Minora U.,Comitato EvK2CNR |
Minora U.,University of Milan |
Minora U.,Polytechnic of Milan |
Godone D.,Comitato EvK2CNR |
And 11 more authors.
Geografia Fisica e Dinamica Quaternaria | Year: 2015
Snowmelt contributes largely to water budget of several Chilean mountain watersheds. To describe snow covered area (SCA) variability within 18 watersheds in Central Chile during 2008-2011 we used MODIS data (i.e. MOD10A2-V5 maximum snow cover extent in eight-day periods). The study area was divided into three different zones (Northern, Central, and Southern), due to its large extent (205,000 km2), and according to former studies performed by the Direccíon General de Aguas (DGA) of the Chilean Government covering the time window 2000-2007. After georeferencing our data to the WGS84 Datum (UTM Projection, zone 19S), the scenes were cropped to fit the study area. We selected and set a threshold for cloud coverage (<30%) in order to discard the images with too cloud cover, so losing only 2% of the sample. Hypsographic and aspect analyses were performed using the SRTM3 elevation model. We found largest values of SCA during 2008-2011 in the Central Zone, while the topographic and climatic features (i.e. lower altitudes in the South, and a drier climate in the North) limit snow deposition elsewhere. Similarly, snow line is higher in the Northern zone (due to the presence of the plateau), and lower moving southwards. In the North the minimum SCA is reached sooner than elsewhere, lasting for a longer period (November to March). West side showed the maximum of SCA in all zones throughout the study period. The present work extends in time the dataset of SCA in the Central Chile, adding information for statistic assessment, and trend analysis of snow cover in this area.
Senese A.,University of Milan |
Diolaiuti G.,University of Milan |
Verza G.P.,Comitato EvK2CNR |
Smiraglia C.,University of Milan
Geografia Fisica e Dinamica Quaternaria | Year: 2012
This paper reports the surface energy budget and the melt amount evaluated at one location at the Forni Glacier (Italian Alps, Lombardy) during the years 2009 and 2010. The analysis was supported by high resolution meteorology and energy data collected by an Automatic Weather Station (named AWS1 Forni) which has been running at the glacier surface (2669 m, ellipsoidal elevation) since 26 September 2005. The AWS is also equipped with a sonic ranger to measure snow depth and its variability. It resulted that in the years 2009 and 2010 the glacier melt at about 2700 m of altitude was equal to -11.32 m w.e.; these results were confirmed by comparisons with field ablation data collected nearby the AWS during the summer season 2009 and 2010.