Space–Time Simulations of Extreme Rainfall: Why and How?

2020 ◽  
pp. 53-71 ◽  
Author(s):  
Gwladys Toulemonde ◽  
Julie Carreau ◽  
Vincent Guinot
Keyword(s):  
Extreme Rainfall ◽  
Space Time

scholarly journals Characterizing the space–time structure of rainfall in the Sahel with a view to estimating IDAF curves

2014 ◽  
Vol 11 (7) ◽  
pp. 8409-8441 ◽  
Author(s):  
G. Panthou ◽  
T. Vischel ◽  
T. Lebel ◽  
G. Quantin ◽  
G. Molinié
Keyword(s):  
Extreme Rainfall ◽  
Rain Gauge ◽  
Space Time ◽  
Reduction Factor ◽  
Dynamic Scaling ◽  
Catchment Scale ◽  
Dynamical Scaling ◽  
Space And Time ◽  
Time Aggregation ◽  
Simple Scaling

Abstract. Intensity–duration–area–frequency (IDAF) curves are increasingly demanded for characterizing the severity of storms and for designing hydraulic structures. Their computation requires inferring areal rainfall distributions over the range of space–time scales that are the most relevant for hydrological studies at catchment scale. In this study, IDAF curves are computed for the first time in West Africa, based on the data provided by the AMMA-CATCH Niger network, composed of 30 recording rain gauges having operated since 1990 over a 16 000 km2 area in South West Niger. The IDAF curves are obtained by separately considering the time (IDF) and space (Areal Reduction Factor – ARF) components of the extreme rainfall distribution. Annual maximum intensities are extracted for resolutions between 1 and 24 h in time and from point (rain-gauge) to 2500 km2 in space. The IDF model used is based on the concept of scale invariance (simple scaling) which allows the normalization of the different temporal resolutions of maxima series to which a global GEV is fitted. This parsimonious framework allows using the concept of dynamic scaling to describe the ARF. The results show that coupling a simple scaling in space and time with a dynamical scaling relating space and time allows modeling satisfactorily the effect of space–time aggregation on the distribution of extreme rainfall.

scholarly journals Characterising the space–time structure of rainfall in the Sahel with a view to estimating IDAF curves

2014 ◽  
Vol 18 (12) ◽  
pp. 5093-5107 ◽  
Author(s):  
G. Panthou ◽  
T. Vischel ◽  
T. Lebel ◽  
G. Quantin ◽  
G. Molinié
Keyword(s):  
Extreme Rainfall ◽  
Rain Gauge ◽  
Space Time ◽  
Reduction Factor ◽  
Dynamic Scaling ◽  
Catchment Scale ◽  
Dynamical Scaling ◽  
Space And Time ◽  
Simple Scaling ◽  
Intensity Duration Frequency

Abstract. Intensity–duration–area–frequency (IDAF) curves are increasingly demanded for characterising the severity of storms and for designing hydraulic structures. Their computation requires inferring areal rainfall distributions over the range of space scales and timescales that are the most relevant for hydrological studies at catchment scale. In this study, IDAF curves are computed for the first time in West Africa, based on the data provided by the AMMA-CATCH Niger network, composed of 30 recording rain gauges having operated since 1990 over a 16 000 km2 area in south-western Niger. The IDAF curves are obtained by separately considering the time (intensity–duration–frequency, IDF) and space (areal reduction factor, ARF) components of the extreme rainfall distribution. Annual maximum intensities are extracted for resolutions between 1 and 24 h in time and from point (rain gauge) to 2500 km2 in space. The IDF model used is based on the concept of scale invariance (simple scaling) which allows the normalisation of the different temporal resolutions of maxima series to which a global generalised extreme value (GEV) is fitted. This parsimonious framework allows one to use the concept of dynamic scaling to describe the ARF. The results show that coupling a simple scaling in space and time with a dynamical scaling that relates to space and time allows one to satisfactorily model the effect of space–time aggregation on the distribution of extreme rainfall.

Space-time variability of extreme rainfall in the River Nile basin

2017 ◽  
Vol 37 (14) ◽  
pp. 4915-4924 ◽  
Author(s):  
Charles Onyutha ◽  
Patrick Willems
Keyword(s):  
Extreme Rainfall ◽  
Space Time ◽  
Time Variability ◽  
River Nile ◽  
Nile Basin

scholarly journals Multiscale Evaluation of Extreme Rainfall Event Predictions Using Severity Diagrams

2012 ◽  
Vol 27 (1) ◽  
pp. 174-188 ◽  
Author(s):  
Davide Ceresetti ◽  
Sandrine Anquetin ◽  
Gilles Molinié ◽  
Etienne Leblois ◽  
Jean-Dominique Creutin
Keyword(s):  
Time Scales ◽  
Rainfall Intensity ◽  
Mesoscale Model ◽  
Extreme Rainfall ◽  
Space Time ◽  
Extreme Rainfall Event ◽  
Maximum Rainfall ◽  
Rainfall Events ◽  
Rainfall Depth ◽  
Heavy Rainfall Events

Abstract Observations and simulations of rainfall events are usually compared by analyzing (i) the total rainfall depth produced by the event and (ii) the location of the rainfall maximum. A different approach is proposed here that compares the mesoscale simulated rainfall fields with the ground rainfall observations within the multiscale framework of maximum intensity diagrams and severity diagrams. While the first simply displays the maximum rainfall intensity of an event at a number of scales, the second gives the frequency of occurrence of the maximum rainfall intensities as a function of the spatial and temporal aggregation scales, highlighting the space–time scales of the event severity. For use in a region featuring complex relief, severity diagrams have been generalized to incorporate the regional behavior of heavy rainfall events. To assess simulation outputs from a meteorological mesoscale model, three major storms that have occurred in the last decade over a mountainous Mediterranean region of southern France are analyzed. The severity diagrams detect the critical space–time scales of the rainfall events for comparison with those predicted by the simulation. This validation approach is adapted to evaluate the ability of the mesoscale model to predict various types of storms with different regional climatologies.

scholarly journals A space-time rainfall generator for highly convective Mediterranean rainstorms

2003 ◽  
Vol 3 (1/2) ◽  
pp. 103-114 ◽  
Author(s):  
S. Salsón ◽  
R. Garcia-Bartual
Keyword(s):  
Point Processes ◽  
Rainfall Intensity ◽  
Practical Interest ◽  
Extreme Rainfall ◽  
Analytical Description ◽  
Space Time ◽  
Data Series ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Distributed Hydrological Models

Abstract. Distributed hydrological models require fine resolution rainfall inputs, enhancing the practical interest of space-time rainfall models, capable of generating through numerical simulation realistic space-time rainfall intensity fields. Among different mathematical approaches, those based on point processes and built upon a convenient analytical description of the raincell as the fundamental unit, have shown to be particularly suitable and well adapted when extreme rainfall events of convective nature are considered. Starting from previous formulations, some analytical refinements have been considered, allowing practical generation of space-time rainfall intensity fields for that type of rainstorm events. Special attention is placed on the analytical description of the spatial and temporal evolution of the rainfall intensities produced by the raincells. After deriving the necessary analytical results, the seven parameters of the model have been estimated by the method of moments, for each of the 30 selected rainfall events in the Jucar River Basin (ValenciaSpain) – period 1991 to 2000, using 5-min aggregated rainfall data series from an automatic raingauge network.

Space, Time and Einstein

2002 ◽  
Author(s):  
J. B. Kennedy
Keyword(s):  
Space Time

Spinors and Space-Time

1984 ◽  
Author(s):  
Roger Penrose ◽  
Wolfgang Rindler
Keyword(s):  
Space Time

Do Writing Directions Influence How People Map Space onto Time?

2018 ◽  
Vol 77 (4) ◽  
pp. 173-184
Author(s):  
Wenxing Yang ◽  
Ying Sun
Keyword(s):  
Mental Representations ◽  
Space Time ◽  
Horizontal Axis ◽  
Causal Role ◽  
Writing Systems ◽  
Temporal Cognition ◽  
Japanese Speakers ◽  
Psychological Experiments ◽  
Vertical Up

Abstract. The causal role of a unidirectional orthography in shaping speakers’ mental representations of time seems to be well established by many psychological experiments. However, the question of whether bidirectional writing systems in some languages can also produce such an impact on temporal cognition remains unresolved. To address this issue, the present study focused on Japanese and Taiwanese, both of which have a similar mix of texts written horizontally from left to right (HLR) and vertically from top to bottom (VTB). Two experiments were performed which recruited Japanese and Taiwanese speakers as participants. Experiment 1 used an explicit temporal arrangement design, and Experiment 2 measured implicit space-time associations in participants along the horizontal (left/right) and the vertical (up/down) axis. Converging evidence gathered from the two experiments demonstrate that neither Japanese speakers nor Taiwanese speakers aligned their vertical representations of time with the VTB writing orientation. Along the horizontal axis, only Japanese speakers encoded elapsing time into a left-to-right linear layout, which was commensurate with the HLR writing direction. Therefore, two distinct writing orientations of a language could not bring about two coexisting mental time lines. Possible theoretical implications underlying the findings are discussed.

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