17 research outputs found
Lubrification hydrodynamique des paliers des machines tournantes
Available from INIST (FR), Document Supply Service, under shelf-number : 26165 A, issue : a.1997 n.118 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc
Dendrohydrology and water resources management in south-central Chile: lessons from the Río Imperial streamflow reconstruction
Streamflow in south-central Chile (SCC, ∼ 37–42° S) is vital
for agriculture, forestry production, hydroelectricity, and human
consumption. Recent drought episodes have generated hydrological deficits
with damaging effects on these activities. This region is projected to
undergo major reductions in water availability, concomitant with projected
increases in water demand. However, the lack of long-term records hampers the
development of accurate estimations of natural variability and trends. In
order to provide more information on long-term streamflow variability and
trends in SCC, here we report findings of an analysis of instrumental records
and a tree-ring reconstruction of the summer streamflow of the Río Imperial
( ∼ 37° 40′ S–38° 50′ S). This is the first
reconstruction in Chile targeted at this season. Results from the
instrumental streamflow record ( ∼ 1940 onwards) indicated that the
hydrological regime is fundamentally pluvial with a small snowmelt
contribution during spring, and evidenced a decreasing trend, both for the
summer and the full annual record. The reconstruction showed that streamflow
below the average characterized the post-1980 period, with more frequent, but
not more intense, drought episodes. We additionally found that the recent
positive phase of the Southern Annular Mode has significantly influenced
streamflow. These findings agree with previous studies, suggesting a robust
regional signal and a shift to a new hydrological scenario. In this paper, we
also discuss implications of these results for water managers and
stakeholders; we provide rationale and examples that support the need for the
incorporation of tree-ring reconstructions into water resources management