scholarly journals A (small) step towards standardisation in rainfall simulation experiments

2020 ◽  
Author(s):  
Jorge Isidoro ◽  
Ian Pattison ◽  
Thomas Iserloh ◽  
João de Lima ◽  
Daniel Green ◽  
...  
Keyword(s):  
Measurement Methods ◽  
Transport Processes ◽  
Rainfall Event ◽  
Rainfall Simulation ◽  
Small Step ◽  
Simulation Experiments ◽  
Rainfall Simulator ◽  
Research Areas ◽  
Artificial Rainfall ◽  
Wide Range

<p>Rainfall simulation is widely used within hydrological and geomorphological sciences and is particularly important in the study of rainfall-runoff, erosion and pollutant transport processes. Rainfall simulators have been applied within laboratory- and field-based studies and have the advantages of enabling controlled and reproducible rainfall event characteristics in relation to rainfall intensity, duration, and drop spectra. The flexibility and advantages of using rainfall simulators to study a wide range of research objectives has resulted in significant diversity in the type, sizing, form, operation and methodologies of rainfall simulators, and an extensive review of rainfall simulator research has led to more than 250 different rainfall simulator setups being identified in the literature. Rainfall simulators come in all different shapes and sizes!</p><p>The adaptability of rainfall simulators to study a wide range of research areas of varying scale ultimately results in several issues when comparing results and outputs obtained from different simulator setups. In fact, comparisons between studies can be very difficult, if not impossible, as the different measurement methods, artificial rainfall event characteristics and test conditions result in considerable difficulties when benchmarking results and findings obtained from rainfall simulation experiments. Thus, the scientific community should establish set methodological procedures to allow comparisons between results obtained from different rainfall simulator setups. Harmonization of basic procedures in rainfall simulator based studies in the fields of hydrological and geomorphological sciences would ensure that results between different rainfall simulator studies are comparable, standardised and regulated. The first step in this process involves standardising rainfall simulators design characteristics, whereas further steps should focus on measurement methods and metrics so results can be compared.</p><p>This paper aims to bring together current understanding on the use of rainfall simulators within hydrological and geomorphological research, and provide a platform to discuss and enhance understanding of the requirements on the standardisation of rainfall simulator based experimental research. This paper also aims to establish an international research community focused on advancing standardisation in rainfall simulation based at different research facilities and institutes, and will kick-start discussions leading up to a future international symposium dealing with these issues (date TBC). Everyone is invited to join this (small) step towards standardisation in rainfall simulation!</p>

Moving towards harmonisation in rainfall simulation

2021 ◽  
Author(s):  
Thomas Iserloh ◽  
Jorge M. G. P. Isidoro ◽  
João L. M. P. de Lima ◽  
Miriam Marzen ◽  
M. Isabel P. de Lima ◽  
...  
Keyword(s):  
Scientific Community ◽  
Spatial Scales ◽  
Measurement Methods ◽  
Transport Processes ◽  
Rainfall Simulation ◽  
Simulation Experiments ◽  
Rainfall Simulator ◽  
Specific Research ◽  
Artificial Rainfall ◽  
Methodological Procedures

<p>Rainfall simulation experiments are widely used in soil science, geomorphology and hydrology research and teaching. Such experimental setups are particularly important in the study of rainfall-runoff, erosion and pollutant transport processes. Rainfall simulators have been applied within laboratory- and field-based studies and have the advantage of enabling controlled and reproducible rainfall events of varying intensity, duration and drop spectra. The flexibility and adaptability of rainfall simulators to examine diverse research applications of varying temporal and spatial scales means that hundreds of tailor-made rainfall simulator setups can be identified across the literature. Although it is beneficial for researchers to adapt their experimental designs to suit their specific research objectives, the diversity in the type, sizing, form, operation and methodologies of rainfall simulators ultimately results in complications when comparing results and outputs obtained between studies.</p><p>Currently, comparisons between studies can be very difficult, if not impossible, as the different measurement methods, artificial rainfall event characteristics and test conditions result in considerable difficulties when benchmarking results and findings obtained from rainfall simulation experiments. We recommend that the scientific community should establish a set of methodological procedures aimed at harmonising basic procedures in rainfall simulator-based studies in the fields of hydrological and geomorphological sciences. This would ensure that results obtained from different rainfall simulator studies and setups are harmonised, regulated and comparable. On the one hand, this process involves harmonising rainfall simulators design characteristics, whereas further steps should focus on measurement methods and metrics so results can be more readily compared.</p><p>This presentation highlights the inherit problems in benchmarking and comparing studies at present due to large variations in the way that researchers and institutions assess and quantify rainfall simulator performance and present results. Some degree of ‘standardisation’ of rainfall simulator approaches is needed. However, standardising approaches used within rainfall simulation does not allow researchers to adapt their experimental setups to suit their specific research needs, which is one of the key benefits of using rainfall simulators. Instead, ‘harmonisation’ (i.e. ensuring that the scientific community develop a set of regulated and comparable methodological procedures and best practices for use in rainfall simulator studies whilst still allowing some degree of adaptability for specific research practices) is required. Here we present a series of harmonisation procedures, which should be developed to ensure that rainfall simulators are designed and constructed to allow for harmonisation, as well as suggesting a series of steps towards harmonising the methods and metrics used to quantify and compare experimental results.</p><p>With these objectives in mind, we aim to stimulate the discussion and enhance understanding of the difficulties and requirements of rainfall simulator based experimental research, namely by creating a platform that embraces and consults the International research community across multiple research facilities and institutes. This presentation will kick-start discussions (via web seminar sessions beginning in Summer 2021) leading up to a future international symposium addressing and acting upon these issues and disseminating the findings of this consultation period (Spring/Summer 2022 in Coimbra, Portugal). Everyone is invited to join this step towards harmonisation in rainfall simulation.</p>

scholarly journals Design, Operation and Construction of a Large Rainfall Simulator for the Field Study on Acidic Barren Slope

2018 ◽  
Vol 4 (8) ◽  
pp. 1851 ◽  
Author(s):  
Siti Fazlina MD Isa ◽  
A T S Azhar ◽  
M Aziman
Keyword(s):  
Large Scale ◽  
Soft Soil ◽  
Test System ◽  
Rainfall Simulation ◽  
Rainfall Simulator ◽  
R And D ◽  
Subsequent Test ◽  
Pumping System ◽  
Artificial Rainfall ◽  
Set Up

The utilization of rainfall simulators has turned out to be more far reaching with the automated instrumentation and control systems. This paper portrays a rainfall simulator designed for analysis of erosion on steep (2.5H: 1V). A rainfall simulator designed to perform experiments in slope is introduced. The large scale of the apparatus allows the researcher to work in remote areas and on steep slopes. This simulator was designed to be effortlessly set up and kept up as well as able and additionally ready to create a variety of rainfall regimes. The nozzle performance tests and lateral spacing tests were performed at Research Center for Soft Soil (RECESS), which is another Research and Development (R and D) activity by Universiti Tun Hussein Onn Malaysia. This test system is the standard for research involving simulated rainfall. The rainfall simulator is a pressurized nozzle type simulator. It discharges uniform rainfall on a square plot 6 m wide by 6 m (19.685 ft) long. The fundamental parts of a sprinkler rainfall simulator are a nozzle, a structure in which installs the nozzle, and the connections with the water supply and the pumping system. The structure of the test system was manufactured created with four fixed hollow rectangular galvanised on which a header with 25 nozzles attached to it. The nozzles are spaced 1 m apart. Flow meters control the inflow of water from the storage tank, ensuring each nozzle has a similar release rate, regardless of the introduction of the test system. The tank that was utilized has the 200 gallons of water which is 757.08 Lit and the full with water in tank can run the artificial rainfall simulation roughly around 50 to 60 minutes. The support system is collapsible, easy to set up and maintain. The subsequent test system is conservative (under RM9,000 to build), made with industrially accessible parts, simple to set-up and maintain and highly accurate.

scholarly journals Rainfall simulation experiments in the Southwestern USA using the Walnut Gulch Rainfall Simulator

2017 ◽  
Author(s):  
Viktor Polyakov ◽  
Jeffry Stone ◽  
Chandra Holifield Collins ◽  
Mark A. Nearing ◽  
Ginger Paige ◽  
...  
Keyword(s):  
Ground Cover ◽  
Rainfall Simulation ◽  
Supplementary Information ◽  
Simulation Experiments ◽  
Data Set ◽  
Rainfall Simulator ◽  
Ecological Sites ◽  
Erosion Rates ◽  
Southwestern Usa ◽  
Walnut Gulch

Abstract. The dataset contains hydrological, erosion, vegetation, ground cover, and other supplementary information from 272 rainfall simulation experiments conducted on 23 semi-arid rangeland locations in Arizona and Nevada between 2002 and 2013. On 30 % of the plots simulations were conducted up to five times during the decade of study. The rainfall was generated using the Walnut Gulch Rainfall Simulator on 2 m by 6 m plots. Simulation sites included brush and grassland areas with various degree of disturbance by grazing, wildfire, or brush removal. This dataset advances our understanding of basic hydrological and biological processes that drive soil erosion on arid rangelands. It can be used to quantify runoff, infiltration, and erosion rates on a variety of ecological sites in the Southwestern USA. Inclusion of wildfire and brush treatment locations combined with long term observations makes it important for studying vegetation recovery, ecological transitions, and effect of management. It is also a valuable resource for erosion model parameterization and validation. The data set available from the National Agricultural Library at https://data.nal.usda.gov/search/type/dataset (https://doi.org/doi:10.15482/USDA.ADC/1358583).

scholarly journals Rainfall simulation experiments in the southwestern USA using the Walnut Gulch Rainfall Simulator

2018 ◽  
Vol 10 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Viktor Polyakov ◽  
Jeffry Stone ◽  
Chandra Holifield Collins ◽  
Mark A. Nearing ◽  
Ginger Paige ◽  
...  
Keyword(s):  
Ground Cover ◽  
Rainfall Simulation ◽  
Supplementary Information ◽  
Simulation Experiments ◽  
Rainfall Simulator ◽  
Ecological Sites ◽  
Erosion Rates ◽  
Model Parameterization ◽  
Southwestern Usa ◽  
Walnut Gulch

Abstract. This dataset contains hydrological, erosion, vegetation, ground cover, and other supplementary information from 272 rainfall simulation experiments conducted on 23 semiarid rangeland locations in Arizona and Nevada between 2002 and 2013. On 30 % of the plots, simulations were conducted up to five times during the decade of study. The rainfall was generated using the Walnut Gulch Rainfall Simulator on 2 m by 6 m plots. Simulation sites included brush and grassland areas with various degrees of disturbance by grazing, wildfire, or brush removal. This dataset advances our understanding of basic hydrological and biological processes that drive soil erosion on arid rangelands. It can be used to estimate runoff, infiltration, and erosion rates at a variety of ecological sites in the Southwestern USA. The inclusion of wildfire and brush treatment locations combined with long-term observations makes it important for studying vegetation recovery, ecological transitions, and the effect of management. It is also a valuable resource for erosion model parameterization and validation. The dataset is available from the National Agricultural Library at https://data.nal.usda.gov/search/type/dataset (DOI: https://doi.org/10.15482/USDA.ADC/1358583).

Rainfall simulation experiments in vineyards comparing two different plot scales

2021 ◽  
Author(s):  
Martin Neumann ◽  
Petr Kavka ◽  
Jan Devátý ◽  
Luděk Strouhal ◽  
Adam Tejkl ◽  
...  
Keyword(s):  
High Water ◽  
Point Of View ◽  
Rainfall Simulation ◽  
Simulation Experiments ◽  
Rainfall Simulator ◽  
Erosion Processes ◽  
Landscape Water ◽  
The World ◽  
Grant Agency ◽  
Experimental Plots

<p>Vineyards are vulnerable to soill loss due to the several inherent factors highly discussed in the literature. A lot of research is being carried out on this topic and hundreds of experiments were conducted around the world in past decades. The use of rainfall simulators is very extensive with prominent results; however, the use of different scales is scarce in exact places but using different plot sizes. Small (1-4 m<sup>2</sup>) and big plots (>4 m<sup>2</sup>) can detect the initiation of specific processes such as surface runoff and initial of soill particle detachment. However, mechanisms such as connectivity, sedimentation or linear erosion differ among plot sizes. Also, the size, high water consumption and time-consuming of the big rainfall simulator makes its use something scarce. Therefore, the main goal of this research was to compare the big and small rainfall simulators and the obtained results considering the continuous development of various rainfall simulators on the CTU’s Department of Landscape Water Management (Prague, Czech Republic). The small rainfall simulator with 1x1 m plot and the big one covering two experimental plots of 8x1 m size were used next to each other in a conventional vineyard in the viticultural region of Moravia. The results showed different processes both of them key to understand from a holistic point of view the inititaion of soil erosion processes in vineyards.</p><p>This study has been supported by the Grant Agency of the Czech Technical University in Prague, grant No. SGS20/156/OHK1/3T/11 and the Project QK1910029.</p>

scholarly journals Spectral Broadening in a Continuously Pumped Singly Resonant Second-Harmonic Cavity

2021 ◽  
Vol 11 (15) ◽  
pp. 7122
Author(s):  
Simona Mosca ◽  
Tobias Hansson ◽  
Maria Parisi
Keyword(s):  
Continuous Wave ◽  
Frequency Comb ◽  
Second Harmonic ◽  
Input Power ◽  
Second Order ◽  
Optical Frequency ◽  
Frequency Combs ◽  
Research Areas ◽  
Mixed Regime ◽  
Wide Range

Optical frequency comb synthesizers with a wide spectral range are an essential tool for many research areas such as spectroscopy, precision metrology, optical communication, and sensing. Recent studies have demonstrated the direct generation of frequency combs, via second-order processes, that are centered on two different spectral regions separated by an octave. Here, we present the capability of optical quadratic frequency combs for broad-bandwidth spectral emission in unexplored regimes. We consider comb formation under phase-matched conditions in a continuous-wave pumped singly resonant second-harmonic cavity, with large intracavity power and control of the detuning over several cavity line widths. The spectral analysis reveals quite distinctive sidebands that arise far away from the pump, singularly or in a mixed regime together with narrowband frequency combs. Notably, by increasing the input power, the optical frequency lines evolve into widely spaced frequency clusters, and at maximum power, they appear in a wavelength range spanning up to 100 nm. The obtained results demonstrate the power of second-order nonlinearities for direct comb production within a wide range of pump wavelengths.

scholarly journals Straw mulch as a sustainable solution to decrease runoff and erosion in glyphosate-treated clementine plantations in Eastern Spain. An assessment using rainfall simulation experiments

CATENA ◽  
2019 ◽  
Vol 174 ◽  
pp. 95-103 ◽  
Author(s):  
S.D. Keesstra ◽  
J. Rodrigo-Comino ◽  
A. Novara ◽  
A. Giménez-Morera ◽  
M. Pulido ◽  
...  
Keyword(s):  
Rainfall Simulation ◽  
Simulation Experiments ◽  
Straw Mulch

scholarly journals Physical Transport Processes that Affect the Distribution of Oil in the Gulf of Mexico: Observations and Modeling

Oceanography ◽  
2021 ◽  
Vol 34 (1) ◽  
pp. 58-75
Author(s):  
Michel Boufadel ◽  
◽  
Annalisa Bracco ◽  
Eric Chassignet ◽  
Shuyi Chen ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Physical Environment ◽  
Large Scale ◽  
Transport Processes ◽  
Small Scale ◽  
Surface Mixed Layer ◽  
Physical Processes ◽  
Mixing Processes ◽  
Near Surface ◽  
Wide Range

Physical transport processes such as the circulation and mixing of waters largely determine the spatial distribution of materials in the ocean. They also establish the physical environment within which biogeochemical and other processes transform materials, including naturally occurring nutrients and human-made contaminants that may sustain or harm the region’s living resources. Thus, understanding and modeling the transport and distribution of materials provides a crucial substrate for determining the effects of biological, geological, and chemical processes. The wide range of scales in which these physical processes operate includes microscale droplets and bubbles; small-scale turbulence in buoyant plumes and the near-surface “mixed” layer; submesoscale fronts, convergent and divergent flows, and small eddies; larger mesoscale quasi-geostrophic eddies; and the overall large-scale circulation of the Gulf of Mexico and its interaction with the Atlantic Ocean and the Caribbean Sea; along with air-sea interaction on longer timescales. The circulation and mixing processes that operate near the Gulf of Mexico coasts, where most human activities occur, are strongly affected by wind- and river-induced currents and are further modified by the area’s complex topography. Gulf of Mexico physical processes are also characterized by strong linkages between coastal/shelf and deeper offshore waters that determine connectivity to the basin’s interior. This physical connectivity influences the transport of materials among different coastal areas within the Gulf of Mexico and can extend to adjacent basins. Major advances enabled by the Gulf of Mexico Research Initiative in the observation, understanding, and modeling of all of these aspects of the Gulf’s physical environment are summarized in this article, and key priorities for future work are also identified.

Plasma Diagnostics of Microflares observed by STIX and AIA

2021 ◽  
Author(s):  
Jonas Saqri ◽  
Astrid Veronig ◽  
Ewan Dickson ◽  
Säm Krucker ◽  
Andrea Francesco Battaglia ◽  
...  
Keyword(s):  
Solar Flares ◽  
Magnetic Energy ◽  
Emission Measure ◽  
Transport Processes ◽  
X Rays ◽  
Solar Dynamics Observatory ◽  
Energy Bands ◽  
Accurate Analysis ◽  
Great Opportunity ◽  
Wide Range

<p>Solar flares are generally thought to be the impulsive release of magnetic energy giving rise to a wide range of solar phenomena that influence the heliosphere and in some cases even conditions of earth. Part of this liberated energy is used for particle acceleration and to heat up the solar plasma. The Spectrometer/Telescope for Imaging X-rays (STIX) instrument onboard the Solar Orbiter mission launched on February 10th 2020 promises advances in the study of solar flares of various sizes. It is capable of measuring X-ray spectra from 4 to 150 keV with 1 keV resolution binned into 32 energy bins before downlinking. With this energy range and sensitivity, STIX is capable of sampling thermal plasma with temperatures of≳10 MK, and to diagnose the nonthermal bremsstrahlung emission of flare-accelerated electrons. During the spacecraft commissioning phase in the first half of the year 2020, STIX observed 68 microflares. Of this set, 26 events could clearly be identified in at least two energy channels, all of which originated in an active region that was also visible from earth. These events provided a great opportunity to combine the STIX observations with the multi-band EUV imagery from the Atmospheric Imaging Assembly (AIA) instrument on board the earth orbiting Solar Dynamics Observatory (SDO). For the microflares that could be identified in two STIX science energy bands, it was possible to derive the temperature and emission measure (EM) of the flaring plasma assuming an isothermal source. For larger events where more detailed spectra could be derived, a more accurate analysis was performed by fitting the spectra assuming various thermal and nonthermal sources. These results are compared to the diagnostics derived from AIA images. To this aim, the Differential EmissionMeasure (DEM) was reconstructed from AIA observations to infer plasma temperatures and EM in the flaring regions. Combined with the the relative timing between the emission seen by STIX and AIA, this allows us to get deeper insight into the flare energy release and transport processes.</p>

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