Estimate of the (R)USLE rainfall erosivity factor from monthly precipitation data in mainland Spain

The need for continuous recording rain gauges makes it difficult to determine the rainfall erosivity factor (R-factor) of the (R)USLE model in areas without good temporal data coverage. In mainland Spain, the Nature Conservation Institute (ICONA) determined the R-factor at few selected pluviographs, so simple estimates of the R-factor are definitely of great interest. The objectives of this study were: (1) to identify a readily available estimate of the R-factor for mainland Spain; (2) to discuss the applicability of a single (global) estimate based on analysis of regional results; (3) to evaluate the effect of record length on estimate precision and accuracy; and (4) to validate an available regression model developed by ICONA. Four estimators based on monthly precipitation were computed at 74 rainfall stations throughout mainland Spain. The regression analysis conducted at a global level clearly showed that modified Fournier index (MFI) ranked first among all assessed indexes. Applicability of this preliminary global model across mainland Spain was evaluated by analyzing regression results obtained at a regional level. It was found that three contiguous regions of eastern Spain (Catalonia, Valencian Community and Murcia) could have a different rainfall erosivity pattern, so a new regression analysis was conducted by dividing mainland Spain into two areas: Eastern Spain and plateau-lowland area. A comparative analysis concluded that the bi-areal regression model based on MFI for a 10-year record length provided a simple, precise and accurate estimate of the R-factor in mainland Spain. Finally, validation of the regression model proposed by ICONA showed that R-ICONA index overpredicted the R-factor by approximately 19%.

Visibilidad y percepción en la construcción de un paisaje Prehistórico. El caso de Calviá (Mallorca, Islas Baleares)

El presente trabajo se centra en el estudio del papel que juega el control visual del espacio en las prácticas sociales de las comunidades prehistóricas. Este trabajo se articula a partir de un estudio de caso, el término municipal de Calviá, situado en el sureste de la isla de Mallorca, para analizar las diferentes formas de monumentalidad arquitectónica y cómo estas se constituyen cómo un punto de referencia social dentro del paisaje. Partiendo de una amplia horquilla temporal, que abarcaría el Bronce Naviforme (1550-850 AC), el período Talayótico (850-550 AC) y el Postalayótico (550-123 AC), se propone analizar los cambios y pervivencias en la construcción del paisaje, a través de estrategias de visibilidad, percepción y movimiento alrededor de los monumentos arquitectónicos. A través de la perspectiva de la Arqueología del Paisaje y mediante el uso de Sistemas de Información Geográfica (SIG) se propone un análisis de tendencias a largo plazo en la configuración social de un paisaje.