Search results for "rainfall"
showing 10 items of 233 documents
Intermediate-duration-rainfall intensity equations. Discussion by Vito Ferro
1997
Rainfall depth-duration relationships are presented.
USING HIGH RESOLUTION RAINGAUGE DATA FOR STORM TRACKING ANALYSIS IN THE URBAN AREA OF PALERMO, ITALY
2009
This paper presents a comparative analysis between rain-gauge storm tracking techniques in order to achieve a better knowledge of the rainfall dynamics over an urbanized area. The temporal and spatial distribution and kinematics of short term rainfall are recognized as one of the most important reasons in error production in rainfall-runoff on urban catchments. The uncertainty due to rainfall variability can greatly affect urban drainage modeling performance and reliability thus reducing the confidence of operators in their results. Modeling representations of urban catchments and drainage systems are commonly adopted for surface flooding forecasting and management and an adequate knowledge…
A physically-based and distributed tool for modeling the hydrological and mechanical processes of shallow landslides
2015
This work presents the capabilities of a model, i.e. the tRIBS-VEGGIE-Landslide, in two different versions, i.e. developed within a probabilistic framework and coupled with a root cohesion module. The probabilistic model treats geotechnical and soil retention curve parameters as random variables across the basin and estimates theoretical probability distributions of slope stability and the associated “factor of safety” commonly used to describe the occurrence of shallow landslides. The derived distributions are used to obtain the spatiotemporal dynamics of probability of failure, conditioned on soil moisture dynamics at each watershed location. The framework has been tested in the Luquillo …
DEM-resolution control on rainfall-triggered landslide modeling within a triangulated network-based model
2019
Catchment slope distribution significantly controls rainfall-triggered landslide modeling, in both direct and indirect ways. Slope directly determines the soil volume associated with instability. Indirectly, it affects the subsurface lateral redistribution of soil moisture across the basin, which in turn determines the water pore pressure conditions that impact slope stability. It is thus clear that the accuracy in reproducing slope distribution may be crucial in slope stability analysis. The resolution of the Digital Elevation Model (DEM) regulates the description of the topography. The correlation between raster resolution and landslide model outputs has been investigated in the literatur…
Theoretical advancements on a recently proposed method to measure rainfall energy
2022
Soil erosion induced by rainfall is mainly due to the rainfall impact besides the consequent surface runoff. Rainfall kinetic energy is the most used variable to represent its erosivity. The latter represents the weathering attitude to erode soil and is a fundamental variable of the erosion process. Consequently, precise measurements of rainfall erosivity have to perform to develop a reliable prediction model of the erosive phenomenon. Currently, impact energy can be reliably measured only by disdrometers. These instruments measure the Drop Size Distribution (DSD) which, joined with the raindrop falling velocity, allow to calculate, by integration, the impact kinetic energy. However, disdro…
Testing the Universal Soil Loss Equation-MB equation in plots in Central and South Italy
2019
Planning soil conservation strategies requires predictive techniques at event scale because a large percentage of soil loss over a long-time period is due to relatively few large storms. Considering runoff is expected to improve soil loss predictions and allows relation of the process-oriented approach with the empirical one, furthermore, the effects of detachment and transport on soil erosion processes can be distinguished by a runoff component. In this paper, the empirical model USLE-MB (USLE-M based), including a rainfall-runoff erosivity factor in which the event rainfall erosivity index EI30 of the Universal Soil Loss Equation (USLE) multiplies the runoff coefficient QR raised to an ex…
Revisiting rainfall to explore exam questions and performance on CS1
2015
The Rainfall problem comprises small tasks that have been used to investigate student performance in introductory programming. We conducted several kinds of analyses to inform our understandings of student performance in CS1 relating to this problem. We analyzed implementation approaches and program errors, as in related studies, and also explored the role of test writing vis-a-vis the most common student error. Finally, using correlation analyses and manual inspection of the exam answers, we studied how well the Rainfall problem served as an exam question. The students' implementation choices reflected their familiarity with particular loop constructs, while the single most common error co…
Towards Computer-based Exams in CS1
2017
Even though IDEs are often a central tool when learning to program in CS1, many teachers still lean on paper-based exams. In this study, we examine the “test mode effect” in CS1 exams using the Rainfall problem. The test mode was two-phased. Half of the participants started working on the problem with pen and paper, while the other half had access to an IDE. After submitting their solution, all students could rework their solution on an IDE. The experiment was repeated twice during subsequent course instances. The results were mixed. From the marking perspective, there was no statistically significant difference resulting from the mode. However, the students starting with the paper-based pa…
Variabilità delle serie storiche di temperatura e precipitazione in Sicilia
2008
A regional analysis of longer time series of temperature and rainfall, in Sicily, was performed. Trends and rainfall-temperature correlation was investigated, finding tipical droughty behaviour.
Spatial and temporal variability of rainfall over the Republic of Djibouti from 1946 to 2017.
2021
20 pages; International audience; For the first time, the spatial and temporal variability of rainfall in the Republic of Djibouti is investigated using data from 14 weather stations over the period 1946–2017. Due to limited data availability, high-resolution long-term satellite rainfall products (CHIRPS, PERSIANN-CDR, TAMSATv3, ARC2) and ERA5 reanalysis also contribute to document time–space rainfall variability at monthly, seasonal and annual scales. Principal component analysis identifies two spatially coherent regions of rainfall variability in the east (coastal zone) and the west (inland zone) of the country. Annual rainfall amounts are everywhere very low (60–300 mm), but with contras…