Impact of spatial resolution and interpolation schemes of precipitation data on hydrological modeling

Author(s):  
Clara Hohmann ◽  
Sungmin Oh ◽  
Gottfried Kirchengast ◽  
Ulrich Foelsche ◽  
Wolfgang Rieger

<p>Hydrological modelling depends strongly on precipitation input. Especially, to simulate very localized heavy precipitation events, models require precipitation information with a high spatial and temporal resolution. In order to study the influence of precipitation station densities and interpolation schemes on hydrological model performance, we use gauge data from the highly dense station network WegnerNet (www.wegenernet.org). The WegenerNet is located in the southeastern Alpine forelands of Austria. It measures precipitation and other meteorological variables at a 5-min time sampling with about 150 climate stations in an area of about 22 km x 16 km (i.e ~ one station per 2 km²). We complement these data by the operational networks of the Austrian weather and hydrographic services (ZAMG and AHYD), leading to a total of 158 stations.</p><p>This highly dense station network permits us to analyze the precipitation data uncertainty for specific short and long duration events over the lower Styrian Raab catchment (about 500 km²) and its sub-catchments (about 10 to 50 km²). For modeling, we employ the process-based model WaSiM (www.wasim.ch) with a 100 m x 100 m spatial and a 30 minutes temporal resolution. We calibrated the model with all 158 precipitation stations and inverse distance weighting (IDW) interpolation scheme; this simulation is used as our reference run (Ref-158). We performed further simulations with only stations from ZAMG, the 5-Stations case, also include the stations from AHYD (adding another 3 stations), the 8-Stations case, and step by step including stations from the WegenerNet, the 16-Stations, 32-Stations and 64-Stations cases. For each simulation, we compared three interpolation schemes: two IDW setups and Thiessen polygons. Our study focuses on short duration, local extremes (convective events in 2009, 2010, 2011), but for comparison also includes long duration frontal extreme events.</p><p>Our results suggest that for the runoff simulation with dense precipitation stations (Ref-158) the effect of the interpolation scheme is negligible. By contrast, modeling with low-resolution precipitation data obtained from less than 10 stations, the interpolation scheme leads to deviations of over 20% in terms of peak flow. These deviations are especially pronounced for the short duration events. For the total Styrian Raab catchment, the 32-Stations case is as good as the Ref-158 case, independent of the interpolation scheme (mostly smaller than 10% deviation). For the long duration events and the IDW interpolation scheme even, the 5-Stations case is sufficient. For the smaller catchments, the peak flow is much more event-dependent. More stations do not necessarily lead to less deviation to the reference and no clear under- or over-estimation is visible.</p>

2020 ◽  
Author(s):  
Clara Hohmann ◽  
Gottfried Kirchengast ◽  
Sungmin O ◽  
Wolfgang Rieger ◽  
Ulrich Foelsche

Abstract. Precipitation is a key input to hydrological models. While rain gauges provide the most direct precipitation measurements, their accuracy in capturing rain patterns highly depends on the spatial variability of rainfall events and the gauge network density. In this study, we employ a high-resolution meteorological station network (mean station distance of 1.4 km), the WegenerNet in southeastern Austria, to investigate the impact of station density and interpolation schemes on runoff simulations. We first simulate runoff during heavy precipitation (three short-duration and three long-duration events) using a physically based hydrological model with precipitation input obtained from a full network of 158 stations. The same simulations are then repeated with precipitation inputs from subnetworks of 5, 8, 16, 32, and 64 stations, using three different interpolation schemes – Inverse Distance Weighting with a weighting power of 2 and of 3, respectively, and Thiessen polygon interpolation. We find that the performance of runoff simulations is greatly influenced by the spatial variability of precipitation input, especially for short-duration rainfall events and in small catchments. For long-duration events, reliable runoff simulations in the study area can be obtained with a subnetwork of 16 or more well-distributed gauges (mean station distance of about 6 km). We find a clear effect of interpolation schemes on runoff modeling as well, but only for low-density gauge networks. The sensitivity to the precipitation input is smaller for long-duration heavy precipitation events and bigger catchments. As a next step we suggest to study an ensemble of precipitation datasets in combination with runoff modeling to be able to decompose the effects of precipitation measurement uncertainties and its spatial variability.


2021 ◽  
Vol 9 ◽  
Author(s):  
Daiqiang Liao ◽  
Qiang Zhang ◽  
Ying Wang ◽  
Haonan Zhu ◽  
Jia Sun

Based on minute-by-minute precipitation data from 1961 to 2016 obtained from the National Basic Weather Station of Shapingba, Chongqing, China, the Chicago rainstorm method, the Pilgrim & Cordery (P&C) method, the Common-frequency method and the natural rainstorm moving regularity (NRMR) method were used to design short-duration (1–3 h) and long-duration (24 h) rainstorm hyetographs. Then, a standardization method for test samples was designed to ensure that each test sample was standardized and underwent an actual precipitation process. The designed rainstorm hyetographs and test samples were compared and analyzed, and the results show that the hyetographs for the 1, 3, and 24-h durations obtained with the NRMR method best represented the actual corresponding precipitation processes. The hyetograph for the 2-h duration obtained with the Chicago rainstorm method was best for the actual 2-h precipitation process. The design results of the Common-frequency method were generally good, but not outstanding. Finally, the P&C method showed a relatively poor performance for each duration.


Author(s):  
Omar J Guerra ◽  
Joshua Eichman ◽  
Paul Denholm

Achieving 100% carbon-free or renewable power systems can be facilitated by the deployment of energy storage technologies at all timescales, including short-duration, long-duration, and seasonal scales; however, most current literature...


1989 ◽  
Vol 62 (6) ◽  
pp. 1225-1236 ◽  
Author(s):  
S. M. Gurahian ◽  
S. H. Chandler ◽  
L. J. Goldberg

1. The effects of repetitive stimulation of the nucleus pontis caudalis and nucleus gigantocellularis (PnC-Gi) of the reticular formation on jaw opener and closer motoneurons were examined. The PnC-Gi was stimulated at 75 Hz at current intensities less than 90 microA. 2. Rhythmically occurring, long-duration, depolarizing membrane potentials in jaw opener motoneurons [excitatory masticatory drive potential (E-MDP)] and long-duration hyperpolarizing membrane potentials [inhibitory masticatory drive potentials (I-MDP)] in jaw closer motoneurons were evoked by 40-Hz repetitive masticatory cortex stimulation. These potentials were completely suppressed by PnC-Gi stimulation. PnC-Gi stimulation also suppressed the short-duration, stimulus-locked depolarizations [excitatory postsynaptic potentials (EPSPs)] in jaw opener motoneurons and short-duration, stimulus-locked hyperpolarizations [inhibitory postsynaptic potentials (IPSPs)] in jaw closer motoneurons, evoked by the same repetitive cortical stimulation. 3. Short pulse train (3 pulses; 500 Hz) stimulation of the masticatory area of the cortex in the absence of rhythmical jaw movements activated the short-latency paucisynaptic corticotrigeminal pathways and evoked short-duration EPSPs and IPSPs in jaw opener and closer motoneurons, respectively. The same PnC-Gi stimulation that completely suppressed rhythmical MDPs, and stimulus-locked PSPs evoked by repetitive stimulation to the masticatory area of the cortex, produced an average reduction in PSP amplitude of 22 and 17% in jaw closer and opener motoneurons, respectively. 4. PnC-Gi stimulation produced minimal effects on the amplitude of the antidromic digastric field potential or on the intracellularly recorded antidromic digastric action potential. Moreover, PnC-Gi stimulation had little effect on jaw opener or jaw closer motoneuron membrane resting potentials in the absence of rhythmical jaw movements (RJMs). PnC-Gi stimulation produced variable effects on conductance pulses elicited in jaw opener and closer motoneurons in the absence of RJMs. 5. These results indicate that the powerful suppression of cortically evoked MDPs in opener and closer motoneurons during PnC-Gi stimulation is most likely not a result of postsynaptic inhibition of trigeminal motoneurons. It is proposed that this suppression is a result of suppression of activity in neurons responsible for masticatory rhythm generation.


1990 ◽  
Vol 26 (1) ◽  
pp. 63-72 ◽  
Author(s):  
R. C. Nageswara Rao ◽  
K. D. R. Wadia ◽  
J. H. Williams

SUMMARYThree short duration and one long duration groundnut genotypes, grown either ‘sole’ or as intercrops (in 1:1 ratios of the short duration with the long duration genotypes), were compared in four trials. The intercrop treatments resulted in Land Equivalent Ratios (LERs) of up to 1.25 for pod yield and total biomass despite moderate or severe water deficits at the end of the season. Specific combinations of genotypes were necessary to maximize the LER. The results indicate there is scope for achieving greater productivity in environments with a variable season length by growing late and early genotypes together in an intercrop system.


2013 ◽  
Vol 110 (4) ◽  
pp. 984-998 ◽  
Author(s):  
Wilsaan M. Joiner ◽  
Jordan B. Brayanov ◽  
Maurice A. Smith

The way that a motor adaptation is trained, for example, the manner in which it is introduced or the duration of the training period, can influence its internal representation. However, recent studies examining the gradual versus abrupt introduction of a novel environment have produced conflicting results. Here we examined how these effects determine the effector specificity of motor adaptation during visually guided reaching. After adaptation to velocity-dependent dynamics in the right arm, we estimated the amount of adaptation transferred to the left arm, using error-clamp measurement trials to directly measure changes in learned dynamics. We found that a small but significant amount of generalization to the untrained arm occurs under three different training schedules: a short-duration (15 trials) abrupt presentation, a long-duration (160 trials) abrupt presentation, and a long-duration gradual presentation of the novel dynamic environment. Remarkably, we found essentially no difference between the amount of interlimb generalization when comparing these schedules, with 9–12% transfer of the trained adaptation for all three. However, the duration of training had a pronounced effect on the stability of the interlimb transfer: The transfer elicited from short-duration training decayed rapidly, whereas the transfer from both long-duration training schedules was considerably more persistent (<50% vs. >90% retention over the first 20 trials). These results indicate that the amount of interlimb transfer is similar for gradual versus abrupt training and that interlimb transfer of learned dynamics can occur after even a brief training period but longer training is required for an enduring effect.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Julia H Indik ◽  
Mathias Zuercher ◽  
Karl B Kern ◽  
Ronald W Hilwig ◽  
Robert A Berg

It is known that defibrillation of ventricular fibrillation (VF) to a perfusing rhythm (ROSC) is more likely to occur in VF of short duration. It is unknown whether ROSC can be predicted by waveform characteristics in VF of short compared to long duration, apart from a consideration of time alone. VF was untreated for 2 minutes (N=10) or 8 minutes (N=10) in normal swine, after which a defibrillation shock was applied. Chest compressions for two minutes were allowed following but not prior to the shock to achieve a perfusing rhythm (ROSC). VF was analyzed from needle electrodes prior to the shock for amplitude spectral area (AMSA), slope, median frequency and bandwidth. Predictors of ROSC were determined by logistic regression. In VF of 2 minute duration 7 out of 10 swine achieved ROSC compared to 2 out 10 swine with VF of 8 minutes (P=0.025) and time was a significant predictor of ROSC (P=0.033). AMSA was significantly higher at 2 minutes (75 ± 18 mV-Hz) compared to 8 minutes (56±11 mV-Hz, p=0.007) as was slope (3.5±1 vs 2.6±0.5 mV/s, p=0.015). Bandwidth was slightly increased from 2.2±0.6 Hz at 2 minutes to 2.8±0.8 Hz at 8 minutes,(p=0.048), while median frequency was similar. However, no waveform characteristic was a significant predictor of ROSC, with substantial overlap in distributions between animals with and without ROSC. Duration of VF is an important determinant of the likelihood of achieving ROSC with defibrillation. Particularly in VF of short duration, VF waveform characteristics do not add to the predictability of achieving ROSC even though they may demonstrate a significant time evolution.


1998 ◽  
Vol 274 (3) ◽  
pp. E397-E402 ◽  
Author(s):  
Michael C. Hogan ◽  
Erica Ingham ◽  
S. Sadi Kurdak

It has been suggested that during a skeletal muscle contraction the metabolic energy cost at the onset may be greater than the energy cost related to holding steady-state force. The purpose of the present study was to investigate the effect of contraction duration on the metabolic energy cost and fatigue process in fully perfused contracting muscle in situ. Canine gastrocnemius muscle ( n = 6) was isolated, and two contractile periods (3 min of isometric, tetanic contractions with 45-min rest between) were conducted by each muscle in a balanced order design. The two contractile periods had stimulation patterns that resulted in a 1:3 contraction-to-rest ratio, with the difference in the two contractile periods being in the duration of each contraction: short duration 0.25-s stimulation/0.75-s rest vs. long duration 1-s stimulation/3-s rest. These stimulation patterns resulted in the same total time of stimulation, number of stimulation pulses, and total time in contraction for each 3-min period. Muscle O2 uptake, the fall in developed force (fatigue), the O2 cost of developed force, and the estimated total energy cost (ATP utilization) of developed force were significantly greater ( P < 0.05) with contractions of short duration. Lactate efflux from the working muscle and muscle lactate concentration were significantly greater with contractions of short duration, such that the calculated energy derived from glycolysis was three times greater in this condition. These results demonstrate that contraction duration can significantly affect both the aerobic and anaerobic metabolic energy cost and fatigue in contracting muscle. In addition, it is likely that the greater rate of fatigue with more rapid contractions was a result of elevated glycolytic production of lactic acid.


2005 ◽  
Vol 93 (3) ◽  
pp. 1223-1234 ◽  
Author(s):  
Daniel J. Tollin ◽  
Luis C. Populin ◽  
Jordan M. Moore ◽  
Janet L. Ruhland ◽  
Tom C. T. Yin

In oculomotor research, there are two common methods by which the apparent location of visual and/or auditory targets are measured, saccadic eye movements with the head restrained and gaze shifts (combined saccades and head movements) with the head unrestrained. Because cats have a small oculomotor range (approximately ±25°), head movements are necessary when orienting to targets at the extremes of or outside this range. Here we tested the hypothesis that the accuracy of localizing auditory and visual targets using more ethologically natural head-unrestrained gaze shifts would be superior to head-restrained eye saccades. The effect of stimulus duration on localization accuracy was also investigated. Three cats were trained using operant conditioning with their heads initially restrained to indicate the location of auditory and visual targets via eye position. Long-duration visual targets were localized accurately with little error, but the locations of short-duration visual and both long- and short-duration auditory targets were markedly underestimated. With the head unrestrained, localization accuracy improved substantially for all stimuli and all durations. While the improvement for long-duration stimuli with the head unrestrained might be expected given that dynamic sensory cues were available during the gaze shifts and the lack of a memory component, surprisingly, the improvement was greatest for the auditory and visual stimuli with the shortest durations, where the stimuli were extinguished prior to the onset of the eye or head movement. The underestimation of auditory targets with the head restrained is explained in terms of the unnatural sensorimotor conditions that likely result during head restraint.


2020 ◽  
Vol 10 (4) ◽  
pp. 70-97
Author(s):  
Boubaker Soltani ◽  
Afifa Ghenai ◽  
Nadia Zeghib

A relatively new paradigm for the Cloud-based software deployment is serverless computing. By adopting stateless loosely-coupled functions, the system can obtain many compositions for several purposes. Contrarily to monolithic approach, serverless computing facilitates the evolution of the applications, since the functions may be independently scheduled for reconstitution. Nevertheless, serverless computing dictates that function execution should be within a short duration (five minutes max in most Cloud platforms), after which the function is abruptly ended even if it has not completed its task. This leads to prevent functions requiring longer time from being adopted as Serverless functions. This paper deals with this drawback. It proposes a migration-based approach that promotes the execution of long-duration serverless functions: each running function that reaches the maximum time limit is repeatedly transferred to another cloud platform where it is carried on. At each migration step, the destination cloud is selected regarding the most relevant criteria.


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