scholarly journals Floods in Southern Thailand in December 2016 and January 2017

2018 ◽  
Vol 13 (4) ◽  
pp. 793-803
Author(s):  
Taichi Tebakari ◽  
Sanit Wongsa ◽  
Yoshiaki Hayashi ◽  
◽  
◽  
...  
Keyword(s):  
Large Scale ◽  
Field Survey ◽  
Rainfall Data ◽  
Precipitation Event ◽  
Rain Gauges ◽  
Southern Thailand ◽  
Satellite Rainfall ◽  
Precipitation Phenomena ◽  
Precipitation Events

A large scale flood disaster occurred in Southern Thailand in December, 2016 and January, 2017, resulting in 95 deaths. The majority of the 15 provinces in Southern Thailand suffered from the disaster and extensive, long-term damage was caused which distinguished this flood event from previous flood disasters. This paper reports the findings of a field survey conducted in February, 2017 and analyzes the precipitation phenomena by using ground rainfall data as well as satellite rainfall data because there were not enough ground rain gauges set in this region. Results revealed that this precipitation event had the highest intensity out of all precipitation events occurring over the last 11 years.

Spatially-distributed IDF curves for Center-Southern Chile using IMERG

2020 ◽  
Author(s):  
Mauricio Zambrano-Bigiarini ◽  
Cristóbal Soto Escobar ◽  
Oscar M. Baez-Villanueva
Keyword(s):  
Spatial Distribution ◽  
Rain Gauge ◽  
Temporal Scales ◽  
Rain Gauges ◽  
South Central ◽  
Idf Curves ◽  
The Impact ◽  
Term Rain ◽  
Precipitation Events

<p>The Intensity-Duration-Frequency (IDF) curves are crucial for urban drainage design and to mitigate the impact of extreme precipitation events and floods. However, many regions lack a high-density network of rain gauges to adequately characterise the spatial distribution of precipitation events. In this work we compute IDF curves for the South-Central Chilean region (26-56°S) using the latest version of the Integrated Multi-satellitE Retrievals for GPM (IMERGv06B) for 2001-2018, with a spatial resolution of 0.10° and half-hourly temporal frequency.</p><p><br>First, we evaluated the performance of IMERGv06B against 344 rain gauge stations at daily, monthly and annual temporal scales using a point-to-pixel approach. The modified Kling-Gupta efficiency (KGE’) and its components (linear correlation, bias, and variability ratio) were selected as continuous indices of performance. Secondly, we fit maximum precipitation intensities from 14 long-term rain gauge stations to three probability density functions (Gumbel, Log-Pearson Type III, and GEV II) to evaluate: i) the impact of using 15-year rainfall time series in the computation of IDF curves instead of using the typical long-term periods (~ 30 years); and ii) to select the best distribution function for the study area. The Gumbel distribution was selected to obtain the maximum annual intensities for each grid-cell within the study area for 12 durations (0.5, 1, 2, 4, 6, 8, 10, 12, 18, 24, 48, and 72 h) and 6 return periods (T=2, 5, 10, 25, 50, and 100 years).</p><p><br>The application of the Wilcoxon Mann-Whitney test indicates that differences between IDF curves obtained from 15 years of records at the 14 long-term rain gauges and those derived from 25 years of record (or more) are not statistically significant, and therefore, 15 years of record are enough (although not optimal) to compute the IDF curves. Also, our results show that IMERGv06B is able to represent the spatial distribution of precipitation at daily, monthly and annual temporal scales over the study area. Moreover, the obtained precipitation intensities showed high spatial variability, mainly over the Near North (26.0-32.2°S) and the Far South (43.7-56.0°S). Additionally, the intensities from Central Chile (32.2-36.4°S) to the Near South (36.4-43.7°S) were systematically higher compared to the intensities described in older official governmental reports, suggesting an increase in precipitation intensities during recent decades.</p>

Rainfall data monitoring and application for urban hydrology in the Czech Republic

1998 ◽  
Vol 37 (11) ◽  
pp. 91-96 ◽  
Author(s):  
J. Krejcik ◽  
V. Krejci ◽  
S. Musilová ◽  
D. Stransky
Keyword(s):  
Czech Republic ◽  
Rainfall Data ◽  
Advanced Technology ◽  
Urban Hydrology ◽  
Urban Drainage ◽  
Sewer System ◽  
The Czech Republic ◽  
Rain Gauges ◽  
Technology Applications

With respect to increasing number of advanced technology applications for urban drainage projects in the Czech republic the requirements for relevant rain data become more important. Two research projects related to measurement, evaluation and application of rainfall data for urban hydrology purposes were launched. Suitable measuring equipment and their reliability have been studied and evaluated. The needs of high density of rain gauges for single event investigation of sewer system have been verified. The spatial distribution of rainfall doesnt influence statistical evaluation of the effects obtained by long term simulation significantly. The needs for rainfall data will be proposed for the master plan of urban drainage in Prague.

scholarly journals Dynamics of widespread extreme precipitation events and the associated large-scale environment using AMeDAS and JRA-55 data

2021 ◽  
pp. 1-44
Author(s):  
Ryosuke Shibuya ◽  
Yukari Takayabu ◽  
Hirotaka Kamahori
Keyword(s):  
Extreme Precipitation ◽  
Large Scale ◽  
Diabatic Heating ◽  
Height Anomaly ◽  
East China ◽  
Precipitation Event ◽  
Production Term ◽  
Extreme Precipitation Events ◽  
Western Japan ◽  
Precipitation Events

AbstractThis study examines disastrous historical precipitation cases that generate extreme precipitation simultaneously over a wide area in Japan (as in July 2018), defined as widespread extreme precipitation events. A statistically significant large-scale environment conducive for widespread extreme precipitation events over western Japan is investigated based on composite analysis. During a widespread precipitation event, a zonally elongated positive anomaly of the column-integrated water vapor extends from East China to western Japan. In the lower troposphere, a dipole of a geopotential height anomaly exists with positive and negative values at the east and west of the precipitation area, respectively. It is found that the negative geopotential anomaly is enhanced over East China at two days before the event and moves toward the precipitating area mainly due to the PV production term by diabatic heating, in analogy of a diabatic Rossby wave. The temporal evolution of the dynamical forced vertical velocity is well in phase with that the PV production term, inferring the importance of the coupling between the dynamical forced motion and diabatic heating. This result provides a physical understanding of the reason why both the background moisture and the baroclinicity are essential in the composited atmospheric fields and another view to the importance of the feedback parameter between the dynamical motion and diabatic heating.

scholarly journals Investigating Spatial Downscaling of Satellite Rainfall Data for Streamflow Simulation in a Medium-Sized Basin

2009 ◽  
Vol 10 (4) ◽  
pp. 1063-1079 ◽  
Author(s):  
Sayma Rahman ◽  
Amvrossios C. Bagtzoglou ◽  
Faisal Hossain ◽  
Ling Tang ◽  
Lance D. Yarbrough ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Rainfall Variability ◽  
Tropical Rainfall Measuring Mission ◽  
Hydrologic Model ◽  
Rainfall Data ◽  
Streamflow Prediction ◽  
Satellite Rainfall ◽  
Spatial Downscaling ◽  
Streamflow Simulation

Abstract The objective of this study was to investigate spatial downscaling of satellite rainfall data for streamflow prediction in a medium-sized (970 km2) river basin prone to flooding. The spatial downscaling scheme used in the study was based on the principle of scale invariance. It reproduced the rainfall variability at finer scales while being conditioned on the large-scale rainfall. Two Tropical Rainfall Measuring Mission (TRMM)-based real-time global satellite rainfall products were analyzed: 1) the infrared (IR)-based 3B41RT product available at 1 hourly and 0.25° scales and 2) the combined passive microwave (PMW) and IR-based 3B42RT product available at 3 hourly and 0.25° scales. The conceptual Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) was used for the simulation of streamflow. It was found that propagation of spatially downscaled satellite rainfall in the hydrologic model increased simulation uncertainty in streamflow as rainfall grid scales became smaller than 0.25°. The streamflow simulation uncertainty for satellite downscaling was found to be very similar to that for ground validation Next Generation Weather Radar (NEXRAD) downscaling at any given scale, indicating that the effectiveness of the spatial downscaling scheme is not influenced by rainfall data type. Closer inspection at the subbasin level revealed that the limitation of the selected spatial downscaling scheme to preserve the mean rainfall intensity for irregularly sized drainage units was responsible for the increase in simulation uncertainty as scales became smaller. Although the findings should not be construed as a generalization for spatial downscaling schemes, there is a need for more rigorous hydrometeorological assessment of downscaled satellite rainfall data prior to institutionalizing its use for real-time streamflow simulation over ungauged basins.

scholarly journals Accuracy Analysis of IMERG Satellite Rainfall Data and Its Application in Long-term Runoff Simulation

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2177
Author(s):  
Chongxun Mo ◽  
Mingshan Zhang ◽  
Yuli Ruan ◽  
Junkai Qin ◽  
Yafang Wang ◽  
...  
Keyword(s):  
Swat Model ◽  
Probability Of Detection ◽  
Rainfall Data ◽  
Karst Area ◽  
Efficiency Coefficient ◽  
Accuracy Analysis ◽  
Runoff Simulation ◽  
Satellite Rainfall ◽  
Simulation Results

Frequent flood disasters have caused serious damage to karst areas with insufficient measured rainfall data, and the analysis of the applicability of satellite rainfall data in runoff simulation is helpful to the local water management. Therefore, the purpose of this study is to analyze the accuracy of IMERG satellite rainfall data and apply it to long-term runoff simulations in a karst area—the Xiajia River basin, China. First, R (correlation coefficient) and POD (probability of detection) are applied to analyze the accuracy of the IMERG data, and the SWAT model is used for runoff simulation. The results show that the accuracy of the original IMERG data is poor (R range from 0.412 to 0.884 and POD range from 47.33 to 100), and the simulation results are “Unsatisfactory” (NSE (Nash-Sutcliffe efficiency coefficient) ranged from 0.17 to 0.32 and RSR (root mean square standard deviation ratio) ranged from 0.81 to 0.92). Therefore, the GDA correction method is used to correct the original IMERG data, and then the accuracy analysis and runoff simulation are carried out. The results show that the accuracy of the corrected IMERG data is better than that of the original data (R range from 0.886 to 0.987 and POD range from 94.08 to 100), and the simulation results of the corrected IMERG data are “Satisfactory” (NSE is over 0.55 and RSR is approximately 0.65). Therefore, the corrected data have a certain applicability in long-term continuous runoff simulations.

scholarly journals Large-Scale Influences on Atmospheric River–Induced Extreme Precipitation Events along the Coast of Washington State

2020 ◽  
Vol 21 (9) ◽  
pp. 2139-2156
Author(s):  
Allison B. Marquardt Collow ◽  
Haiden Mersiovsky ◽  
Michael G. Bosilovich
Keyword(s):  
Water Vapor ◽  
Extreme Precipitation ◽  
Large Scale ◽  
Washington State ◽  
Vapor Transport ◽  
Extreme Precipitation Event ◽  
Water Vapor Transport ◽  
Precipitation Event ◽  
Extreme Precipitation Events ◽  
Precipitation Events

AbstractTransient, narrow plumes of strong water vapor transport, referred to as atmospheric rivers (ARs), are responsible for much of the precipitation along the West Coast of the United States. The most intense precipitation events are almost always induced by an AR on the coast of Oregon and Washington and can result in detrimental impacts on society due to mudslides and flooding. To accurately predict AR events on numerical weather prediction, subseasonal, and seasonal time scales, it is important to understand the large-scale impacts on extreme AR events. Here, characteristics of ARs that result in an extreme precipitation event are compared to typical ARs on the coast of Washington State. In addition to more intense water vapor transport, notable differences in the synoptic forcing are present during extreme precipitation events that are not present during typical AR events. Subseasonal and seasonal teleconnection patterns are known to influence the weather in the Pacific Northwest and are investigated here. The Madden–Julian oscillation (MJO) plays a role in determining the strength of precipitation associated with an AR on the Washington coast. Phase 5 of the MJO (convection centered over the Maritime Continent) is the most common phase during an extreme precipitation event, while phase 2 (convection over the Indian Ocean) discourages an extreme event from occurring. Interactions between El Niño–Southern Oscillation (ENSO) and the propagation speed of the MJO result in extreme events during phase 1 of the MJO and El Niño but phase 8 during neutral ESNO conditions.

scholarly journals Temporal analyses of Salmonellae in a headwater spring ecosystem reveals the effects of precipitation and runoff events

2008 ◽  
Vol 7 (1) ◽  
pp. 115-121 ◽  
Author(s):  
James P. Gaertner ◽  
Tiffany Garres ◽  
Jesse C. Becker ◽  
Maria L. Jimenez ◽  
Michael R. J. Forstner ◽  
...  
Keyword(s):  
Molecular Techniques ◽  
Precipitation Event ◽  
Rainfall Events ◽  
Before And After ◽  
San Marcos ◽  
Polymerase Chain ◽  
Spring Lake ◽  
Events Detection ◽  
Precipitation Events

Sediments and water from the spring and slough arm of Spring Lake, the pristine headwaters of the San Marcos River, Texas, were analyzed for Salmonellae by culture and molecular techniques before and after three major precipitation events, each with intermediate dry periods. Polymerase chain reaction (PCR)-assisted analyses of enrichment cultures detected Salmonellae in samples after all three precipitation events, but failed to detect them immediately prior to the rainfall events. Detection among individual locations differed with respect to the precipitation event analyzed, and strains isolated were highly variable with respect to serovars. These results demonstrate that rainwater associated effects, most likely surface runoff, provide an avenue for short-term pollution of aquatic systems with Salmonellae that do not, however, appear to establish for the long-term in water nor sediments.

Relationships between Large-Scale Regime Transitions and Major Cool-Season Precipitation Events in the Northeastern United States

2010 ◽  
Vol 138 (9) ◽  
pp. 3454-3473 ◽  
Author(s):  
Heather M. Archambault ◽  
Daniel Keyser ◽  
Lance F. Bosart
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
North Atlantic ◽  
Large Scale ◽  
Precipitation Event ◽  
Composite Analysis ◽  
Cool Season ◽  
Regime Transitions ◽  
Precipitation Events

Abstract This observational study investigates statistical and synoptic–dynamic relationships between regime transitions, defined as a North Atlantic Oscillation (NAO) or Pacific–North American pattern (PNA) index change from at least a 1 standard deviation anomaly to at least a 1 standard deviation anomaly of opposite sign within 7 days, and cool-season (November–April) northeastern U.S. (NE) precipitation. A statistical analysis is performed of daily cool-season NE precipitation during all NAO and PNA transitions for 1948–2003, and a composite analysis and case study of a major cool-season NE precipitation event occurring during a positive-to-negative NAO transition are conducted. Datasets used are the 0.25° NCEP Unified Precipitation Dataset, the 2.5° NCEP–NCAR reanalysis, and the 1.125° 40-yr ECMWF Re-Analysis (ERA-40). Results of the statistical analysis suggest that cool-season NE precipitation tends to be enhanced during positive-to-negative NAO and negative-to-positive PNA transitions, and suppressed during negative-to-positive NAO and positive-to-negative PNA transitions. Of the four types of regime transitions, only the positive-to-negative NAO transition is associated with substantially more frequent major cool-season NE precipitation events compared to climatology. Results of the composite analysis and case study indicate that a surface cyclone and cyclonic wave breaking associated with the major NE precipitation event can help produce a high-latitude blocking pattern over the North Atlantic characteristic of a negative NAO pattern via thermal advection, potential vorticity transport, and diabatic processes.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

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