scholarly journals A Comparison of Various Correction and Blending Techniques for Creating an Improved Satellite-Gauge Rainfall Dataset over Australia

2022 ◽  
Vol 14 (2) ◽  
pp. 261
Author(s):  
Zhi-Weng Chua ◽  
Yuriy Kuleshov ◽  
Andrew B. Watkins ◽  
Suelynn Choy ◽  
Chayn Sun
Keyword(s):  
High Performance ◽  
Error Variance ◽  
Rain Gauge ◽  
Rainfall Analysis ◽  
Rain Gauges ◽  
The World ◽  
Potential Applicability ◽  
Complementary Nature ◽  
Improved Accuracy ◽  
Specific Correction

Satellites offer a way of estimating rainfall away from rain gauges which can be utilised to overcome the limitations imposed by gauge density on traditional rain gauge analyses. In this study, Australian station data along with the Japan Aerospace Exploration Agency’s (JAXA) Global Satellite Mapping of Precipitation (GSMaP) and the Bureau of Meteorology’s (BOM) Australian Gridded Climate Dataset (AGCD) rainfall analysis are combined to develop an improved satellite-gauge rainfall analysis over Australia that uses the strengths of the respective data sources. We investigated a variety of correction and blending methods with the aim of identifying the optimal blended dataset. The correction methods investigated were linear corrections to totals and anomalies, in addition to quantile-to-quantile matching. The blending methods tested used weights based on the error variance to MSWEP (Multi-Source Weighted Ensemble Product), distance to the closest gauge, and the error from a triple collocation analysis to ERA5 and Soil Moisture to Rain. A trade-off between away-from- and at-station performances was found, meaning there was a complementary nature between specific correction and blending methods. The most high-performance dataset was one corrected linearly to totals and subsequently blended to AGCD using an inverse error variance technique. This dataset demonstrated improved accuracy over its previous version, largely rectifying erroneous patches of excessive rainfall. Its modular use of individual datasets leads to potential applicability in other regions of the world.

scholarly journals Assessment of Snowfall Accumulation from Satellite and Reanalysis Products Using SNOTEL Observations in Alaska

2021 ◽  
Vol 13 (15) ◽  
pp. 2922
Author(s):  
Yang Song ◽  
Patrick D. Broxton ◽  
Mohammad Reza Ehsani ◽  
Ali Behrangi
Keyword(s):  
Snow Water Equivalent ◽  
Stage Iv ◽  
Microwave Remote Sensing ◽  
Rain Gauge ◽  
Snow Accumulation ◽  
Correction Factors ◽  
Rainfall Analysis ◽  
Rain Gauges ◽  
Snow Properties ◽  
Precipitation Estimates

The combination of snowfall, snow water equivalent (SWE), and precipitation rate measurements from 39 snow telemetry (SNOTEL) sites in Alaska were used to assess the performance of various precipitation products from satellites, reanalysis, and rain gauges. Observation of precipitation from two water years (2018–2019) of a high-resolution radar/rain gauge data (Stage IV) product was also utilized to give insights into the scaling differences between various products. The outcomes were used to assess two popular methods for rain gauge undercatch correction. It was found that SWE and precipitation measurements at SNOTELs, as well as precipitation estimates based on Stage IV data, are generally consistent and can provide a range within which other products can be assessed. The time-series of snowfall and SWE accumulation suggests that most of the products can capture snowfall events; however, differences exist in their accumulation. Reanalysis products tended to overestimate snow accumulation in the study area, while the current combined passive microwave remote sensing products (i.e., IMERG-HQ) underestimate snowfall accumulation. We found that correction factors applied to rain gauges are effective for improving their undercatch, especially for snowfall. However, no improvement in correlation is seen when correction factors are applied, and rainfall is still estimated better than snowfall. Even though IMERG-HQ has less skill for capturing snowfall than rainfall, analysis using Taylor plots showed that the combined microwave product does have skill for capturing the geographical distribution of snowfall and precipitation accumulation; therefore, bias adjustment might lead to reasonable precipitation estimates. This study demonstrates that other snow properties (e.g., SWE accumulation at the SNOTEL sites) can complement precipitation data to estimate snowfall. In the future, gridded SWE and snow depth data from GlobSnow and Sentinel-1 can be used to assess snowfall and its distribution over broader regions.

scholarly journals Subpixel-Scale Rainfall Variability and the Effects on Separation of Radar and Gauge Rainfall Errors

2007 ◽  
Vol 8 (6) ◽  
pp. 1348-1363 ◽  
Author(s):  
Yu Zhang ◽  
Thomas Adams ◽  
James V. Bonta
Keyword(s):  
Spatial Correlation ◽  
Rainfall Variability ◽  
Domain Size ◽  
Error Variance ◽  
Rainfall Analysis ◽  
Rain Gauges ◽  
Size Number ◽  
Proportional Contribution ◽  
Error Terms ◽  
Areal Rainfall

Abstract This paper presents an extended error variance separation method (EEVS) that allows explicit partitioning of the variance of the errors in gauge- and radar-based representations of areal rainfall. The implementation of EEVS demonstrated in this study combines a kriging scheme for estimating areal rainfall from gauges with a sampling method for determining the correlation between the gauge- and radar-related errors. On the basis of this framework, this study examines scale- and pixel-dependent impacts of subpixel-scale rainfall variability on the perceived partitioning of error variance for four conterminous Hydrologic Rainfall Analysis Project (HRAP) pixels in central Ohio with data from Next-Generation Weather Radar (NEXRAD) stage III product and from 11 collocated rain gauges as input. Application of EEVS for 1998–2001 yields proportional contribution of two error terms for July and October for each HRAP pixel and for two fictitious domains containing the gauges (4 and 8 km in size). The results illustrate the importance of considering subpixel variation of spatial correlation and how it varies with the size of domain size, number of gauges, and the subpixel locations of gauges. Further comparisons of error variance separation (EVS) and EEVS across pixels results suggest that accounting for structured variations in the spatial correlation under 8 km might be necessary for more accurate delineation of domain-dependent partitioning of error variance, and especially so for the summer months.

scholarly journals Assessment of Snowfall Accumulation from Satellite and Reanalysis Products Using SNOTEL Observations in Alaska

2021 ◽  
Author(s):  
Yang Song ◽  
Patrick Broxton ◽  
Mohammad Reza Ehsani ◽  
Ali Behrangi
Keyword(s):  
Snow Water Equivalent ◽  
Stage Iv ◽  
Microwave Remote Sensing ◽  
Rain Gauge ◽  
Snow Accumulation ◽  
Rainfall Analysis ◽  
Rain Gauges ◽  
Snow Properties ◽  
Precipitation Estimates ◽  
High Resolution Radar

The combination of snowfall, snow water equivalent (SWE), and precipitation rate measurements from 39 Snow Telemetry (SNOTEL) sites in Alaska are used to assess the performance of various precipitation products from satellites, reanalysis, and rain gauges. Observation of precipitation from two water years (2018-2019) of the high resolution radar/rain gauge data (Stage IV) product was also utilized to add insights into scaling differences between various products. The outcomes were also used to assess two popular methods for rain gauge undercatch correction. It was found that SWE and precipitation measurements at SNOTELs, as well as precipitation estimates based on Stage IV data, are generally consistent and can provide a range in which other products can be assessed. Time-series of snowfall and SWE accumulation suggests that most of the products can capture snowfall events; however, differences exist in their accumulation. Reanalysis products tend to overestimate snow accumulation in the study area, while current combined passive microwave remote sensing products (i.e., IMERG-HQ) underestimate snowfall accumulation. We found that corrections factors applied to rain gauges are effective in improving their undercatch, especially for snowfall. However, no improvement in correlation is seen when correction factors are applied, and rainfall is still estimated better than snowfall. Even though IMERG-HQ has less skill in capturing snowfall than rainfall, analysis using Taylor plots showed that the combined microwave product does have skill in capturing the geographical distribution of snowfall and precipitation accumulation, so bias adjustment might lead to reasonable precipitation estimates. This study demonstrates that other snow properties (e.g., SWE accumulation at the SNOTEL sites) can complement precipitation data to estimate snowfall. In the future, gridded SWE and snow depth data from GlobSnow and Sentinel-1 can be used to assess snowfall and its distribution over broader regions.

scholarly journals Identification of the Optimum Rain Gauge Network Density for Hydrological Modelling Based on Radar Rainfall Analysis

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1906
Author(s):  
Yeboah Gyasi-Agyei
Keyword(s):  
Scaling Laws ◽  
Rain Gauge ◽  
Hydrological Modelling ◽  
Network Density ◽  
Sampled Data ◽  
Radar Rainfall ◽  
Rainfall Analysis ◽  
Rain Gauges ◽  
Performance Statistics ◽  
Rain Gauge Network

Rain gauges continue to be sources of rainfall data despite progress made in precipitation measurements using radar and satellite technology. There has been some work done on assessing the optimum rain gauge network density required for hydrological modelling, but without consensus. This paper contributes to the identification of the optimum rain gauge network density, using scaling laws and bias-corrected 1 km × 1 km grid radar rainfall records, covering an area of 28,371 km2 that hosts 315 rain gauges in south-east Queensland, Australia. Varying numbers of radar pixels (rain gauges) were repeatedly sampled using a unique stratified sampling technique. For each set of rainfall sampled data, a two-dimensional correlogram was developed from the normal scores obtained through quantile-quantile transformation for ordinary kriging which is a stochastic interpolation. Leave-one-out cross validation was carried out, and the simulated quantiles were evaluated using the performance statistics of root-mean-square-error and mean-absolute-bias, as well as their rates of change. A break in the scaling of the plots of these performance statistics against the number of rain gauges was used to infer the optimum rain gauge network density. The optimum rain gauge network density varied from 14 km2/gauge to 38 km2/gauge, with an average of 25 km2/gauge.

The Prediction of Rainfall and the Direction of Rainfall by a Narrow Area Radar Rain Gauge

1993 ◽  
Vol 28 (11-12) ◽  
pp. 79-85
Author(s):  
Shinichi Kondo
Keyword(s):  
Small Area ◽  
Arrival Time ◽  
Rain Gauge ◽  
Rain Gauges ◽  
Sewage Plant ◽  
Future Prediction ◽  
Near Future ◽  
Narrow Area

Narrow area radar rain gauges are currently used for measuring rainfall. These radar gauges can measure rainfall accurately in a small area. In sewage plants it is important to predict stormwater. To calculate predicted stormwater the results of rainfall and a prediction of the near future are necessary. Recently urbanization has made the arrival time of flooding to the sewage plant much shorter. This paper deals with system technologies for the near future prediction of radar rain gauge rainfall. The method of prediction of rainfall, calculation of results and other considerations are described.

Sulphonamide: Distribution, Toxicology, Environmental Characteristics, and Analysis - A Review

2020 ◽  
Vol 16 ◽  
Author(s):  
Kirubanandam Grace Pavithra ◽  
Vasudevan Jaikumar ◽  
Ponnusamy Senthil Kumar ◽  
PanneerSelvam SundarRajan
Keyword(s):  
Aqueous Solution ◽  
High Performance Liquid Chromatography ◽  
Capillary Electrophoresis ◽  
Liquid Chromatography ◽  
High Performance ◽  
Uv Spectroscopy ◽  
Relevant Information ◽  
Fluorometric Determination ◽  
Distinctive Features ◽  
The World

Background: Many antibiotics were widely used as medication based on their distinctive features. Among them, sulphonamides were commonly used, however their recalcitrant nature makes them difficult to dispose. Hence, their interaction with environment and analytic technique requires considerable attention globally. Objective: Therefore, this review aimed to provide detailed discussion about environmental as well as human health behaviour and analytic techniques corresponding to sulphonamides. Methods: Various results and discussion were extracted from technical journals and books published by different researchers from all over the world. The cited bibliographic references were intentionally investigated in order to extract relevant information related to proposed work. Results: In this review, the determination techniques such as UV-spectroscopy, Enthalpimetry, Immunosensor, Chromatography, Chemiluminescence, Photoinduced fluorometric determination, Capillary electrophoresis for sulphonamide determination were discussed in detail. Among them, High performance liquid chromatography (HPLC) and UV-spectroscopy was effective and extensively used for screening sulphonamide. Conclusion: Knowing the quantification and behaviour of sulphonamide in aqueous solution is mandatory to opt the suitable wastewater treatment required. Hence, choosing appropriate high precision and feasible screening techniques is necessary, which can be attained with this review.

scholarly journals A study on the numerical modelling of UHPFRC-strengthened members

2018 ◽  
Vol 199 ◽  
pp. 09001
Author(s):  
Renaud Franssen ◽  
Serhan Guner ◽  
Luc Courard ◽  
Boyan Mihaylov
Keyword(s):  
Numerical Modelling ◽  
High Performance ◽  
Concrete Structures ◽  
Concrete Members ◽  
High Durability ◽  
Tension Tests ◽  
The World ◽  
Aging Infrastructure ◽  
New Generation ◽  
Modelling Approach

The maintenance of large aging infrastructure across the world creates serious technical, environmental, and economic challenges. Ultra-high performance fibre-reinforced concretes (UHPFRC) are a new generation of materials with outstanding mechanical properties as well as very high durability due to their extremely low permeability. These properties open new horizons for the sustainable rehabilitation of aging concrete structures. Since UHPFRC is a young and evolving material, codes are still either lacking or incomplete, with recent design provisions proposed in France, Switzerland, Japan, and Australia. However, engineers and public agencies around the world need resources to study, model, and rehabilitate structures using UHPFRC. As an effort to contribute to the efficient use of this promising material, this paper presents a new numerical modelling approach for UHPFRC-strengthened concrete members. The approach is based on the Diverse Embedment Model within the global framework of the Disturbed Stress Field Model, a smeared rotating-crack formulation for 2D modelling of reinforced concrete structures. This study presents an adapted version of the DEM in order to capture the behaviour of UHPFRC by using a small number of input parameters. The model is validated with tension tests from the literature and is then used to model UHPFRC-strengthened elements. The paper will discuss the formulation of the model and will provide validation studies with various tests of beams, columns and walls from the literature. These studies will demonstrate the effectiveness of the proposed modelling approach.

Evaluation of Global Forecast System (GFS) Medium-Range Precipitation Forecasts in the Nile River Basin

2021 ◽  
Author(s):  
Haowen Yue ◽  
Mekonnen Gebremichael ◽  
Vahid Nourani
Keyword(s):  
Temporal Dynamics ◽  
Disease Outbreaks ◽  
Rain Gauge ◽  
Global Forecast System ◽  
Forecast System ◽  
Forecast Performance ◽  
Weather Forecasts ◽  
Rain Gauges ◽  
Basin Scale ◽  
Medium Range

Abstract Reliable weather forecasts are valuable in a number of applications, such as, agriculture, hydropower, and weather-related disease outbreaks. Global weather forecasts are widely used, but detailed evaluation over specific regions is paramount for users and operational centers to enhance the usability of forecasts and improve their accuracy. This study presents evaluation of the Global Forecast System (GFS) medium-range (1 day – 15 day) precipitation forecasts in the nine sub-basins of the Nile basin using NASA’s Integrated Multi-satellitE Retrievals (IMERG) “Final Run” satellite-gauge merged rainfall observations. The GFS products are available at a temporal resolution of 3-6 hours, spatial resolution of 0.25°, and its version-15 products are available since 12 June 2019. GFS forecasts are evaluated at a temporal scale of 1-15 days, spatial scale of 0.25° to all the way to the sub-basin scale, and for a period of one year (15 June 2019 – 15 June 2020). The results show that performance of the 1-day lead daily basin-averaged GFS forecast performance, as measured through the modified Kling-Gupta Efficiency (KGE), is poor (0 < KGE < 0.5) for most of the sub-basins. The factors contributing to the low performance are: (1) large overestimation bias in watersheds located in wet climate regimes in the northern hemispheres (Millennium watershed, Upper Atbara & Setit watershed, and Khashm El Gibra watershed), and (2) lower ability in capturing the temporal dynamics of watershed-averaged rainfall that have smaller watershed areas (Roseires at 14,110 sq. km and Sennar at 13,895 sq. km). GFS has better bias for watersheds located in the dry parts of the northern hemisphere or wet parts of the southern hemisphere, and better ability in capturing the temporal dynamics of watershed-average rainfall for large watershed areas. IMERG Early has better bias than GFS forecast for the Millennium watershed but still comparable and worse bias for the Upper Atbara & Setit, and Khashm El Gibra watersheds. The variation in the performance of the IMERG Early could be partly explained by the number of rain gauges used in the reference IMERG Final product, as 16 rain gauges were used for the Millennium watershed but only one rain gauge over each Upper Atbara & Setit, and Khashm El Gibra watershed. A simple climatological bias-correction of IMERG Early reduces in the bias in IMERG Early over most watersheds, but not all watersheds. We recommend exploring methods to increase the performance of GFS forecasts, including post-processing techniques through the use of both near-real-time and research-version satellite rainfall products.

scholarly journals Fall panicum (Panicum dichotomiflorum) toxicosis in three juvenile goats

2018 ◽  
Vol 31 (1) ◽  
pp. 90-93
Author(s):  
Sarah J. Sillman ◽  
Stephen T. Lee ◽  
Jeff Claborn ◽  
Jennifer Boruch ◽  
Seth P. Harris
Keyword(s):  
Bile Ducts ◽  
High Performance ◽  
Small Ruminants ◽  
Clinical Findings ◽  
Steroidal Saponin ◽  
Renal Tubules ◽  
Liquid Chromatography Mass Spectrometry ◽  
Steroidal Saponins ◽  
The World ◽  
Panicum Dichotomiflorum

Consumption of certain grasses belonging to the genus Panicum has been found to cause hepatogenous photosensitization and crystal-associated cholangiohepatopathy in small ruminants, and liver disease in horses, in many areas of the world. We describe herein the clinical findings, microscopic lesions, and steroidal saponin analysis of Panicum dichotomiflorum associated with fatal toxicosis in 3 juvenile goats in Nebraska. The disease presentation in our case was fulminant, with anorexia, marked icterus, and death for all affected animals in less than a week. Photosensitization was not observed. The microscopic lesions consisted of severe crystal-associated cholangiohepatopathy and nephropathy, with aggregates of clear or refractile and birefringent, acicular crystals present within bile ducts, macrophages, hepatocytes, and renal tubules. High-performance liquid chromatography–mass spectrometry of the grass samples demonstrated that dichotomin was the major steroidal saponin present (0.89 µg/mg); protodioscin was also present (0.059 µg/mg). The findings were consistent with ingestion of steroidal saponins, and P. dichotomiflorum was identified as the predominant forage available.

scholarly journals TOTAL QUALITY MANAGEMENT: PARADIGMA BARU MANAGEMEN PERGURUAN TINGGI DALAM MENGHADAPI PERSAINGAN KUALITAS PENDIDIKAN

2017 ◽  
Vol 3 (1) ◽  
pp. 67
Author(s):  
Wariyanti Wariyanti
Keyword(s):  
Total Quality Management ◽  
High Performance ◽  
Educational Process ◽  
Public Institution ◽  
Human Beings ◽  
Total Quality ◽  
National Education ◽  
The World ◽  
Fear Of God ◽  
Agent Of Change

<p>College is one of the means to build community. Universities can also be regarded as the agent of change in society and even the world. Humans were expected today are capable of developing their potential throughout. Overview whole human beings has been defined in the law No. 20 of 2003 on the System Pendidian National Article 3 which states that the National Education aims at developing students' potentials in order to become a man of faith and fear of God Almighty, noble, healthy, knowledgeable, skilled, creative, independent, and become citizens of a democratic and accountable. Based on these conditions, a University is a public institution undertaking the community to help to create students who have the expected quality. With the demands of current conditions it is necessary seoramg leaders and members who have high performance in managing and running the educational process. While universities are expected are universities which have members who are always learning to achieve a change for the better in serving the community.</p>

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