Search results for "Trend analysis"
showing 10 items of 43 documents
Time series analysis of climate and vegetation variables in the Oreto watershed (Sicily, Italy)
2008
Assessing changes in rainfall erosivity in Sicily during the twentieth century
2007
Changes in rainfall erosivity are an expected consequence of climate change. Long-term series of the single storm erosion index, EI, may be analysed to detect trends in rainfall erosivity. An indirect approach has to be applied for estimating EI, given that long series of rainfall intensities are seldom available. In this paper, a method for estimating EI from the corresponding rainfall amount, he, was developed for Sicily. This method was then applied at 17 Sicilian locations, representative of different climatic zones of the region, to generate a long series (i.e. from 1916 to 1999 in most cases) of EI values. Linear and step (step located at 1970) trends in annual and seasonal erosivity …
Daily rainfall statistics in Sicily (1920-2000)
2012
Rainfall characteristics are crucial for vegetation patterns formation and evolution in Mediterranean ecosystems. Changes in rainfall frequency and intensity could cause vegetation water stress for some plant species and benefit, at the same time, other species, driving coexistence and competition dynamics. The changes in the precipitation characteristics are sometimes more important than the changes in the total amount of precipitation in determining the partitioning between green and blue water with several implications for both the vegetation communities health and water resource management. Decreasing rainfall is a clear signature of climate change in Mediterranean countries. Annual and…
In Itinere STRATEGIC ENVIRONMENTAL ASSESSMENT of an integrated provincial waste system
2009
In the paper, the practical problem of analysing in an integrated way the performance of provincial waste systems is approached, in the framework of the Strategic Environmental Assessment (SEA). In particular, the in itinere phase of SEA is analysed herein. After separating out a proper group of ambits, to which the waste system is supposed to determine relevant impacts, pertinent sets of single indicators are proposed. Through the adoption of such indicators the time trend of the system is investigated, and the suitability of each indicator is critically revised. The structure of the evaluation scheme, which is essentially based on the use of ambit issues and analytical indicators, calls …
Follow-up trends of parasite community alteration in a marine fish after the Prestige oil-spill: shifting baselines?
2008
This study evaluates the follow-up trends in the composition and structure of the parasite communities in the marine sparid Boops boops after the Prestige oil-spill. A total of 400 fish comprising 11 seasonal samples was analyzed from three impacted localities on the Atlantic coast of Spain. A large number of parasite species was recovered only after the spill thus suggesting a substantial alteration of the marine food webs. Post-spill communities exhibited higher richness and abundance due to the significant changes in the abundance of the common species, the latter indicating accelerated parasite transmission rates. Multivariate analyses at two nested scales detected a directional trend i…
EFFECTS OF DATA GAP ON THE CAPABILITY TO DETECT TREND IN HYDROCLIMATOLOGICAL TIME SERIES
2012
In the last decades the growing concerns about the existence of global climatic changes push many researchers to use different trend test in order to identify whether monotonic trends exist in hydroclimatological time series such as temperature, precipitation, and streamflow. Unfortunately, these time series often suffer from missing data values mainly due to malfunctioning of gauge for specific time periods. Starting from this premise, the main target of our work is to investigate the effect of data gap in a time series on the results provided by the most used trend test: the nonparametric Mann–Kendall statistical test. Firstly, different synthetic time series characterized by different si…
THE IMPACT OF ELECTION RESULTS ON THE MEMBER NUMBERS OF THE LARGE PARTIES IN BAVARIA AND GERMANY
2005
In this paper, we investigate the relations between the numbers of members of various parties and their results in the elections in Bavaria and in Germany. Deriving from the finding that there is a strong time-delayed correlation between these data-sets for the two largest parties in Bavaria, we show in a simulation based on the Sznajd model that such a correlation leads to very stable majorities, just as in Bavaria.
Expanding Research Capacity at United States Universities: a Study of Academic Research and Development Investment from 1990-2005
2012
Growing emphasis has been placed on universities to contribute to the innovation process and as a result academic research and development expenditures have increased in recent years. Nevertheless, little is known about the specific ways in which universities have expanded their research capacity.This paper examines how universities in the United States (US) have expanded research capacity as research funding has increased. Specifically, it identifies what type of research infrastructure, including various categories of human capital and research equipment, are most closely associated with increased academic research funding. Using data from 375 US universities spanning the period 1990‐2005…
Recent climate change in Japan ? spatial and temporal characteristics of trends of temperature
2008
Abstract. In this paper temperature series of Japan were statistically analysed in order to answer the question whether recent climate change can be proved for Japan; the results were compared and discussed with the global trends. The observations in Japan started for some stations in the 1870s, 59 stations are available since 1901, 136 stations since 1959. Modern statistical methods were applied, such as: Gaussian binominal low-pass filter (30 yr), trend analysis (linear regression model) including the trend-to-noise-ratio as measure of significance and the non-parametric, non-linear trend test according to MANN (MANN's Q). According to the results of the analyses, climate change in Japan …
Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018…
2018
Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean dia…