A methodological approach of climatological modelling of air temperature and precipitation through GIS techniques

This study proposes an empirical methodology for modelling and mapping the air temperature (mean maximum, mean and mean minimum) and total precipitati on, all of which are monthly and annual, using geographical information sys tems (GIS) techniques. The method can be seen as an alternative to classica l interpolation techniques when spatial information is available. The geogr aphical area used to develop and apply this model is Catalonia (32000 km(2) , northeast Spain). We have developed a multiple regression analysis betwee n these meteorological variables as the dependent ones, and some geographic al variables (altitude (ALT), latitude (LAT), continentality (CON), solar r adiation (RAD) and a cloudiness factor (CLO)) as the independent ones. Data for the dependent variables were obtained from meteorological stations, an d data for the independent variables were elaborated from a 180 m resolutio n digital elevation model (DEM). Multiple regression coefficients (b(n)) we re used to build final maps, using digital layers for each independent vari able, and applying basic GIS techniques. The results are very satisfactory in the case of mean air temperature and mean minimum air temperature, with coefficients of determination (R-2) between 0.79 and 0.97, depending on the month; in the case of mean maximum air temperature, R-2 ranges between 0.7 0 and 0.89, while in the case of precipitation, it ranges between 0.60 and 0.91. Copyright (C) 2000 Royal Meteorological Society.