Hydrological modelling study with digital image processing of multi-sensor satellite data over a small high mountainous catchment

The integration of visible and infrared satellite remote sensing information is made with ground meteorological and hydrological data to study the application of a semi-distributed temperature index model over a small high mountainous catchment in the Italian Alps. Nine sets of digital Landsat MSS and TM images covering a hydrological year were processed. Digital elevation model, slope, aspect and shaded relief maps coinciding with the satellite passes were generated using locally developed software known as Territorial Image Synthesis System (TISS). The areal extent of snow cover over the catchment for each scene has been estimated using parallele-piped, nearest neighbour and maximum likelihood methodologies of supervised classification. Daily snow depletion curves were developed and incorporated as input to the Snowmelt Runoff Model (SRM), along with pre-determined catchment morphological parameters. The model performance evaluation has indicated excellent results when compared to those obtained on other catchments of similar areal extent in different parts of the world. K e y words A lps (I ta ly) ; digi ta l e leva t ion m o d e l ; i m a g e p roce s s ing ; s n o w cover ; s n o w m e l t runoff m o d e l ; superv i sed c lass i f icat ion; Terr i tor ia l I m a g e Syn thes i s S y s t e m ( T I S S ) ; wa te r r e sources m a n a g e m e n t