Search results for "Ephemera"

A Maximizing Hydraulic Radius (MHR) method for defining cross-section limits in rills and ephemeral gullies

2021

Abstract In this paper, a new method for determining the cross-section limits in rills and ephemeral gullies is proposed. This method is based on the estimate of the actual depth ha of each cross-section, which is the particular depth distinguishing the channel from the hillslope areas. The analysis showed that the actual depth corresponds to a particular bank slope sta occurring for the maximum value of the hydraulic radius R. The method was applied using a volumetric approach for calculating the hydraulic radius as the ratio between the volume of the whole investigated channel and its boundary lateral surface. The value of the bank slope st was derived by the DEM of the whole channel late…

Morphological characteristics of ephemeral gullies in Sicily, south Italy

2011

Ephemeral gullies (EGs) are channels of different sizes refilled by tillage equipment normally used on farms. In this paper, the data-set collected from 1995 to 2007 in a wheat-cultivated area in Raddusa (Sicily, Italy), having a surface of almost 80 ha, were used to analyze the morphological characteristics of EGs. The measurements show an high temporal variability in EG characteristics. The EG measurements and the rill erosion measurements carried out in 15 plots located in the experimental “Sparacia” area (Sicily), demonstrated that a morphological similarity condition exists between rills and ephemeral gullies. The occurrence of step-pool structures in an EG occurring in the observation…

Testing the use of an image-based technique to measure gully erosion at Sparacia experimental area

2017

The first part of this investigation was aimed at testing the use of a three‐dimensional (3D) digital terrain model and a quasi‐tridimensional (2.5D) digital elevation model obtained by a large series of oblique images of eroded channels taken from consumer un‐calibrated and non‐metric cameras. For two closed earth channels having a different sinuosity, the ground measurement of some cross sections by a profilometer (P) was carried out and their real volume was also measured. The comparison among the three methods (3D, 2.5D, and P) pointed out that a limited underestimation of the total volume always occurs and that the 3D method is characterized by the minimum difference between measured a…

Similitudine morfologica tra i rill e gli ephemeral gully rilevati in Sicilia

2009

Rilievo del''erosione ephemeral gully in un piccolo bacino siciliano

2009

The Persian Glimpse

2020

The paper presents the results of a residential workshop dedicated to ephemeral architecture and urban renewal. Through theoretical lectures, planning and design exercises and a close relationship with the inhabitants inside the place to regenerate, the work-shop made it clear to the group of students coming from the Politecnico di Milano, the Academy of Fine Arts of Brescia and the University IUAV of Venice that “light” design elements can clearly transform the perception of a place by improving its liveability.

Una galassia seminata di stelle. Il festino di Santa Rosalia in una cronaca del 1693. Apparati effimeri e arti decorative

2018

Ripercorrendo le annotazioni del padre gesuita Ignazio de Vio sul Festino di Santa Rosalia del 1693 ci si sofferma sulle numerose personalità artistiche e sulle maestranze palermitane impegnate in quell'occasione ad abbellire il Cassaro con le loro creazioni, dagli argenti ai pregiati drappi, agli ori, alle gemme, agli stucchi, agli apparati effimeri. Going over the notes of the Jesuit Father Ignazio de Vio on the Festino di Santa Rosalia in 1693, one can linger over the numerous artistic personalities and workers from Palermo who were engaged on that occasion in embellishing the Cassaro with their creations, from silverware to precious drapes, gold, gems, stuccoes and ephemeral devices.

The Ephemera of Success: Strategy, Structure and Performance in the Forestry Industries

2006

The Role of Fire in Achieving the Sustainable Development Goals of the United Nations

2019

The Sustainable Development Goals (SDGs) of the United Nations do not mention Fire as a key factor in achieving an environmentally-friendly human society. This paper reviews the key aspects of the impact of fire that make it necessary to update the SDGs. Upon reviewing the scientific literature, it was found that fire has been part of the Earth System for the last 400 million years, and that it is part of biogeochemical cycles. From a geological perspective, fire shaped the current Earth System. Humans have used fire in the last million years as hunter-gatherers, and the last Pleistocene period evolved with the presence of fire. Since the Neolithic revolution, humankind spread the use of fi…

Formalized classification of ephemeral wetland vegetation (Isoëto-Nanojuncetea class) in Poland (Central Europe)

2021

Formalized classification of the class Isoëto-Nanojuncetea has not been performed in Poland. We used 69,562 relevés stored in Polish Vegetation Database. Based on the literature and expert knowledge we selected 63 diagnostic species for the Isoëto-Nanojuncetea class. Unequivocal classification was applied in this work according to Cocktail method. A set of formal definitions was established using a combination of logical operators of total cover of species in case of high-rank syntaxa while sociological species groups and cover of particular species were used for logical formulas describing class, alliances and associations. An Expert System was prepared and applied to classify the whole da…