were also
compared with regional precipitation records. We noted that some rapid
lake fluctuations are linked to intense precipitation events recorded
from the plains adjacent to the Andes. Regression analyses indicate
that the variability in Llancanelo size fluctuations are primary
modulated by snowpack melt and rainfall in the upper Cordillera (as
inferred from Rio Malargüe streamflows) and secondarily by local
rainfall events. The integration of winter (snowpack and rainfall) and
summer (rainfall) water sources from the Pacific and Atlantic Oceans
respectively, makes Laguna Llancanelo size variations a good index of
regional water balance east of the Andes.