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The present research shows the results of possible effects of climate change on runoff and soil loss in a rainfed basin located in the Alt Penedès and Anoia region (NE Spain). Viticulture is an important economic activity in this region, and vines for the production of high-quality wines and 'cavas' are the main land use. Climate data for the period 2000-2012 and detailed soil and land use maps were used as input data for soil and water assessment tool to model the effects of climate change. The analysis compared simulated results for years with different climatic conditions during that period with predicted temperature and precipitation data for 2020, 2050 and 2080 based on data obtained from the Hadley Centre Coupled Model, version 3, A2 scenario and the trends observed in the area. The research confirmed the difficulty of predicting future soil loss in this region, which has very high inter-annual climate variability. Despite only small changes in precipitation, the model simulated a decrease in soil loss associated with a decrease in runoff, mainly driven by an increase in evapotranspiration. However, the trend in soil losses may vary when changes in precipitation balance the increase in evapotranspiration and when rainfall intensity increases. An increase in maximum rainfall intensity in spring and autumn (main rainy seasons) produced significant increases in soil loss: as high as 12 % for the 2020 scenario and 57 % for the 2050 scenario. [ABSTRACT FROM AUTHOR]

This paper presents the analysis of mean daily temperature and precipitation from 1950 to 2010 in an area with Mediterranean climate of NE Spain including some coastal areas near Barcelona and the Penedès and Camp de Tarragona Depressions located between the Coastal Mountain Range and the Mediterranean Sea. Their variability, with especial attention to the frequency of extreme events, was analysed by using 18 indexes: seven for temperature and 11 for precipitation were analysed for four meteorological observatories. A multivariate analysis was performed in order to analyse the temperature and precipitation trends. During the analysed period, an increase in mean annual maximum temperature was observed in all observatories ranging between 1.5 and 2.2°C associated with an increase in the number of days with high extreme temperatures. Minimum temperature only increased significantly in the coast observatories (about 1.4°C). By seasons, temperature trends were greater at Vilafranca del Penedès and Barcelona observatories and lower at Reus airport. Maximum spring temperature increased between 1.5 and 2.5°C, summer temperature increased between 1.6 and 2.5°C and autumn temperature increased by up to 2.2°C. Precipitation presented a high variability from year to year, without significant trends. The most significant results were related to the dry conditions observed in spring 2000s, the wet conditions recorded in summer 2000s and 1980s and the longer dry periods in autumn 2000s. The increase of temperatures determined the increase of evapotranspiration, and due to the higher irregular distribution, water deficits for crop development were recorded. An advance of phenological dates and a reduction of grape yield are associated to climate trends. [ABSTRACT FROM AUTHOR]