Frost risk mapping derived from satellite and surface data over the Bolivian Altiplano

Summer frosts occur frequently on the Bolivian Altiplano (4000 m) and cause severe damage to potato and quinua crops. A regional statistical study of frost risks must combine meteorological data with satellite data. In this w ork, a new method is developed to use NOAA satellite temperatures together with local minimum air temperature data. This method enables point meteorol ogical data (with important historical records) to be combined with satelli te data (spatially extended but with poor temporal coverage). The method in volves several stages including a classification of the Altiplano based on the meteorological stations, a calculation of minimum temperatures over the whole Altiplano for several years of data, and finally the computation of minimum temperatures and frost risk percentage maps. The precision obtained in the resulting synthesis images is 0.8 degrees C for the average minimum temperatures and 9% for frost risk maps. (C) 1999 Elsevier Science B.V. Al l rights reserved.