Search results for " Rain"
showing 10 items of 221 documents
Investigating the Reliability of Stationary Design Rainfall in a Mediterranean Region under a Changing Climate
2023
Extreme rainfall events have been more frequent in recent decades, potentially as a climate change effect. This has been leading to a higher risk of the failure of existing hydraulic infrastructures, and to a higher awareness regarding the unreliability of design rainfall calculated with reference to historical data recorded in the last century. With this in mind, the present study questions the stationary assumption of the rainfall Depth–Duration–Frequency curves commonly used in Sicily, the biggest island of the Mediterranean Sea. Quantiles derived from the most up-to-date regional method, regarding Sicily, based on observations in the period 1928–2010, have been compared with those extra…
Changes in Climate and Land Use Over the Amazon Region: Current and Future Variability and Trends
2018
This paper shows recent progress in our understanding of climate variability and trends in the Amazon region, and how these interact with land use change. The review includes an overview of up-to-date information on climate and hydrological variability, and on warming trends in Amazonia, which reached 0.6-0.7 °C over the last 40 years, with 2016 as the warmest year since at least 1950 (0.9 °C +0.3°C). We focus on local and remote drivers of climate variability and change. We review the impacts of these drivers on the length of dry season, the role of the forest in climate and carbon cycles, the resilience of the forest, the risk of fires and biomass burning, and the potential “die back” of …
El futuro del derecho como lucha contra la idolatría tecnológica
2019
The main challenge that Law will have to face in the near future is the defense of human being against the uncontrolled power of technology in different spheres: ecology versus the becoming of a new geological age: the Anthropocene; the finances, versus speculation and taxes fraud; biolaw, versus the transhumanist challenge; the rights to privacy and no manipulation versus GAF( Google, Amazon, Facebook). El reto principal al que debera hacer frente el derecho en el futuro es la defensa del ser humano frente al poder incontrolado de la tecnologia en diferentes campos: la ecologia, frente a la aparicion de una nueva era geologica: el Antropoceno; las finanzas, frente a la especulacion y el fr…
The use of barley straw residues to avoid high erosion and runoff rates on persimmon plantations in Eastern Spain under low frequency-high magnitude …
2016
[EN] Soil and water losses due to agricultural mismanagement are high and non-sustainable in many orchards. An experiment was set up with rainfall simulation at 78 mm h(-1) over 1 hour on 20 paired plots of 2 m(2) (bare and straw covered) in new persimmon plantations in Eastern Spain. Effects of straw cover on the control of soil and water losses were assessed. An addition of 60% straw cover (75 gm(-2)) resulted in delayed ponding and runoff generation and consequently reduced water losses from 60% to 13% of total rainfall. The straw cover reduced raindrop impact and thus sediment detachment from 1014 to 47 g plot(-1) h(-1). The erosion rate was reduced from 5.1 to 0.2 Mg ha-(1) h(-1). The …
Extreme rainfall changes induced by future climate in Mediterranean area
2016
Extreme rainfall events have large impacts on society and are likely to continue to do so under predicted future climate change. Indeed, extreme precipitations show intensification in many regions of the world and this is of key importance to society as a result of the large impact of flooding. Thus, for planning and management decisions of the hydraulic infrastructures, accurate estimates of precipitation magnitudes at different durations are needed. Moreover, extreme precipitation events represent an increasing threat to society under global warming and are among the most serious challenges. In fact, future climate change is likely to lead to the change of extremes events that will become…
Uncertainty Analysis in the Evaluation of the DDF Curves Parameters in Climate Change Scenarios
2016
Abstract On the global scale, there is a robust observational evidence that, over the last decades, the frequency and intensity of extreme events significantly changed, even if regional and local studies have highlighted complex and non-uniform spatial patterns. Climate change can cause increased rainfall intensities which leads to an additional impact on drainage systems, due to the alteration of magnitude and frequency of peak flows over their service life. For this reason, the design criteria of urban drainage infrastructures need to be revised and updated, in order to take into account the possible variations of extreme rainfall. In particular, the Depth-Duration-Frequency (DDF) curves,…
High seedling recruitment of indigenous tree species in forest plantations in Kakamega Forest, western Kenya
2009
Tree plantations are often used to compensate for the destruction and conversion of natural forests in the tropics. An important question is whether these plantations allow for the regeneration of indigenous tree species and are expected to transform into more natural forests in the future. To evaluate the potential of differently managed forest types for seedling recruitment of indigenous tree species we studied structural characteristics as well as tree and seedling communities in stands of natural forest, different types of tree plantations and secondary forest in Kakamega Forest, western Kenya. Forest types differed considerably in structural characteristics and tree composition with st…
Seed dispersal by ants: are seed preferences influenced by foraging strategies or historical constraints?
2003
Summary The objective of this study was to quantify preferences of ants for seeds of different plant species and to test if these preferences were caused by foraging strategies or by historical constraints. We compared seed removal rates of ten different ant-dispersed plant species found in temperate forests, along forest edges and in grassland. We found significant differences in seed removal rates among the ten species. To test if these differences were caused by foraging strategies we examined the relationship between seed and elaiosome size and seed removal rate. We found that seeds with larger elaiosomes had significantly higher removal rates. To test the historical constraint hypothes…
A christmas gift: Signature of the 24th December 2018 eruption of Mt. Etna on the chemical composition of bulk deposition in eastern sicily
2020
The eruption of Mt. Etna which occurred on December 24th 2018 was characterized by strombolian activity and fire fountains, emitted by the New South-East Crater and along a fissure that propagated towards the SE. The influence of volcanic emissions on atmospheric deposition was clearly detectable at several kilometres from the source. Wet and dry (bulk) deposition samples were collected each month, through a network of eleven collectors, in the areas of Milazzo, and Priolo between June 2018 and June 2019. They were analysed for major ions and trace elements concentrations. The pH values range from 3.9 to 8.3, while the EC values range from 7 to 396 μS cm-1. An extensive neutralization of th…
Magmatic signature in acid rain at Masaya volcano, Nicaragua: Inferences on element volatility during lava lake degassing
2021
Abstract Major, minor and trace element concentrations of single rainfall events were investigated at Masaya volcano (Nicaragua) in order to determine the relative contributions of volcanogenic elements. Most of the samples were collected in the summit area of the volcano around the Santiago crater, and two samples, representative of the local background, were collected at a 4.3 km upwind site. Samples from the summit are very acidic with pH down to 2.14 and contain large amounts of volcanogenic elements that can be clearly distinguished from the local background. These elements are released into the atmosphere from the continuously degassing lava lake of the Santiago crater, Masaya volcano…