Joan Maria Roure

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 precipitation, all of which are monthly and annual, using geographical information systems (GIS) techniques. The method can be seen as an alternative to classical interpolation techniques when spatial information is available. The geographical area used to develop and apply this model is Catalonia (32000 km 2 , northeast Spain). We have developed a multiple regression analysis between these meteorological variables as the dependent ones, and some geographical variables (altitude (ALT), latitude (LAT), continentality (CON), solar radiation (RAD) and a cloudiness factor (CLO)) as the independent ones. Data for the dependent variables were obtained from meteorological stations, and data for the independent variables were elaborated from a 180 m resolution digital elevation model (DEM). Multiple regression coefficients (bn) were used to build final maps, using digital layers for each independent variable, 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 0.70 and 0.89, while in the case of precipitation, it ranges between 0.60 and 0.91. Copyright

Characteristics of the aeropollen dynamics at several localities in Spain

Abstract In the Iberian Peninsula and Balearic Islands there are several bioclimatic regions which result in many different and fragmentary landscapes. Results obtained from monitoring 18 localities in Spain allow an outline of the aeropollen dynamics of some of these environments. The major pollen types are: I. trees: Pinus, Qvercus, Olea, Cupressaceae, 2. shrubs: Corylus, Pislacia and 3. herbs: Poaccae, Urticaceae, Chenopodiaceae-Amaranthaceae, Plantago and Asteraceae. In some locations Alnus, Artemisia, Buxus, Betula, Castanea, Eucalyptus, Populus, Ulmus, and Ephedra also have to be considered. Quantitatively, pollen from trees predominates over that from herbs and shrubs, although at some localities this trend varies. The first pollen grains found in the weekly atmospheric analyses are from trees (winter). In spring tree pollen grains share the atmosphere with herb pollen. For this reason it is usual to find peak values of pollen content in the atmosphere during this part of the year, while winter and...

Levels of Ambrosia pollen in the atmospheric spectra of Catalan aerobiological stations

AbstractAmbrosia pollen is known as an importantallergen in North America, and more recently in someEuropean countries. From 1989 to 1995, the Ambrosia pollen levels detected at the stationsmonitored by the Aerobiological Network of Catalonia(Xarxa Aerobiològica de Catalunya, XAC) wereinsignificant. In 1996, a considerable althoughtemporary increase in the concentration of this pollenwas detected in the atmosphere over Girona, Barcelona,Bellaterra, Manresa, and Tarragona. Most of the Ambrosia pollen collected in 1996 was concentrated ina single day. Its appearance on that day wasattributed to long range transportation, caused byunusual conditions of atmospheric circulation, fromthe Lyon region in France where the species isabundant. This is the only day where concentrations ofAmbrosia pollen that may be dangerous to humanhealth have been reached. Ambrosia coronopifolia is the most abundantspecies of the genus in Catalonia, and although rare,its expansion is favoured by the fact that it growsthrough rhizomes and sprouts easily. It is, therefore,important to monitor the growth of its population andthe release of its pollen in order to predict theappearance of pollen levels that may precipitateallergic symptoms.

Aerobiology of Vigo, North-Western Spain: atmospheric pollen spectrum and annual dynamics of the most important taxa, and their clinical importance for allergy

Vigo is a city located in the northwest of the Iberian Peninsula. Influenced by the Atlantic climate, it is surrounded by a Eurosiberian-type vegetation, modified by the introduction of forestry and ornamental species. Different ruderal vegetation types, resulting from human influence, grow in the area. The study of the pollen content of the air of Vigo started in 1989, with a Cour trap. Average results for the period 1989–1995 are presented in this paper, together with the lowest and highest values found. The representativeness of the mean values is analysed by calculating the coefficient of variation of the data series. Most pollen types in the atmosphere of Vigo are from tree species (54.2%); an important proportion comes from herb species (43.9%) and very few (1.8%) correspond to shrub species. A total of 73 different pollen types have been identified. The most abundant, listed in decreasing order of mean annual values for the period, are:Pinus (25.1%), Poaceae (21.1%), Urticaceae (14.6%),Quercus (8.5%),Castanea (3.7%),Betula (3.6%),Eucalyptus (3.4%),Plantago (3.2%),Alnus (2.1%), Cupressaceae (2.1%), Oleaceae (1.6%;Olea 1.3%),Platanus (1.3%),Rumex (1.3%), Chenopodiaceae/Amaranthaceae (1.0%), Ericaceae (0.8%), Asteraceae (0.6%;Artemisia 0.1% andTaraxacum type 0.2%) andMercurialis (0.5%). A pollen calendar showing the annual dynamics of all these pollen types is presented in this paper. A parallel study of the clinical importance of respiratory allergies in Vigo was also conducted. From a sample of 2750 patients, 87.2% suffered from rhinoconjunctivitis, 26.0% of these due to pollen, and 78.3% from asthma, 17.2% due to pollen. The pollen types responsible for these allergies, listed in decreasing order, are: Poaceae (78%),Parietaria (12%),Chenopodium (11%),Plantago (9%), Oak (4%),Artemisia (3%),Pinus (3%),Eucalyptus (3%),Olea (2%),Platanus (2%),Castanea (2%),Taraxacum (2%),Rumex (2%),Betula (1%),Cupressus (1%) andMercurialis (1%).