Displays

Research of surface runoff, retention and infiltration processes consequenced with soil erosion by water is worldwide problem. There are numerous of natural and artificial research methods to study this phenomena. Use of rainfall simulators is one of the most popular artificial method. There are many types of rainfall simulators, we are introducing new type of portable nozzle-type rainfall simulator. This device combines advantages of pulse and swiping nozzle droplet generation. Device criteria were: (i) 2 person operation (ii) low water consumption (iii) wide range of rainfall intensity and kinetic energy. The simulator is supported by 4 metal legs. One fast-replaceable nozzle is placed above the center of a plot in 2 or 2,5 m height. Nozzle is connected to a control unit with stepper motor which allows it to swing, or stay in the vertical position with water flow interruption (solenoid valve). Required rainfall intensity is controlled by the velocity of stepper motor and water flow interruption periods. Metal collector is placed under the nozzle to drain the surplus water back to the reservoir. Standalone electric water pump is used to pump water into the system. 12 V DC and 230 V AC electricity supply is needed to run the device. Experimental plot can be up to 4 m² (2x2 m square) in size but usually a 1 m² (1x1 m) is used. Rainfall intensity could be used up to 100 mm h^-1. Kinetic energy for the tested nozzles were 4 – 5,5 J m^-2 mm^-1. The first testing shows Christiansen Uniformity up to 93% for 1 m² plot and 73% for 4 m² plot. The research has been carried out within the framework of projects QK1910029, TJ02000234 and TH02030428.[M3] 

How to cite: Neumann, M., Kavka, P., Laburda, T., and Tejkl, A.: Swiping/pulse portable nozzle rainfall simulator, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2936, https://doi.org/10.5194/egusphere-egu2020-2936, 2020

Research of the evaporation from the water surface is curtailing for measuring the water balance in small catchments.

An ongoing project aims to develop a simple and reliable, easy to reproduce evaporation measuring device. A core part of the device is measuring the water level in the field in cheap form. 3D printed design in combination with open-source cheap electronics is utilized. Methodology and results of the ongoing research project will be presented. The project investigates the affordable and simple technical measures that have the potential to increase the number of opportunities for the measuring of evaporation.

Continuously the theories are developed and tested, subsequently, conclusions are implemented into the next generation of the device. Five generations of 3D printed part have been done, and now the research focus on the electrical and software part of the device. Durability and reliability of the device are tested in the field, in three locations. All plots are also frequently checked by research staff and data is saved and later compared with data measured by the device. Refilling of the evaporation pan is also done by research staff.

Prototype 3 used the experience of all previous prototypes. The construction is equipped with 5 sets of electrodes, each with a measuring range of 10 mm. The total measuring range is 50 mm. The whole structural part of prototype 3 is designed as a printout on a 3D printer, electrodes are printed from a conductive material. Above the electrodes, there is a printed circuit board carrying the microelectronics control module.

The principle of measurement consists of gradual interrogation of the set of electrodes, a subsequent reversal of polarity and repeated interrogation. This cycle is repeated several times and the result is averaged, then the next set is measured. The polarity reversal is controlled by the relay. Thanks to the use of printed circuit board it was possible to simplify the device, so only 7 wires, one analog output, polarity reversal control and supply wire to 5 sets of electrodes are led from the whole device.

An important step in the evaluation of the obtained data (the values of current passed through the water), is its analysis. Because values are read very often they differ only slightly. A commonly used vapor unit is mm of water column per day. It is, therefore, necessary to analyze a long time series, at least longer than one day, and covering the entire day from 00:00 to 23:59.

The testing sites are the grounds of the CTU Faculty of Civil Engineering in Dejvice, the experimental sites of the CULS in Prague Suchdol and the Water Research Institute in Prague Podbaba.

The research is funded by the Technological Agency of the Czech Republic (research project TJ02000351 - Development of Tools and Methods Improving Estimation of annual Evaporation Balance).

How to cite: Tejkl, A. and Kavka, P.: Low cost Evaporometers, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4999, https://doi.org/10.5194/egusphere-egu2020-4999, 2020

Measurement of runoff events induced by natural rainfall or rainfall simulators of various construction and dimensions is a common method for obtaining data needed for run-off and soil erosion models calibration. As every simulator is different so are the methods for data collection, recording, processing and utilization. Mining the data from different sources for comparison or a common purpose can be quite exhausting as all the teams and workers use different software, workflows and structures for storing the data. The database presented is an attempt to provide a robust structure for storing experimental data together with its metadata, relationships between data sets and other information about the data collection and preprocessing. The desired state is where any record is back-trackable to the original source field record regardless if it was written by hand on paper or registred by digital logger.

The relational database is built in MySQL and provides a comprehensive structure for storing and retrieving the data and metadata. The access to the database is differentiated into multiple levels with different rights. A public web user interface allows low-level access to the data that can be viewed as tables and charts. Private web interface provides logged-in users the rights to add, delete and alter data. The web interface incorporates basic search, order and filter capabilities on the data. High level access by direct querying the DB is available for trusted users who are familiar with MySQL language and so are capable of creating their own complex queries. The direct access to the database is possible via any programing language with appropriate libraries. Querying the DB directly by code comes especially handy when preparing extensive datasheets for statistical evaluation or model calibration runs.

The database follows the “FAIR Guiding Principles for scientific data management and stewardship”.

So far the database was successfully tested on the data from the three institutions of the authors' affiliation . Further development and tuning of the DB to enable incorporation of wider range of data structures is desired and any suggestions are welcome. If you are dealing with measurements related to rainfall-runoff processes and are interested in making your data accessible, please bring a typical dataset or an overview of recorded parameters to this PICO.

The research has been supported by the research project QK1810341 of Czech National Agricultural Research Agency and the European Social Fund in the Free State of Saxony (Förderbaustein: Promotionen)

How to cite: Devátý, J., Beitlerová, H., and Lenz, J.: An open rainfall-runoff measurement database, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9148, https://doi.org/10.5194/egusphere-egu2020-9148, 2020

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!

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.

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!

How to cite: Isidoro, J., Pattison, I., Iserloh, T., de Lima, J., Green, D., Marzen, M., de Lima, I., Silveira, A., and Stirling, R.: A (small) step towards standardisation in rainfall simulation experiments, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18556, https://doi.org/10.5194/egusphere-egu2020-18556, 2020

The Moroccan argan woodlands form a unique ecosystem that is at acute risk of degradation and desertification. Beside the great impact on local and regional socio-economical structure, the characteristic landscape is assumed to protect populated and agriculturally productive areas such as the Souss-Massa-region against desertification processes from the adjacent desert areas in Southwest Morocco and Algeria.

The experimental-empirical study with the Trier Portable Wind Simulator was conducted to quantify sediment mobilisation by wind on various surface characteristics associated to argan woodlands under extensive agro-silvo-pastoral management. Tested surfaces included physical and biological crusts, stone and litter cover and ploughed surfaces.

We found that the argan woodlands of the Souss region may be a significant source of wind eroded sediment particularly facing effects of overexploitation and climate change. An adapted land management is key to prevent severe dust production and mitigate possible impacts of land use change and climate change related shifts in wind and rainfall patterns.  

How to cite: Marzen, M., Mario, K., Irene, M., Ali, A. H., and Ries, J. B.: Wind erosion in Moroccan argan woodlands under extensive agro-silvo-pastoral management, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-15068, https://doi.org/10.5194/egusphere-egu2020-15068, 2020

The phenomenon of splash caused by water drop has been widely studied in recent years. There are many measurement methods, including the method based on the use of so-called high-speed cameras. Due to the possibility of recording of the phenomenon with a high time frequency (thousands of recorded frames per second), this method provides detailed information about the process of splashed particles, which were previously unavailable. These include, among others, precise tracking of single ejected particles, determination of their ejection angle, displacement distance, and division of splashed elements into groups depending on the place or moment of ejection from the particle bedding. Despite the numerous advantages of the method, there is no information about the percentage of splashed particles that the cameras are able to detect and identify. In order to determine such effectiveness, it is necessary to have a reference method that guarantees 100% identification of splashed particles.

The aim of this work was to determine the effectiveness of high-speed cameras in identification of particles ejected from the granular bedding during the water drop impact. Sticky paper was used as a reference method.

Dry spherical glass beads (425–600 μm size range), which were placed into an aluminium ring (30mm diameter, 10mm height) were used in the experiments. The aluminum ring was placed in a drilled hole (only slightly larger than the ring) in a horizontal wooden plate, and therefore, the surface of the beads was at the same level as the surrounding plane. Drops (d=4.2mm) of distilled water were created in a peristaltic pump and fell free from 1.5m. The final velocity of each drop was 4.98 m/s.

Three synchronized Phantom Miro M310 cameras were used to register the splash phenomenon (307 μs time interval, 1280x800 px resolution). The camera calibration process facilitated analysis of the trajectories of the splashed particles and determination of their velocities, ejection angles, and displacement distances. The analysis of the recorded images was carried out using the Dantec Dynamics Studio software. The particles were tracked by the Volumetric 3DPTV module, and the trajectories were further analyzed by our script written in LabVIEW.

A hole (30mm diameter) was cut out of a piece of sticky paper, and the paper was placed concentrically over the ring. This allowed recording of all splashed particles while avoiding their rebounding or rolling from the plane. Following the impact, the beads were photographed using a Nikon D7100 camera, and images were analyzed using ImageJ software. The number of particles and the distance from the geometrical center of the drop impact were recorded.

Measurements using the high-speed cameras and the sticky paper method were carried out in 16 repetitions.

The results obtained with both methods were compared with each other. Regarding the sticky paper method as a reference, the efficiency of identification with the high-speed cameras for the splash of glass beads was determined, which was estimated at 53%.

The study was partially funded by the National Science Centre, Poland, in the frame of the project no. 2017/26/D/ST10/01026.

How to cite: Sochan, A., Beczek, M., Mazur, R., Ryżak, M., Łagodowski, Z., Nieznaj, E., Bobrowski, A., and Bieganowski, A.: Determination of the effectiveness of high-speed cameras for identifying ejection particles during splash with regard to the sticky paper method, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-16225, https://doi.org/10.5194/egusphere-egu2020-16225, 2020

The Sustainable Development Goal 4 of UN 2030 Agenda requires the implementation of education for sustainable development and sustainable lifestyle. In this context, Earth Sciences and related disciplines such as Environmental and Soil Sciences are fundamental teachings in any school to make younger generations aware about the effects of geological processes and human activities on climate change and to achieve possible solutions for sustainability. This aim clashes with the student difficulties in learning geosciences. In particular scientific terminology, abstract concepts, and depth of geological time make Earth Sciences difficult to understand and less attractive than others disciplines (King, 2012). As one of the hardest tasks for students is visualising unseen processes, Inquiry-Based Science Education (IBSE) is one of the best approaches to contrast this trend. This is an empirical learning method, based on “inquiry”, where students are encouraged to solve problems and explain phenomena, performing experiments. Despite in 1996 the USA National Science Education Standards defined IBSE as the best approach in natural science teaching, the majority of European classrooms are not implementing them (Rocard et al., 2007).

NOVA A.P.S. (Ferrara, Italy) promotes and disseminates STEAM (Science, Technology, Engineering, Arts, Mathematics) disciplines in secondary schools using the IBSE method. To evaluate the success of this approach, NOVA asked ninety 11-year-old students from an Italian school to perform a questionnaire about “Greenhouse gases: nature, potential sources, and effects on climate” after studying the theory with traditional frontal lessons. The questionnaire was proposed again to same group after the application of IBSE approach through its “5E” phases (Engage, Explore, Explain, Elaborate, Evaluate; Bybee, et al., 2006). Students were engaged to confirm the greenhouse theory exploring the phenomena in small different ecosystems built in cut-in-half plastic bottles, partially filled with 1) soil and 2) soil with plants, covered at the top with plastic wrap and exposed to sunlight. Another bottle with soil remained unwrapped to study also the potential effects in “absence of atmosphere”. For each bottle temperature changes and CO₂ emissions were monitored with sensors connected to Arduino boards. The comparison of these parameters in different ecosystems and conditions led students to explain the greenhouse effect and elaborate this concept revealing also i) difference between global warming phenomena and greenhouse effect (a common misconception); ii) relevant role of soils on CO₂ emissions; iii) importance of vegetation in preventing the rising temperature. Finally, students were encouraged to self-evaluate the new acquired knowledge. The future task of this project is creating a sharing platform for teachers, where downloading instructions of the experiment and questionnaire form, and, in turn, uploading feedbacks. Testing and evaluating this method could bring teachers to combine traditional deductive lessons with more practical and stimulating approaches.

Bybee R.W., et al. (2006). The BSCS 5E Instructional Model: Origins, effectiveness and applications. Retrieved from http://www.bscs.org/bscs-5e-instructional-model

King H. (2012). Student difficulties in learning geoscience, Planet, 25, 40-47.

Rocard M., et al. (2007). Science Education NOW: A renewed Pedagogy for the Future of Europe, Luxembourg, Office for Official Publications of the European Communities.

How to cite: Brombin, V., Calore, E., D'Onofrio, R., Lauro, C., Marchina, C., and Pelorosso, B.: SCIENCHY - catchy science with IBSE approach, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18081, https://doi.org/10.5194/egusphere-egu2020-18081, 2020

The researches carried out by the AIGeo (Italian Association of Physical Geography and Geomorphology) members, also in collaboration with other researchers, cover various important topics of the Environmental and Earth Sciences. Geomorphology is central, also in the framework of dissemination strategies that are implemented and elaborated. A particular focus is, in fact, addressed to the development of educational strategies and applications focusing on landscape evolution through space and time having as target both students and teachers. The proposed strategies include fieldworks, multimedia activities and multidisciplinary approaches addressed mainly to secondary schools. In the Italian framework, the Ministerial National Guidelines provide indications about teaching these topics in the secondary schools. The guidelines indicate specifically, for the secondary schools of 2nd level, the topics and novelties concerning Physical Geography and Geomorphology. Among the general goals referred to the secondary school of 1st level, the landscape observation and the related natural phenomena are approached by the Geography teachers and by the Science teachers. Herein, we present an overview on the AIGeo activities regarding education in Physical Geography and Geomorphology. Some examples of the most recent researches planned and tested for the secondary school (1st and 2nd level) will be outlined. Moreover, the initiatives addressed specifically to present and future teachers will be illustrated too.

How to cite: Bollati, I. M.: Developing new approaches and strategies for teaching Physical Geography and Geomorphology: the role of AIGeo (Italian Association of Physical Geography and Geomorphology), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-22102, https://doi.org/10.5194/egusphere-egu2020-22102, 2020