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EVALUATION AND MONITORING OF 
SNOWCOVER WATER RESOURCES IN CARPATHIAN BASINS USING 
GEOGRAPHIC INFORMATION AND SATELLITE DATA 
Gheorghe Stancalie, Simona Catana, Anisoara Iordache 
National Institute of Meteorology and Hydrology (NIMH), 97, Soseaua Bucuresti-Ploiesti, 
Sector 1, 013686 Bucharest, Romania - (gheorghe.stancalie, simona.catana, anisoara.iordache)@meteo.inmh.ro 
KEY WORDS: Snow Ice, Satellite, Monitoring, Integration, GIS, DEM 
ABSTRACT: 
The paper describes the working methods developed in the Remote Sensing Lab of the National Institute of Meteorology and 
Hydrology in Bucharest and the obtained results for: basin snowcover areal extent and snowline elevation determination, new 
snowfalls identification, melting zones discrimination, snowpack water volume determination, snowcover depletion curves, etc. 
The method for evaluation the water resources stored in the snowpack is based on the use of data from three investigation levels: 
satellite, air and ground. This approach is required by: 
- the complex physiographical peculiarities of the Carpathian watershed; 
- the necessity of determining both the extent of the snowcover and its condition; 
- the instability in time, during the winter-spring season, of the maximum stored amount, and the snowmelt process beginning which 
requires a continuous surveillance of the snowcover; 
- the need to correlate remotely sensed data with the ground truth. 
A complex related geo-referenced database, consisting of high and medium resolution satellite data (NOAA-AVHRR, TERRA- 
MODIS, LANDSAT-TM, SPOT-XS), terrain information derived from Digital Elevation Models (DEM) and other exogenous data 
(maps and ground measurements) was designed and implemented on PC-based computing systems. The GIS developed for the 
snowcover water resources management includes information referring to the topography, land vegetation cover, land use, soil type, 
, hydro-meteorological parameters, that could be used as separate layers or interconnected in order to extract the necessary 
information for a correct and accurate estimation of the snowpack conditions and snowcover water resources during the winter- 
  
spring period. 
1. INTRODUCTION 
The surveillance and the management of the water resources in 
Romania represent an issue of national importance considering 
the fact that the natural potential of the water courses is rather 
reduced, altered by water consuming users and by those which 
redistribute the flow in time. Although the number of the 
watercourses is considerable, Romania is situated among the 
European countries with relatively poor water resources; the 
multi-annual mean runoff for the Romanian territory reaches 
the limit of the hydrological drought, over extensive areas in the 
east and southeast. 
Water resources management requires a permanent surveillance 
in space and time of the snow cover, one important natural 
water resource. This activity requires a great number of 
Observations points and stations of measurement and 
processing. 
The remote sensing technologies have known an unprecedented 
development in the latest years; there are many operational 
Systems with sensitive sensors in many areas of the 
electromagnetic spectrum, from visible to microwave, with 
spatial and temporal resolutions extremely notable. Now, the 
remote sensing represents a viable alternative, being able to 
supply observations and global measurement at the level of a 
hydrological basin or for larger areas. The remote sensing 
techniques offer important advantages such as: 
- areal measurements; 
- gathering and unitary data storage; 
263 
- good spatial and temporal resolution; 
- data available in numerical format; 
- availability of data in less accessible areas; 
- the acquisition systems do not interfere with the process and 
observed phenomena. 
Among the major difficulties connected with the obtaining and 
use of the remote sensing data, the atmospheric conditions are 
to be noticed for the optical sensors and those linked with the 
calibration of the information by means of field data in 
hydrological terms. 
Remote sensing data play a rapidly increasing role in the field 
of snow hydrology. Although only very few remotely sensed 
data can be directly applied in this field, such information is of 
great value since many hydrological relevant data can be 
derived from remote sensing information. One of great 
advantages of remote sensing data in hydrology consists in the 
areal information instead of the usual point data. This 
information is usually digitized in form of picture elements, the 
scale of which depends on the sensors, which are used. Large 
quantities of raster data are collected with the aid of various 
platforms and sensors. These large data amounts require well 
organized data banks as well as user friendly data processing 
hardware and software. 
It was noticed that remote sensing data would be particularly 
valuable for regions with complex terrain, when the snow 
parameters, such as snow-water equivalent, may vary 
significantly over small areas. Such data need to be compared