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Sanchez-Moreno, Juan Francisco, Chris M. Mannaerts, Victor Jetten i Martin Löffler-Mang. "Rainfall kinetic energy–intensity and rainfall momentum–intensity relationships for Cape Verde". Journal of Hydrology 454-455 (sierpień 2012): 131–40. http://dx.doi.org/10.1016/j.jhydrol.2012.06.007.
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Mazurkiewicz, Karolina, i Marcin Skotnicki. "A determination of the synthetic hyetograph parameters for flow capacity assessment concerning stormwater systems". E3S Web of Conferences 45 (2018): 00053. http://dx.doi.org/10.1051/e3sconf/20184500053.
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The paper presents the results of an analysis of the influence of synthetic rainfall duration and location of rainfall intensity peak on the rate of the flood volume in surcharged storm sewers. The analyzed rainfalls had durations from 15 minutes to 180 minutes. It was assumed, that the rainfall peak location would change between the beginning and the end of the rainfall with increments of 10% of the rainfall duration. Outflow simulations were performed with the use of SWMM5.1.012 for three models of real urban catchments with surfaces from 1.6 km2 to 6.7 km2. An assessment of the influence of rainfall parameters was made on the basis of the flood volume rates. Short rainfalls with peaks located at the beginning of rainfall duration do not generate flooding. For other rainfalls it was found that for a specified rainfall duration the flood volume increases with the increase of time of the rainfall peak location. The maximum flood volume varied from 5% to 12% of the total runoff volume, depending on the catchment area, and is generated by the rainfall, whose intensity peak occurs right after the time corresponding to the flow time through the catchment.
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Su, Yan, Jun Bing Qiu i Yue Ting Du. "Rainfall Threshold of Rainfall-Induced Landslides Based on Laboratory Test". Applied Mechanics and Materials 353-356 (sierpień 2013): 1011–14. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.1011.
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A landslide model test under the artificial rainfall was built according to the rainfll-induced landslide in Fujian mountainous area. The rainfall intensity, the slope types (mainly on vegetation coverage) and the grade of side slope were the main factors in the test. The rainfall threshold of rainfall-induced landslide on shallow bedrock was obtained from the test. The relationship between the cumulative precipitation and slope angle and slope surface types was analyzed from the orthogonal experiment by multiple regression analysis. Results show that most slope failures are caused by the infiltration of rainwater. Conclusion show that when the slope angle and vegetation cover are given, critical hazard threshold can be predicted, and the corresponding landslide sliding time can be gained by combining with the rainfall intensity.
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KOTHYARI, U. C., S. K. VERMA i R. J. GARDE. "Rainfall intensity duration frequency analysis". MAUSAM 41, nr 3 (24.02.2022): 147–50. http://dx.doi.org/10.54302/mausam.v41i3.2750.
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In the present study the analysis of rainfall data compiled for eighty stations spread over several parts of India has been carried out for developing a general relationship for the estimation of short duration rainfall intensity.
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Balcerak, Ernie. "Understanding temporal rainfall intensity scaling". Eos, Transactions American Geophysical Union 93, nr 43 (23.10.2012): 436. http://dx.doi.org/10.1029/2012eo430013.
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Froehlich, David C. "Long-Duration–Rainfall Intensity Equations". Journal of Irrigation and Drainage Engineering 121, nr 3 (maj 1995): 248–52. http://dx.doi.org/10.1061/(asce)0733-9437(1995)121:3(248).
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Froehlich, David C. "Intermediate-Duration-Rainfall Intensity Equations". Journal of Hydraulic Engineering 121, nr 10 (październik 1995): 751–56. http://dx.doi.org/10.1061/(asce)0733-9429(1995)121:10(751).
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Sabino, Marlus, Adilson Pacheco de Souza, Eduardo Morgan Uliana, Luana Lisboa, Frederico Terra de Almeida i Cornélio Alberto Zolin. "Intensity-duration-frequency of maximum rainfall in Mato Grosso State". Ambiente e Agua - An Interdisciplinary Journal of Applied Science 15, nr 1 (3.02.2020): 1. http://dx.doi.org/10.4136/ambi-agua.2373.
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Intensive rainfall is an important meteorological variable that is of technical interest in hydraulic projects. This study therefore generated Intensity-Duration-Frequency equations (IDF) for 14 weather stations in Mato Grosso State, based on pluviograph analysis. Annual maximum rainfall data regarding 10-to-1440-minute long rainfall events were collected from digitized daily pluviographs. Data adherence to the generalized extreme value distribution (GEV) was checked through the Kolmogorov-Smirnov test at a 20% significance level. Next, the maximum probable rainfall for return periods such as 2, 5, 10, 20, 30, 50 and 100 years was calculated and the IDF equations were adjusted. The performance of the IDF equations was evaluated based on mean absolute error (MAE), root mean square error (RMSE), bias, Willmott's concordance index and Nash-Sutcliffe efficiency index (ENS). Adjusting the IDF equations was only possible for rainfall durations ranging from 10 to 360 min at each station due to the low frequency of longer rainfalls. High variation was present in parameters of the IDF equation and in maximum rainfall intensity between stations. The satisfactory performance of the models, as attested to by statistical indices, allows using IDF equations adjusted for rainfall durations from 10 to 360 min, and return periods from 2 to 100 years, in the regions of the Mato Grosso weather stations.
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Palamarchuk, L., K. Sokur i T. Zabolotska. "DYNAMICS OF RAINFALL INTENSITY AND MESOSTRUCTURAL CHARACTERISTICS OF THEIR FIELDS IN THE WARM PERIOD OF THE YEAR IN THE PLAIN PART OF UKRAINE". Hydrology, hydrochemistry and hydroecology, nr 4 (55) (2019): 95–111. http://dx.doi.org/10.17721/2306-5680.2019.4.8.
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The research deals with the structure of temporal changes in rainfall intensity and the spatial distribution of magnitude within separate processes of fallout of dangerous and heavy rainfalls in the warm season. The analysis based on the data from the Ukrainian hydrometeorological observation network (2005-2017) and the data obtained during a special scientific experiment (Kyiv, Bagrynova Mt., warm period 1969). It has been determined 97 cases of such rainfalls, the characteristics of their spatial distribution, seasonal and daily variations. For individual processes, on the basis of pluviometric measurements there were determined the maximum rainfall intensities, the time of their occurrence, the presence and the number of waves (periods) of rainfall amplification and their temporal and spatial parameters. The mass of rainwater per unit area and the volumetric intensity were calculated for moments of maximum intensity or amplification waves. The analysis of spatial and temporal fluctuations of intensity values within a separate process allowed to distinguish three types of rainfall during the warm period of the year: heavy precipitations (maximum intensities greater than 1 mm/min., such intensities more often observed at the beginning of the process; it notes the presence of one/two waves of amplification of rainfall with different amplitudes), slight precipitations (maximum intensities are approximately equal to 0.1 mm/min, several (3-5) waves of amplification of rainfall with small but equal amplitudes), and a “mix” of heavy and slight precipitations during the development of frontal stratus with so-called “flooded” convection (maximum intensities less than 1 mm / min; there are several waves of amplification of different amplitude). Conditions for the formation of heavy precipitations of the last type are the combination of mechanisms of thermal and dynamic convection, which is manifested in the enhancement of vertical lifting of air masses due to the blocking processes. It was made a comparison of the intensity and nature of precipitation in the current climatic period and in previous periods. It was found that the values of the maximum intensity for the same type of precipitation during the different observation periods practically coincide. Obviously, there is a zone of “upper limit” of the intensity of the processes of precipitation and moisture storage of clouds, which ensures the constant intensity of rainfall over time. There is some increase in number and length of waves of rainfall amplification, as well as an increase in the frequency of rainfalls with “flooded” convection. The research shows the recurrence of rainfall intensity for certain types within certain gradations of their values. On this basis an integral providing curve is created, which makes it possible to estimate the probability or recurrence of given precipitation intensity values at different levels of providing.
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Fontanazza, C. M., G. Freni, G. La Loggia i V. Notaro. "Uncertainty evaluation of design rainfall for urban flood risk analysis". Water Science and Technology 63, nr 11 (1.06.2011): 2641–50. http://dx.doi.org/10.2166/wst.2011.169.
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A reliable and long dataset describing urban flood locations, volumes and depths would be an ideal prerequisite for assessing flood frequency distributions. However, data are often piecemeal and long-term hydraulic modelling is often adopted to estimate floods from historical rainfall series. Long-term modelling approaches are time- and resource-consuming, and synthetically designed rainfalls are often used to estimate flood frequencies. The present paper aims to assess the uncertainty of such an approach and for suggesting improvements in the definition of synthetic rainfall data for flooding frequency analysis. According to this aim, a multivariate statistical analysis based on a copula method was applied to rainfall features (total depth, duration and maximum intensity) to generate synthetic rainfalls that are more consistent with historical events. The procedure was applied to a real case study, and the results were compared with those obtained by simulating other typical synthetic rainfall events linked to intensity–duration–frequency (IDF) curves. The copula-based multi-variate analysis is more robust and adapts well to experimental flood locations even if it is more complex and time-consuming. This study demonstrates that statistical correlations amongst rainfall frequency, duration, volume and peak intensity can partially explain the weak reliability of flood-frequency analyses based on synthetic rainfall events.
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Guan, Hongjie, i Rongjiang Cao. "Effects of biocrusts and rainfall characteristics on runoff generation in the Mu Us Desert, northwest China". Hydrology Research 50, nr 5 (30.08.2019): 1410–23. http://dx.doi.org/10.2166/nh.2019.046.
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Abstract How the presence of biocrusts regulates runoff generation in the Mu Us Desert is not well known. Runoff experiments under natural and artificial rainfalls and numerical simulations were conducted in semiarid environments to evaluate the effects of biocrust type and rainfall characteristics on runoff. The experimental results showed that the water drop penetration time (WDPT) of the moss-dominated biocrusts was 68.7% higher than that of lichen-dominated biocrusts. Nevertheless, the saturated hydraulic conductivity (Ks) for moss-dominated biocrusts was 72.7% lower than that for the lichen-dominated biocrusts. Runoff yield for moss-dominated biocrusts was significantly higher than that for lichen-dominated biocrusts. Runoff yield was mainly explained by rainfall amount (or maximum 5-min rainfall intensity, I5max) (P < 0.001) and WDPT (P = 0.001). The influences of biocrust type, rainfall intensity, and their interaction on runoff coefficient were significant at the probability level of 0.01. The results of numerical simulations concluded that surface runoff was generated for lichen- and moss-dominated biocrusts when rainfall intensity reached 73.5 and 49 mm h–1, respectively. Runoff coefficient in the moss-covered soil increased obviously when rainfall intensity changed from 49 to 73.5 mm h–1. The results suggest that runoff could be changed substantially under increasing trends in rainfall intensity in the Mu Us Desert.
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Boroghani, M., F. Hayavi i H. Noor. "Affectability of splash erosion by polyacrylamide application and rainfall intensity". Soil and Water Research 7, No. 4 (9.11.2012): 159–65. http://dx.doi.org/10.17221/45/2011-swr.
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Splash erosion is recognized as the first stage in a soil erosion process and results from the soil surface bombing by rain drops. At the moment when rain drops conflict with the soil surface, soil particles move and destruct the soil structure. Soil particles dispersed by rain drops and moved by runoff are two basic soil erosion processes. In this study, the effect of applying various amounts of polyacrylamide (PAM) (0, 0.2, 0.4 and 0.6 g/m<sup>2</sup>) on the quantity of splash erosion at three rainfall intensities of 65, 95 and 120 mm/h by using of FEL3 rainfall simulator was investigated in marly soil in a laboratory. Results indicated differences in the effects of various treatments with PAM at all rainfall intensities, such as 0.6 g/m<sup>2</sup> PAM had the maximum effect on the splash erosion control by reducing soil erosion by about 28.93%. But statistical results showed that the use of various amounts of PAM (0.2, 0.4 and 0.6 g/m<sup>2</sup>) for controlling splash erosion at various rain intensities to decrease splash erosion did not reveal a statistically significant difference. Therefore, the application of 0.2, 0.4 and 0.6 g/m<sup>2</sup> PAM reduced the splash erosion, however, there was no statistical difference among these application rates of PAM. Finally, the results of statistical analysis of different intensities showed that only at 120 mm/h there was a significant difference between PAM treatment and control treatment (0 g/m<sup>2</sup> PAM) in the splash erosion control. At this intensity, the treatment with 0.4 g/m<sup>2</sup> PAM produced a maximum effect on the splash erosion control with 40% in comparison with the control treatment.
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Hamaamin, Yaseen Ahmed Hamaamin. "Developing of Rainfall Intensity-Duration-Frequency Model for Sulaimani City". Journal of Zankoy Sulaimani - Part A 19, nr 3&4 (16.05.2016): 93–102. http://dx.doi.org/10.17656/jzs.10634.
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Brychta, Jiří, i Miloslav Janeček. "Determination of erosion rainfall criteria based on natural rainfall measurement and its impact on spatial distribution of rainfall erosivity in the Czech Republic". Soil and Water Research 14, No. 3 (27.05.2019): 153–62. http://dx.doi.org/10.17221/91/2018-swr.
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Rainfall erosivity is the main factor of the USLE or RUSLE equations. Its accuracy depends on recording precision and its temporal resolution, number of stations and their spatial distribution, length of recorded period, recorded period, erosion rainfall criteria, time step of rainfall intensity and interpolation method. This research focuses on erosion rainfall criteria. A network of 32 ombrographic stations, 1-min temporal resolution rainfall data, 35.6-year period and experimental runoff plots were used. We analysed 8951 rainfalls from ombrographic stations, 100 rainfalls and caused soil losses and runoffs from experimental runoff plots. Main parameter which influenced the number of erosion rainfalls was the precondition AND/OR which determines if conditions of rainfall total (H) have to be fulfilled simultaneously with rainfall intensity (I<sub>15</sub> or I<sub>30</sub>) or not. We proved that if parameters I<sub>15 </sub>> 6.25 mm/15 min AND H > 12.5 mm were fulfilled, then 84.2% of rainfalls caused soil loss > 0.5 t/ha and 73.7% ≥ 1 t/ha. In the case of precondition OR only 44.6% of rainfalls caused soil loss > 0.5 t/ha and 33.9% ≥ 1 t/ha. If the precondition AND was fulfilled, there were on average 75.5 rainfalls, average R factor for each rainfall was 21 MJ/ha·cm/h (without units below in the text, according international unit: 210 MJ/ha·mm/h) and average annual R factor was 45.4. In the case of precondition OR there were on average 279 rainfalls but average R factor for each rainfall was only 9.1 and average annual R factor was 67.4. Therefore if the precondition OR is used, R factor values are overestimated due to a high number of rainfalls with no or very low erosive potential. The resulting overestimated soil losses calculated using USLE/RUSLE subsequently cause an overestimation of financial expenses for erosion-control measures.
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Souza, Fábio Suano de, i Ciro Antonio Rosolem. "Rainfall intensity and Mepiquat Chloride persistence in cotton". Scientia Agricola 64, nr 2 (2007): 125–30. http://dx.doi.org/10.1590/s0103-90162007000200004.
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In some regions where cotton is grown in Brazil rainfall amounts to about 2,000 mm per year, which imposes a great risk for Mepiquat Chloride (MP) to be washed from cotton leaves before being absorbed. The objective of this research was to evaluate the MC persistence when applied on cotton plants submitted to different rain intensities after spraying. The treatments were three MC rates: 0, 15.0 and 30.0 g a.i. ha-1 and four simulated rainfalls, applied 90 minutes after MC spraying: 5, 10, 20 and 40 mm, plus a treatment without rain. Cotton plants of the cv. Delta Opal were grown in 12 L pots filled with an Haplortox. The experimental design was consisted of complete randomized blocks, in a factorial scheme, with four replicates. The evaluated parameters were: plant height, number of reproductive branches, dry matter weight, reproductive structures, retention and leaf area. The higher the rainfall the lower the effectiveness of the plant growth regulator in controlling plant height. A simulated rainfall as low as 5 mm occurring 90 minutes after MC application was enough to wash some of the plant growth regulator from cotton leaves.
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Manabe, Takeshi, Hisato Kobayashi, Toshio Ihara i Yoji Furuhama. "Spatial correlation coefficients of rainfall intensity inferred from statistics of rainfall intensity and rain attenuation". Annales des Télécommunications 41, nr 9-10 (wrzesień 1986): 463–69. http://dx.doi.org/10.1007/bf02998750.
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Moron, Vincent, Renaud Barbero, Hayley J. Fowler i Vimal Mishra. "Storm types in India: linking rainfall duration, spatial extent and intensity". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 379, nr 2195 (marzec 2021): 20200137. http://dx.doi.org/10.1098/rsta.2020.0137.
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We examine wet events (WEs) defined from an hourly rainfall dataset based on 64 gauged observations across India (1969–2016). More than 90% of the WEs (accounting for nearly 60% of total rainfall) are found to last less than or equal to 5 h. WEs are then clustered into six canonical local-scale storm profiles (CanWE). The most frequent canonical type (CanWE#1 and #2) are associated with very short and nominal rainfall. The remaining canonical WEs can be grouped into two broad families: (i) CanWE#3 and #5 with short (usually less than or equal to 3–4 h), but very intense rainfall strongly phase-locked onto the diurnal cycle (initiation peaks in mid-afternoon) and probably related to isolated thunderstorms or small mesoscale convective clusters (MCS), and (ii) CanWE#4 and #6 with longer and lighter rainfall in mean (but not necessarily for their maximum) and more independent of the diurnal cycle, thus probably related to larger MCSs or tropical lows. The spatial extent of the total rainfall received during each CanWE, as shown by IMERG gridded rainfall, is indeed smaller for CanWE#3 and #5 than for CanWE#4 and especially #6. Most of the annual maximum 1 hour rainfalls occur during CanWE#5. Long-term trend analysis of the June–September canonical WEs across boreal monsoonal India reveals an increase in the relative frequency of the convective storm types CanWE#3 and #5 in recent years, as expected from global warming and thermodynamic considerations. This article is part of a discussion meeting issue ‘Intensification of short-duration rainfall extremes and implications for flash flood risks’.
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Yilmaz, A. G., I. Hossain i B. J. C. Perera. "Effect of climate change and variability on extreme rainfall intensity–frequency–duration relationships: a case study of Melbourne". Hydrology and Earth System Sciences 18, nr 10 (15.10.2014): 4065–76. http://dx.doi.org/10.5194/hess-18-4065-2014.
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Abstract. The increased frequency and magnitude of extreme rainfall events due to anthropogenic climate change, and decadal and multi-decadal climate variability question the stationary climate assumption. The possible violation of stationarity in climate can cause erroneous estimation of design rainfalls derived from extreme rainfall frequency analysis. This may result in significant consequences for infrastructure and flood protection projects since design rainfalls are essential input for design of these projects. Therefore, there is a need to conduct frequency analysis of extreme rainfall events in the context of non-stationarity, when non-stationarity is present in extreme rainfall events. A methodology consisting of threshold selection, extreme rainfall data (peaks over threshold data) construction, trend and non-stationarity analysis, and stationary and non-stationary generalised Pareto distribution (GPD) models was developed in this paper to investigate trends and non-stationarity in extreme rainfall events, and potential impacts of climate change and variability on intensity–frequency–duration (IFD) relationships. The methodology developed was successfully implemented using rainfall data from an observation station in Melbourne (Australia) for storm durations ranging from 6 min to 72 h. Although statistically significant trends were detected in extreme rainfall data for storm durations of 30 min, 3 h and 48 h, statistical non-stationarity tests and non-stationary GPD models did not indicate non-stationarity for these storm durations and other storm durations. It was also found that the stationary GPD models were capable of fitting extreme rainfall data for all storm durations. Furthermore, the IFD analysis showed that urban flash flood producing hourly rainfall intensities have increased over time.
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Yilmaz, A. G., I. Hossain i B. J. C. Perera. "Effect of climate change and variability on extreme rainfall intensity–frequency–duration relationships: a case study of Melbourne". Hydrology and Earth System Sciences Discussions 11, nr 6 (16.06.2014): 6311–42. http://dx.doi.org/10.5194/hessd-11-6311-2014.
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Abstract. The increased frequency and magnitude of extreme rainfall events due to anthropogenic climate change, and decadal and multi-decadal climate variability question the stationary climate assumption. The possible violation of stationarity in climate can cause erroneous estimation of design rainfalls derived from extreme rainfall frequency analysis. This may result in significant consequences for infrastructure and flood protection projects since design rainfalls are essential input for design of these projects. Therefore, there is a need to conduct frequency analysis of extreme rainfall events in the context of non-stationarity, when non-stationarity is present in extreme rainfall events. A methodology consisting of, threshold selection, extreme rainfall data (peaks over threshold data) construction, trend and non-stationarity analysis, and stationary and non-stationary Generalized Pareto Distribution (GPD) models was developed in this paper to investigate trends and non-stationarity in extreme rainfall events, and potential impacts of climate change and variability on Intensity–Frequency–Duration (IFD) relationships. The developed methodology was successfully implemented using rainfall data from an observation station in Melbourne (Australia) for storm durations ranging from 6 min to 72 h. Although statistically significant trends were detected in extreme rainfall data for storm durations of 30 min, and 3 and 48 h, statistical non-stationarity tests and non-stationary GPD models did not indicate non-stationarity for these storm durations and other storm durations. It was also found that the stationary GPD models were capable of fitting extreme rainfall data for all storm durations. Furthermore, the IFD analysis showed that urban flash flood producing hourly rainfall intensities have increased over time.
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Kang, Young Bok, Bong Jin Kim, Soo Jin Park i Han Kuy Choi. "Estimation of Effective Rainfall Guidance Considering Infiltration Capacity-Rainfall Intensity". Journal of Korean Society of Hazard Mitigation 13, nr 1 (28.02.2013): 303–8. http://dx.doi.org/10.9798/kosham.2013.13.1.303.
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J. J. Stone, G. B. Paige i R. H. Hawkins. "Rainfall Intensity-Dependent Infiltration Rates on Rangeland Rainfall Simulator Plots". Transactions of the ASABE 51, nr 1 (2008): 45–53. http://dx.doi.org/10.13031/2013.24226.
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Yu, Pao-Shan, Tao-Chang Yang i Chin-Sheng Lin. "Regional rainfall intensity formulas based on scaling property of rainfall". Journal of Hydrology 295, nr 1-4 (sierpień 2004): 108–23. http://dx.doi.org/10.1016/j.jhydrol.2004.03.003.
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Istok, J. D., i L. Boersma. "Effect of antecedent rainfall on runoff during low-intensity rainfall". Journal of Hydrology 88, nr 3-4 (listopad 1986): 329–42. http://dx.doi.org/10.1016/0022-1694(86)90098-3.
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Yang, Xu, Xue-Yi You, Min Ji i Ciren Nima. "Influence factors and prediction of stormwater runoff of urban green space in Tianjin, China: laboratory experiment and quantitative theory model". Water Science and Technology 67, nr 4 (1.02.2013): 869–76. http://dx.doi.org/10.2166/wst.2012.600.
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The effects of limiting factors such as rainfall intensity, rainfall duration, grass type and vegetation coverage on the stormwater runoff of urban green space was investigated in Tianjin. The prediction equation of stormwater runoff was established by the quantitative theory with the lab experimental data of soil columns. It was validated by three field experiments and the relative errors between predicted and measured stormwater runoff are 1.41, 1.52 and 7.35%, respectively. The results implied that the prediction equation could be used to forecast the stormwater runoff of urban green space. The results of range and variance analysis indicated the sequence order of limiting factors is rainfall intensity > grass type > rainfall duration > vegetation coverage. The least runoff of green land in the present study is the combination of rainfall intensity 60.0 mm/h, duration 60.0 min, grass Festuca arundinacea and vegetation coverage 90.0%. When the intensity and duration of rainfall are 60.0 mm/h and 90.0 min, the predicted volumetric runoff coefficient is 0.23 with Festuca arundinacea of 90.0% vegetation coverage. The present approach indicated that green space is an effective method to reduce stormwater runoff and the conclusions are mainly applicable to Tianjin and the semi-arid areas with main summer precipitation and long-time interval rainfalls.
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Madsen, H., I. B. Gregersen, D. Rosbjerg i K. Arnbjerg-Nielsen. "Regional frequency analysis of short duration rainfall extremes using gridded daily rainfall data as co-variate". Water Science and Technology 75, nr 8 (16.02.2017): 1971–81. http://dx.doi.org/10.2166/wst.2017.089.
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A regional partial duration series (PDS) model is applied for estimation of intensity duration frequency relationships of extreme rainfalls in Denmark. The model uses generalised least squares regression to relate the PDS parameters to gridded rainfall statistics from a dense network of rain gauges with daily measurements. The Poisson rate is positively correlated to the mean annual precipitation for all durations considered (1 min to 48 hours). The mean intensity can be assumed constant over Denmark for durations up to 1 hour. For durations larger than 1 hour, the mean intensity is significantly correlated to the mean extreme daily precipitation. A Generalised Pareto distribution with a regional constant shape parameter is adopted. Compared to previous regional studies in Denmark, a general increase in extreme rainfall intensity for durations up to 1 hour is found, whereas for larger durations both increases and decreases are seen. A subsample analysis is conducted to evaluate the impacts of non-stationarities in the rainfall data. The regional model includes the non-stationarities as an additional source of uncertainty, together with sampling uncertainty and uncertainty caused by spatial variability.
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Chen, Rui, Ben Zhuo Zhang, Wei Dong Lei i Wen Bin Luo. "Response of Soil Suction to Heavy Rainfalls in a Tailings Dam". Advanced Materials Research 250-253 (maj 2011): 1681–85. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.1681.
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Rainfall is a significant factor leading to failure of tailings dams. The impact of rainfall on the instability of dams is mainly reflected in the variation of negative pore-water pressure (i.e. matric suction) during rainfall infiltration. However, there is a lack of study on the effects of rainfall on suction in tailings dams. In this study, the response of suction to artificial heavy rainfalls in a tailings dam was investigated. The effects of rainfall intensity and surface vegetation conditions on the response of suction were studied. It is found that suctions at a certain depth in the tailing dam were kept constant until the wetting front reached this depth. Once suctions were altered, the values dropped rapidly. The magnitude of suction change generally decreased with depth. Rainfall infiltration mainly occurred above the depth of 40 to 80 cm when subjected to rainstorm and heavy rainstorms. Larger rainfall intensity leads to shorter response time and to larger depth affected by rainfall, implying that the tailings dam is more susceptible to shallow landslide failure under larger rainfall intensity. The existing vegetation increases infiltrability significantly and then produces an adverse effect on the stability of the tailings dam. On the other hand, it is observed that the presence of vegetation greatly prevented surface erodibility and then decreases the possibility of debris flow.
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Panthou, Gérémy, Alain Mailhot, Edward Laurence i Guillaume Talbot. "Relationship between Surface Temperature and Extreme Rainfalls: A Multi-Time-Scale and Event-Based Analysis*". Journal of Hydrometeorology 15, nr 5 (25.09.2014): 1999–2011. http://dx.doi.org/10.1175/jhm-d-14-0020.1.
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Abstract Recent studies have examined the relationship between the intensity of extreme rainfall and temperature. Two main reasons justify this interest. First, the moisture-holding capacity of the atmosphere is governed by the Clausius–Clapeyron (CC) equation. Second, the temperature dependence of extreme-intensity rainfalls should follow a similar relationship assuming relative humidity remains constant and extreme rainfalls are driven by the actual water content of the atmosphere. The relationship between extreme rainfall intensity and air temperature (Pextr–Ta) was assessed by analyzing maximum daily rainfall intensities for durations ranging from 5 min to 12 h for more than 100 meteorological stations across Canada. Different factors that could influence this relationship have been analyzed. It appears that the duration and the climatic region have a strong influence on this relationship. For short durations, the Pextr–Ta relationship is close to the CC scaling for coastal regions while a super-CC scaling followed by an upper limit is observed for inland regions. As the duration increases, the slope of the relationship Pextr–Ta decreases for all regions. The shape of the Pextr–Ta curve is not sensitive to the percentile or season. Complementary analyses have been carried out to understand the departures from the expected Clausius–Clapeyron scaling. The relationship between dewpoint temperature and extreme rainfall intensity shows that the relative humidity is a limiting factor for inland regions, but not for coastal regions. Using hourly rainfall series, an event-based analysis is proposed in order to understand other deviations (super-CC, sub-CC, and monotonic decrease). The analyses suggest that the observed scaling is primarily due to the rainfall event dynamic.
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Rácz, Tibor. "On the correction of processed historical rainfall data of siphoned rainfall recorders". Időjárás 125, nr 3 (2021): 513–19. http://dx.doi.org/10.28974/idojaras.2021.3.9.
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Historical rainfall data registered by siphoned rainfall recorder (SRW) devices have been widely used for a long time in rainfall intensity investigations. A relatively known counting error of the SRW devices is the siphoning error, when the registration of rainfall is blocked temporarily, during the drainage of measure tank. This issue causes a systematic underestimation in the rainfall and rainfall intensity measurement results. To reduce its consequences, a data correction is crucial when SRW data are used, for example as a reference for climate comparison studies, or for proceeding of intensity-duration-frequency curves, etc. In this paper, a formula is presented to fix the siphonage error of SRW devices for historical rainfall data. The early measures were processed in a significant percentage of cases, and sometimes the original measurement results (registration ribbon) have been lost. An essential advantage of the presented formula is that it can be applied for these processed data, which show only the intensity of a known length time interval. For this correction, the average rainfall intensity and the length of the time window are needed, over the physical parameters of the SRW device. The data correction can provide a fixed value of the rainfall intensity, which is undoubtedly closer to the real average rainfall intensity. The importance of this formula is in the reprocessing and validation of the historical rainfall intensity data, measured by siphoned rainfall recorders.
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Back, Álvaro J., Augusto C. Pola, Nilzo I. Ladwig i Hugo Schwalm. "Erosive rainfall in the Rio do Peixe Valley in Santa Catarina, Brazil: Part II - Characteristics and temporal distribution pattern". Revista Brasileira de Engenharia Agrícola e Ambiental 21, nr 11 (listopad 2017): 780–84. http://dx.doi.org/10.1590/1807-1929/agriambi.v21n11p780-784.
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ABSTRACT Exploring the characteristics of erosive rain is an important aspect of studying erosive processes, and it allows researchers to create more natural and realistic hydrological simulations. The objective of this study was to analyse the characteristics of erosive rain and to determine the temporal distribution pattern of erosive rainfall in the Valley of Rio do Peixe in the state of Santa Catarina, Brazil. Daily pluviograms from the meteorological stations located in the cities Campos Novos, Videira, and Caçador in Santa Catarina from 1984 to 2014 were utilized for this study. By studying rainfall that is classified as erosive, the values of kinetic energy, maximum intensity in thirty minutes, and the value of EI30 erosivity index were determined. The rainfall was also classified according to the temporal distribution of rainfall in advanced, intermediate, and delayed patterns. Erosive rainfalls occur at a frequency of 53.3% advanced, 31.1% intermediate, and 15.6% delayed patterns. Erosive rainfall has an average precipitation amount of 25.5 mm, duration of 11.1 h, kinetic energy of 5.6 MJ ha-1, maximum intensity of 30 min of 17.7 mm h-1, and erosivity of 206.4 MJ mm ha-1 h-1. The highest frequency of erosive rainfall occurred in rainfalls lasting from 6 to 12 h (36.1%), followed by rainfalls lasting from 4 to 6 h (22.4%).
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Huang, Ching-Yuang, Cher-Wei Chou, Shu-Hua Chen i Jia-Hong Xie. "Topographic Rainfall of Tropical Cyclones past a Mountain Range as Categorized by Idealized Simulations". Weather and Forecasting 35, nr 1 (31.12.2019): 25–49. http://dx.doi.org/10.1175/waf-d-19-0120.1.
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Abstract Topographic rainfall induced by westbound tropical cyclones past an island mountain is investigated using an idealized Weather Research and Forecasting (WRF) Model. Idealized simulations with varying vortex core size R (100–250 km), vortex intensity Vmax (20–35 m s−1), and steering wind speed U (4–10 m s−1) are conducted. The results show that the geometric distributions of major rainfall over the island are not greatly sensitive to cloud microphysics schemes using either single momentum or double momentum. Major rainfall is produced over northeastern and southwestern slopes of the mountain for smaller U. As U is doubled, the rainfall, however, is considerably weakened or is present only over southwestern slopes. For smaller U, a bifurcation of island rainfall with a sudden change in intensity or geometric shifting exists within a tiny range of R or Vmax. When the bifurcation occurs with small track deviations, geometric distributions of major rainfall are also more sensitive to cloud microphysics schemes. Such formation of bifurcation or double-peak rainfall, however, is significantly reduced when the terrain size is doubled. Systematic experiments are conducted to relate the topographical rainfalls over the northern half, southern half, and the whole of the mountain slopes to varying R, Vmax, and U. Larger U tends to produce much larger southern rainfall than northern rainfall. The average and maximum rainfalls generally increase with increased Vmax, except for large R. The decrease of average rainfall and maximum rainfall with increased U is more evident for smaller R, while not necessarily true for larger R.
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Susilowati, Sofia W. Alisjahbana i Dyah Indriana Kusumastuti. "Estimation of Intensity Duration Frequency for Ungauged Basin in Lampung Province, Indonesia". International Journal of Design & Nature and Ecodynamics 17, nr 2 (27.04.2022): 297–302. http://dx.doi.org/10.18280/ijdne.170217.
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Frequency duration intensity (IDF) analysis was conducted to estimate the peak flow rate based on the minimum rainfall data collection station. Rainfall data used is data with high intensity that occurs in a short time from automatic rainfall recording stations. Currently, the availability and distribution of automatic rain recording stations in Lampung Province, Indonesia, are still limited. Therefore, this study aims to use the IDF approach in the ungauged basin area for areas with rainfall data that do not meet the hydrological analysis criteria by interpolating rainfall data from 126 manual rainfall measuring stations in Lampung Province, Indonesia. The research method includes analysis of rainfall intensity using the Mononobe equation at various durations and returns periods. Next, create a rainfall intensity map (isohyet) using ArcGis. Finally, compare the IDF analysis of daily rainfall data at 4 automatic rainfall gauge stations with the estimation results based on the intensity map (isohyet). Based on the results of data analysis, it is known that from the available 126 rainfall climatology stations, there are 113 rainfall climatology stations with complete data for 10 years and 13 rainfall climatology stations with incomplete data for 10 years. In addition, the study results show that 45.24% of the daily rainfall in Lampung province is in the low category, 53.97% is in the medium category, and 0.79% is in the high category. This study indicates that rainfall intensity data from climatological rainfall stations that do not meet the hydrological criteria can be found by interpolating rainfall intensity maps from the nearest rain climatology station that meet the hydrological analysis criteria. The relationship test of the actual rainfall intensity variable at 4 automatic rainfall gauge stations with the rainfall intensity from the map (isohyet) using MAPE showed satisfactory results.
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Xie, Zongxu, Hanbo Yang, Huafang Lv i Qingfang Hu. "Seasonal Characteristics of Disdrometer-Observed Raindrop Size Distributions and Their Applications on Radar Calibration and Erosion Mechanism in a Semi-Arid Area of China". Remote Sensing 12, nr 2 (12.01.2020): 262. http://dx.doi.org/10.3390/rs12020262.
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Raindrop size distributions (DSDs) are the microphysical characteristics of raindrop spectra. Rainfall characterization is important to: (1) provide information on extreme rate, thus, it has an impact on rainfall related hazard; (2) provide data for indirect observation, model and forecast; (3) calibrate and validate the parameters in radar reflectivity-rainfall intensity (Z-R) relationships (quantitative estimate precipitation, QPE) and the mechanism of precipitation erosivity. In this study, the one-year datasets of raindrop spectra were measured by an OTT Parsivel-2 Disdrometer placed in Yulin, Shaanxi Province, China. At the same time, four TE525MM Gauges were also used in the same location to check the disdrometer-measured rainfall data. The theoretical formula of raindrop kinetic energy-rainfall intensity (KE-R) relationships was derived based on the DSDs to characterize the impact of precipitation characteristics and environmental conditions on KE-R relationships in semi-arid areas. In addition, seasonal rainfall intensity curves observed by the disdrometer of the area with application to erosion were characterized and estimated. The results showed that after quality control (QC), the frequencies of raindrop spectra data in different seasons varied, and rainfalls with R within 0.5–5 mm/h accounted for the largest proportion of rainfalls in each season. The parameters in Z-R relationships (Z = aRb) were different for rainfall events of different seasons (a varies from 78.3–119.0, and b from 1.8–2.1), and the calculated KE-R relationships satisfied the form of power function KE = ARm, in which A and m are parameters derived from rainfall shape factor μ. The sensitivity analysis of parameter A with μ demonstrated the applicability of the KE-R formula to different precipitation processes in the Yulin area.
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Sirangelo, B., E. Ferrari i D. L. De Luca. "Occurrence analysis of daily rainfalls through non-homogeneous Poissonian processes". Natural Hazards and Earth System Sciences 11, nr 6 (14.06.2011): 1657–68. http://dx.doi.org/10.5194/nhess-11-1657-2011.
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Abstract. A stochastic model based on a non-homogeneous Poisson process, characterised by a time-dependent intensity of rainfall occurrence, is employed to explain seasonal effects of daily rainfalls exceeding prefixed threshold values. The data modelling has been performed with a partition of observed daily rainfall data into a calibration period for parameter estimation and a validation period for checking on occurrence process changes. The model has been applied to a set of rain gauges located in different geographical areas of Southern Italy. The results show a good fit for time-varying intensity of rainfall occurrence process by 2-harmonic Fourier law and no statistically significant evidence of changes in the validation period for different threshold values.
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SOUSA, MARCOS MAKEISON MOREIRA DE, HELBA ARAÚJO DE QUEIROZ PALÁCIO, EUNICE MAIA DE ANDRADE, JACQUES CARVALHO RIBEIRO FILHO i MATHEUS MAGALHÃES SILVA MOURA. "DETERMINANT PLUVIOMETRIC CHARACTERISTICS OF SEDIMENT TRANSPORT IN A CATCHMENT WITH THINNED VEGETATION IN THE TROPICAL SEMIARID". Revista Caatinga 33, nr 3 (wrzesień 2020): 785–93. http://dx.doi.org/10.1590/1983-21252020v33n322rc.
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ABSTRACT Knowing determinant factors of erosive process is essential to adopt soil conservationist and loss-mitigation measures. Therefore, the objective of this work was to assess the correlation between rainfall characteristics and sediment transport in the Semiarid region of Brazil. The study was conducted at the Iguatu Experimental Basin in the state of Ceará, Brazil, in a watershed with area of 1.15 ha. The vegetation was thinned by removal of plants with diameters below 10 cm, and the area remained with an arboreous cover of 60%. The following variables were evaluated from 2012 to 2016: rainfall depth (mm), rainfall duration (hours), maximum rainfall intensity in 5, 10, 15, 20, 30, 45, and 60 minutes (mm h-1), mean rainfall intensity (mm h-1), rainfall depth in the previous 5 days (mm), runoff depth (mm), and transported sediment (kg ha-1). The records showed 158 rainfall events, 27 with surface runoff and 24 with sediment transport. The correlations were investigated by multivariate analysis of principal components (PC). The model explained 84% of total variance with four PC-PC1, PC2, PC3, and PC4 were formed, respectively, for disaggregating power of rainfall on soil particles, represented by the rainfall intensities; soil water content; runoff depth and sediment transport; and rainfall duration and interval between rainfalls. The highest factorial weight was found for the maximum intensity in 20 minutes, indicating the need for further hydrological studies focused on this variable at basin scale in areas of the Semiarid region of Brazil subjected to thinning of the vegetation.
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Jan, Petrů, i Kalibová Jana. "Measurement and computation of kinetic energy of simulated rainfall in comparison with natural rainfall". Soil and Water Research 13, No. 4 (18.10.2018): 226–33. http://dx.doi.org/10.17221/218/2016-swr.
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Rainfall characteristics such as total amount and rainfall intensity (I) are important inputs in calculating the kinetic energy (KE) of rainfall. Although KE is a crucial indicator of the raindrop potential to disrupt soil aggregates, it is not a routinely measured meteorological parameter. Therefore, KE is derived from easily accessible variables, such as I, in empirical laws. The present study examines whether the equations which had been derived to calculate KE of natural rainfall are suitable for the calculation of KE of simulated rainfall. During the experiment presented in this paper, the measurement of rainfall characteristics was carried out under laboratory conditions using a rainfall simulator. In total, 90 measurements were performed and evaluated to describe the rainfall intensity, drop size distribution and velocity of rain drops using the Thies laser disdrometer. The duration of each measurement of rainfall event was 5 minutes. Drop size and fall velocity were used to calculate KE and to derive a new equation of time-specific kinetic energy (KE<sub>time</sub> – I). When comparing the newly derived equation for KE of simulated rainfall with the six most commonly used equations for KE<sub>time</sub> – I of natural rainfall, KE of simulated rainfall was discovered to be underestimated. The higher the rainfall intensity, the higher the rate of underestimation. KE of natural rainfall derived from theoretical equations exceeded KE of simulated rainfall by 53–83% for I = 30 mm/h and by 119–275% for I = 60 mm/h. The underestimation of KE of simulated rainfall is probably caused by smaller drops formed by the rainfall simulator at higher intensities (94% of all drops were smaller than 1 mm), which is not typical of natural rainfall.
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Sivapalan, Murugesu, i Günter Blöschl. "Transformation of point rainfall to areal rainfall: Intensity-duration-frequency curves". Journal of Hydrology 204, nr 1-4 (styczeń 1998): 150–67. http://dx.doi.org/10.1016/s0022-1694(97)00117-0.
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Krishnamurthy, Chandra Kiran B., Upmanu Lall i Hyun-Han Kwon. "Changing Frequency and Intensity of Rainfall Extremes over India from 1951 to 2003". Journal of Climate 22, nr 18 (15.09.2009): 4737–46. http://dx.doi.org/10.1175/2009jcli2896.1.
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Abstract Using a 1951–2003 gridded daily rainfall dataset for India, the authors assess trends in the intensity and frequency of exceedance of thresholds derived from the 90th and the 99th percentile of daily rainfall. A nonparametric method is used to test for monotonic trends at each location. A field significance test is also applied at the national level to assess whether the individual trends identified could occur by chance in an analysis of the large number of time series analyzed. Statistically significant increasing trends in extremes of rainfall are identified over many parts of India, consistent with the indications from climate change models and the hypothesis that the hydrological cycle will intensify as the planet warms. Specifically, for the exceedance of the 99th percentile of daily rainfall, all locations where a significant increasing trend in frequency of exceedance is identified also exhibit a significant trend in rainfall intensity. However, extreme precipitation frequency over many parts of India also appears to exhibit a decreasing trend, especially for the exceedance of the 90th percentile of daily rainfall. Predominantly increasing trends in the intensity of extreme rainfall are observed for both exceedance thresholds.
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Ran, Qihua, Feng Wang i Jihui Gao. "Modelling Effects of Rainfall Patterns on Runoff Generation and Soil Erosion Processes on Slopes". Water 11, nr 11 (25.10.2019): 2221. http://dx.doi.org/10.3390/w11112221.
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Rainfall patterns and landform characteristics are controlling factors in runoff and soil erosion processes. At a hillslope scale, there is still a lack of understanding of how rainfall temporal patterns affect these processes, especially on slopes with a wide range of gradients and length scales. Using a physically-based distributed hydrological model (InHM), these processes under different rainfall temporal patterns were simulated to illustrate this issue. Five rainfall patterns (constant, increasing, decreasing, rising-falling and falling-rising) were applied to slopes, whose gradients range from 5° to 40° and projective slope lengths range from 25 m to 200 m. The rising-falling rainfall generally had the largest total runoff and soil erosion amount; while the constant rainfall had the lowest ones when the projective slope length was less than 100 m. The critical slope of total runoff was 15°, which was independent of rainfall pattern and slope length. However, the critical slope of soil erosion amount decreased from 35° to 25° with increasing projective slope length. The increasing rainfall had the highest peak discharge and erosion rate just at the end of the peak rainfall intensity. The peak value discharges and erosion rates of decreasing and rising-falling rainfalls were several minutes later than the peak rainfall intensity.
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Harisuseno, Donny. "Study on the Suitability of Rainfall Intensity Formula and Intensity Duration Frequency Curve (IDF) in the Campus Area of Universitas Brawijaya, Malang". MEDIA KOMUNIKASI TEKNIK SIPIL 26, nr 2 (2.02.2021): 247–57. http://dx.doi.org/10.14710/mkts.v26i2.31210.
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Rainfall intensity known as an essential variable in rainfall-runoff transformation. Flood events occurred in 2017 at Brawijaya University campus caused by high intensity and landuse change in campus's internal and external environment. The study aims to examine performance of several empirical formulas in estimating rainfall intensity, investigating characteristic of each empirical formula’s contant due to varying return period (Tr), and determining appropriate Intensity Duration Frequency (IDF) curve. The formula of Sherman, Talbot, and Ishiguro was employed to obtain empirical intensity, while intensity on varying return period was calculated using Log Pearson Type III. The proposed rainfall intensity formula was selected through comparison between empirical intensity with those from observation according to criteria of relative error (KR), Nash Sutcliffe Efficiency (NSE), and Peak Weight Root Mean Square Error (PWRMSE). The Sherman formula showed best performance in estimating rainfall intensity as indicated by low value of KR and PWRMSE, followed by NSE close to one. The constant of empirical formula “a” was directly proportional with increasing of Tr; conversely, constant “b” and “n” were inverse with Tr. The validation result of Sherman formula demonstrated that the formula showed good reliability, thus recommended to estimate intensity and IDF curve in the study area.
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Floris, M., A. D'Alpaos, C. Squarzoni, R. Genevois i M. Marani. "Recent changes in rainfall characteristics and their influence on thresholds for debris flow triggering in the Dolomitic area of Cortina d'Ampezzo, north-eastern Italian Alps". Natural Hazards and Earth System Sciences 10, nr 3 (26.03.2010): 571–80. http://dx.doi.org/10.5194/nhess-10-571-2010.
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Abstract. In this paper, we examine variations in climate characteristics near the area of Cortina d'Ampezzo (Dolomites, Eastern Italian Alps), with particular reference to the possible implications for debris-flow occurrence. The study area is prone to debris-flow release in response to summer high-intensity short-duration rainfalls and, therefore, it is of the utmost importance to investigate the potential increase in debris-flow triggering rainfall events. The critical rainfall threshold is agreed to be a crucial triggering factor for debris-flows. Data from a monitoring system, placed in a catchment near Cortina (Acquabona), show that debris-flows were triggered by rainfalls with peak rainfall intensities ranging from 4.9 to 17.4 mm/10 min. The analyses of meteorological data, collected from 1921 to 1994 at several stations in the study area, show a negative trend of annual rainfall, a considerable variation in the monthly rainfall distribution, and an increase in the temperature range, possibly related to global climate changes. Moreover, high-intensity and short-duration rainfall events, derived from data collected from 1990 and 2008, show an increase in exceptional rainfall events. The results obtained in a peak-over-threshold framework, applied to the rainfall data measured at the Faloria rain gauge station from 1990 to 2008, clearly show that the interarrival time of over-threshold events computed for different threshold values decreased in the last decade. This suggests that local climatic changes might produce an increase in the frequency of rainfall events, potentially triggering debris flows in the study area.
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Silva, Luciele Vaz da, Derblai Casaroli, Adão Wagner Pêgo Evangelista, José Alves Júnior i Rafael Battisti. "Rainfall Intensity-Duration-Frequency Relationships for Risk Analysis in the Region of Matopiba, Brazil". Revista Brasileira de Meteorologia 34, nr 2 (czerwiec 2019): 247–54. http://dx.doi.org/10.1590/0102-77863340239.
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Abstract The region of study was MATOPIBA, located in the north of Brazilian Savanna biome (Cerrado), encompassing part of north/northeast of Brazil. The region has been gaining prominence in the last years due to the expansion of agricultural over this area. The aims of this study were: to adjust parameters for rainfall intensity-duration-frequency; and to identify the most vulnerable agricultural areas to erosion based on erosivity and erodibility. The rainfall intensity-duration-frequency function were adjusted using series of maximum annual rainfall event from 105 rainfall gauges. Gumbel model was the most efficient to simulate the maximum rainfall intensity, where these data were used to adjusted the rainfall intensity-duration-frequency model based on K, a, b and c parameters. The most rainfall gauges showed intensity between 51 and 80 mm h-1 and 81 and 120 mm h-1, respectively, for return period of 2 and 100 years with rainfall duration of 30 minutes. The higher rainfall intensity was observed mainly in the central-north of the region associated with rainfall systems. The rainfall intensity showed a huge capacity to cause soil erosion based on the erosivity energy, while the moderate erodibility was observed for areas with Ferralsols and Leptosols and low erodibility for areas with Arenosols.
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Li, Mingyan, Xiao Guo, Song Zhao, Lele Liu, Zhenwei Xu, Ning Du i Weihua Guo. "Robinia pseudoacacia Seedlings Are More Sensitive to Rainfall Frequency Than to Rainfall Intensity". Forests 13, nr 5 (16.05.2022): 762. http://dx.doi.org/10.3390/f13050762.
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Climate change causes the global redistribution of precipitation, yet little is known about the effects of the changes in precipitation intensity and frequency on the seedlings of wood trees in warm temperate forests. In this study, we focused on the effects of variability in both the intensity and frequency of water supply on the physiological traits, biomass, and growth of an important plantation wood species, Robinia pseudoacacia. In the greenhouse, we exposed R. pseudoacacia seedlings to three rainfall intensity and three rainfall frequency treatments. The results from the 62-day experiment revealed that lower rainfall intensity and frequency significantly reduced the photosynthetic performance, growth, and biomass of the tree seedlings. In lower rainfall intensity and frequency conditions, the seedlings had improved water absorption and utilization by increasing the water use efficiency and root shoot ratio, and reduced water consumption by defoliating the compound leaves of the lower crown. More importantly, we found that R. pseudoacacia seedlings were more sensitive to rainfall frequency than to rainfall intensity. Therefore, our results suggest that increasing the irrigation water, especially irrigation frequency, could better facilitate the survival and growth of R. pseudoacacia seedlings and eventually promote the process of vegetation restoration in the future global climate change context.
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Chen, Yi-Ru, Bofu Yu i Graham Jenkins. "Secular variation in rainfall and intensity–frequency–duration curves in Eastern Australia". Journal of Water and Climate Change 4, nr 3 (18.04.2013): 244–51. http://dx.doi.org/10.2166/wcc.2013.138.
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Rainfall intensity–frequency–duration curves are used extensively for storm runoff estimation. It is generally assumed that rainfall intensity would increase with global warming irrespective of the underlying changes to rainfall. This study analyzed rainfall and temperature from six sites in Eastern Australia. Two non-overlapping 30-year periods with the greatest difference in the mean annual rainfall were selected at each of the six sites to test for significant changes in the mean annual temperature and rainfall. Changes in the mean rainfall intensity for different frequencies of occurrence and storm durations for each site were also analyzed. Temperature has increased at all sites, and significantly at five out of the six sites. The mean annual rainfall has significantly changed between the two non-overlapping periods at the sites with the exception of Cairns (latitude – 16.87° south). The changes in rainfall intensity for longer durations (≥1 h) positively correlate with changes in the mean annual rainfall. There is evidence to suggest that the 6 min rainfall intensity would increase irrespective of the changes in the mean annual rainfall.
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Li, Jian, i Rucong Yu. "A Method to Linearly Evaluate Rainfall Frequency–Intensity Distribution". Journal of Applied Meteorology and Climatology 53, nr 4 (kwiecień 2014): 928–34. http://dx.doi.org/10.1175/jamc-d-13-0272.1.
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AbstractThis study presents a method to linearly evaluate the rainfall frequency–intensity distribution, which is an important component of climatological rainfall characteristics. To grasp and represent the key information of the rainfall frequency distribution by intensity, a two-parameter double exponential function is formulated and fitted to the hourly rainfall observation at each station. The values of the two parameters are estimated by transforming the distribution to a linear pattern. The two parameters determine the location and shape of the fitted distribution curve, and they have different modulating effects in different intensity categories, one governing the low-intensity section and the other dominating the intense rainfall. Through analysis of the estimated parameters, essential features of rainfall distribution can be obtained and assessed. The proposed method is applied to analyze the climatology and long-term variation of the late-summer rainfall in China. It is found that topography and monsoon circulation are two major factors controlling the rainfall frequency–intensity distribution. At stations with high surface altitudes and complex orography, the frequency of light rain is extremely high and the number of intense rainfall events is relatively small. In the plain areas of eastern China, especially those influenced by the main monsoon rain belt, heavy rainfall is more frequent. By tracking the displacement of the parameter pairs, the decadal changes in rainfall frequency–intensity distribution can be clearly visualized and evaluated on a plane constructed by the two parameters. The southern flooding and northern drought pattern can be attributed to the changes in light and moderate rainfall, while the intense rainfall exhibits opposite trends.
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Sansom, John, i James A. Renwick. "Climate Change Scenarios for New Zealand Rainfall". Journal of Applied Meteorology and Climatology 46, nr 5 (1.05.2007): 573–90. http://dx.doi.org/10.1175/jam2491.1.
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Abstract In terms of the effects of future climate change upon society, some of the most important parameters to estimate are associated with changing risks of extreme rainfall events, both floods and droughts. However, such aspects of the climate system are hard to estimate well using general circulation models (GCMs)—in particular, for a small mountainous landmass such as New Zealand. This paper describes a downscaling technique using broad-scale changes simulated by GCMs to select past analogs of future climate. The analog samples are assumed to represent an unbiased sample of future rainfall and are used to develop detailed descriptions of rainfall statistics using hidden semi-Markov models of rainfall breakpoint information. Such models are used to simulate long synthetic rainfall time series for comparison with the historical record. Results for three New Zealand sites show overall increases in rainfall with climate change, brought about largely by an increased frequency of rainfall events rather than an increase in rainfall intensity. There was little evidence for significant increases in high-intensity short-duration rainfalls at any site. Such results suggest that, although regional increases of rainfall are consistent with expected future climate changes, it may be that circulation changes, rather than temperature (and vapor pressure) changes, will be the more important determinant of future rainfall distributions, at least for the coming few decades.
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Chen, Yi-Ru, Bofu Yu i Graham Jenkins. "Secular Variation in Rainfall Intensity and Temperature in Eastern Australia". Journal of Hydrometeorology 14, nr 4 (1.08.2013): 1356–63. http://dx.doi.org/10.1175/jhm-d-12-0110.1.
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Abstract It is generally assumed that rainfall intensity will increase with temperature increase, irrespective of the underlying changes to the average rainfall. This study documents and investigates long-term trends in rainfall intensities, annual rainfall, and mean maximum and minimum temperatures using the Mann–Kendall trend test for nine sites in eastern Australia. Relationships between rainfall intensities at various durations and 1) annual rainfall and 2) the mean maximum and minimum temperatures were investigated. The results showed that the mean minimum temperature has increased significantly at eight out of the nine sites in eastern Australia. Changes in annual rainfall are likely to be associated with changes in rainfall intensity at the long duration of 48 h. Overall, changes in rainfall intensity at short durations (<1 h) positively correlate with changes in the mean maximum temperature, but there is no significant correlation with the mean minimum temperature and annual rainfall. Additionally, changes in rainfall intensity at longer durations (≥1 h) positively correlate with changes in the mean annual rainfall, but not with either mean maximum or minimum temperatures for the nine sites investigated.
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Ma, Yichun, Zhongwu Li, Liang Tian, Yifan Yang, Wenqing Li, Zijuan He, Xiaodong Nie i Yaojun Liu. "Erosion of Granite Red Soil Slope and Processes of Subsurface Flow Generation, Prediction, and Simulation". International Journal of Environmental Research and Public Health 20, nr 3 (24.01.2023): 2104. http://dx.doi.org/10.3390/ijerph20032104.
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A deeper understanding of the rainfall–flow processes can improve the knowledge of the rain-driven erosional processes in coarse-textured agricultural soil. In this study, on the red soil slope farmland developed from weathered granite, a simulated rainfall experiment was conducted to study the characteristics of rainfall redistribution, the processes of surface–subsurface flow generation and prediction, and sediment production. Rainfalls with three intensities of 45, 90, and 135 mm h−1 with a duration of 90 min were applied to the weathered granite red soil with the slope gradient of 10°. Under 45 mm h−1 rainfall intensity, the output of rainwater was composed by subsurface flow and bottom penetration, accounting for 35.80% and 39.01% of total rainfall, respectively. When the rainfall intensities increased to 90 and 135 mm h−1, the surface flow became the main output of rainwater, accounting for 83.94% and 92.42%, respectively. Coarsened soil exhibited strong infiltration-promoting but poor water-storage capacities under light rainfalls. With an increased rainfall intensity, the surface flow coefficient increased from 19.87% to 92.42%, while the amount of subsurface flow and bottom penetration decreased by 1.3 and 6.2 L, respectively. For sediment production, the sediment concentration was raised from 1.39 to 7.70 g L−1, and D10, D50, and D90 increased by 1.50, 1.83, and 1.40 times, respectively. The content of coarse particles (>1 mm) in surface soil increased by 12%, while the content of fine particles (<0.5 mm) decreased by 9.6%. Under strong rainfalls, severe soil and water loss, coarsening soil surface, and large loss of fine particles became major problems. During rainfall, the subsurface flow and bottom penetration could be predicted well through quadratic equations of rainfall time, which transformed into time-dependent exponential functions after rainfall. The results provide a theoretical basis and data reference for soil erosion prevention and water management in coarse-textured agricultural lands.
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Shin, Seung Sook, Sang Deog Park i Byoung Koo Choi. "Universal Power Law for Relationship between Rainfall Kinetic Energy and Rainfall Intensity". Advances in Meteorology 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/2494681.
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Rainfall kinetic energy has been linked to linear, exponential, logarithmic, and power-law functions using rainfall intensity as an independent variable. The power law is the most suitable mathematical expression used to relate rainfall kinetic energy and rainfall intensity. In evaluating the rainfall kinetic energy, the empirical power laws have shown a larger deviation than other functions. In this study, universal power law between rainfall kinetic energy and rainfall intensity was proposed based on the rainfall power theory under an ideal assumption that drop-size is uniformly distributed in constant rainfall intensity. An exponent of the proposed power law was 11/9 and coefficient was estimated at 10.3 from the empirical equations of the existing power-law relation. The rainfall kinetic energy calculated by universal power law showed >95% concordance rate in comparison to the average values calculated from exponential and logarithmic functions used in soil erosion model such as USLE, RUSLE, EUROSEM, and SEMMA and <5% relative difference as compared to the average rainfall kinetic energies calculated by other empirical functions. Therefore, it is expected that power law of ideal assumption may be utilized as a universal power law in evaluating rainfall kinetic energy.
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Limantara, Lily Montarcih, Donny H. Harisuseno i Vita A. K. Dewi. "Modelling of rainfall intensity in a watershed: A case study in Amprong watershed, Kedungkandang, Malang, East Java of Indonesia". Journal of Water and Land Development 38, nr 1 (1.09.2018): 75–84. http://dx.doi.org/10.2478/jwld-2018-0044.
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AbstractAnalysis of rainfall intensity with specific probability is very important to control the negative impact of rainfall occurrence. Rainfall intensity (I), probability (p) and return period (T) are very important variables for the discharge analysis. There are several methods to estimate rainfall intensity, such as Talbot, Sherman, and Ishiguro. The aim of this research is to develop equation model which can predict rainfall intensity with specific duration and probability. The equation model is compared with the other methods. The result of rainfall intensity model with the value of correlation >0.94 and Nash–Sutcliffe coefficient >99 is quite good enough if compared with the observation result. For specific return period, the modelling result is less accurate which is most likely caused by election of duration. Advanced research in other location indicates that short duration gives the better result for rainfall intensity modelling, which is shown by the decreasing average value of mean absolute error (MAE) from 12.963 to 8.26.
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Yuan, Hao, Weilin Xu, Rui Li, Yanzhang Feng i Yafeng Hao. "Spatial Distribution Characteristics of Rainfall for Two-Jet Collisions in Air". Water 10, nr 11 (7.11.2018): 1600. http://dx.doi.org/10.3390/w10111600.
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Many researchers have studied the energy dissipation characteristics of two-jet collisions in air, but few have studied the related spatial rainfall distribution characteristics. In this paper, in combination with a model experiment and theoretical study, the spatial distributions of rainfall intensity of two-jet collisions, with different collision angles and flow ratios, are systematically studied. The experimental results indicated that a larger collision angle corresponds to a larger rainfall intensity distribution. The dimensionless maximum rainfall intensity sharply decreased with the flow ratio, while the maximum rainfall intensity slightly increased when the flow ratio was greater than 1.0. A theoretical equation to compute the location of maximum rainfall intensity is presented. The range of rainfall intensity distribution sharply increased with the flow ratio. When the flow ratio was greater than 1.0, the range of longitudinal distribution slightly increased, whereas the lateral distribution remained unchanged or slowly decreased. A formula to calculate the boundary lines of the x-axis is proposed.