In the event of a large-scale forest fire, the Korea Meteorological Administration (KMA)’s weather observation vehicles are deployed to obtain weather information necessary for extinguishing the fire. However, due to the limited number of vehicles and the environment to enter the field, it is difficult to observe the point where the information is actually needed. Therefore, there is an urgent need to develop a weather observation system that is easy to transport and install in the field.

We developed a 'portable weather observation system' that can be easily utilized by anyone, even if the KMA does not support weather observation vehicles and their operators at the disaster site.

 - [Transport] Weight and size that can be easily carried by one adult in a suitcase (or backpack).
 - [Installation] Attached to a steel plate, such as the top of a vehicle without any additional components. If this is not possible, a tripod can be utilized for installation.
 - [Operation] Real-time storage, display, and transmission of observation data
 - [Information] Location of the observation site (latitude, longitude and altitude) and weather variables (temperature, humidity, atmospheric pressure, and wind direction*∙wind speed) of the observation site.
  * Corrected regardless of the system's installation orientation

The prototype consists of a weather observation sensor, two GPS antennas, a tripod, a data processing/storage/display unit, and a power supply unit, and the total weight of the components including the suitcase (10 kg) is 20 kg. The weather observation sensor used is the Vaisala WXT-536, which can observe weather variables. Two GPS antennas were used to determine the location of the sites and correct the wind direction observed by the sensor. The system can be directly utilized by the Korea Forest Service (KFS) and the National Fire Agency (NFA) for initial extinguishment of wildfires.

By applying weather observation data transmitted in real-time from the field to numerical forecasting models, the KMA can provide more accurate weather forecasts back to the field. In the future, we plan to improve the prototype by utilizing an inexpensive sensor and lightweight and long-lasting batteries to reduce the cost and weight as well as increase the operating time.

How to cite: Park, M. E. and Lee, Y. H.: Development of Portable Weather Observation System, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7444, https://doi.org/10.5194/egusphere-egu24-7444, 2024.

According to Korean Statistical Information Service(KOSIS)’s data, the area of the Republic of Korea is 100,444 km² and the area of Seoul, the capital city of Korea, is 605 km², which is only 0.6 % of the area of Korea. However, the population of the Korea is 51.75 million, and that of Seoul is 9.39 million, accounting for a large 18 % of Korea. A large number of these densely populated cities are located in river basins. In most of time, water resources stored upstream are used as various purposes(drinking, industrial, and agricultural use) and drained downstream. During summer monsoon, however, rain that falls in the basin is discharged downstream as quickly as possible to prevent flooding. But heavy, concentrated rain caused by recent climate change often leads to capacity to exceed designed capacity. Moreover, inundation occurred due to neglect of neglect of drain pipe and street inlet and is becoming a serious social problem.

This study was conducted to observe the ‘flood level’ in the city, which is basic data for flood management. We already have the ability to accurately and conveniently measure the water level and transmit the data when flooding occurs at multiple point in the city. To monitor water levels in underpasses and areas where poor drainage is expected, rods on the centerline of roadway or border of the sidewalk are used. The prototype has been completed, and additional work is underway to miniaturize the built-in equipment(board, communication, and battery) and to extend battery duration. To maintain accuracy of measurement in the process of the miniaturization, it is important to secure enough distance between weight and outer case to minimize the surface tension effect. So it is necessary to understand the relationship between the weight-outer case distance and water level observation measurements. This relationship was confirmed through various weights and outer cases. As a result, the accuracy was found to be sufficient when a weight-outer case distance is about 9 mm or longer.

Acknowledgement : This research was support by a (2022-MOIS63-002) of Cooperative Research Method and Safety Management Technology in National Disaster funded by Ministry of Interior and Safety(MOIS, Korea).

How to cite: Jeong, Y., Jo, H. J., Park, S. J., and Kong, O. Y.: Developing gravimetric water level meter, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7295, https://doi.org/10.5194/egusphere-egu24-7295, 2024.

Spaceborne optical sensors are a useful tool for monitoring water quality in oceans, lakes and rivers on a large scale, at high frequency and at relatively low costs. Based on water colour algorithms, many key biogeochemical parameters are operationally estimated from satellite data (e.g. chlorophyll-a concentration). Calibrating and validating these algorithms requires a huge collection of high-quality in situ radiometric data, such as the water-leaving radiance L_w (or the remote sensing reflectance R_rs), necessitating high-level expertise and expensive material.

One of the most robust methods to measure L_w is the skylight-blocked approach (SBA), which allows L_w to be measured directly at the air-water interface. Compared with the conventionnal “above-water” method, the measurement is not contaminated by light reflected from the surface (including both sky- and sun-glint), thanks to the use of a cone-shaped screen attached to the downward-facing radiance sensor (which measures L_w) that fully blocks all downward radiance at the air-water interface.

Our open-source system “Lake SkyWater” was designed around the idea of making in situ radiometry measurements in lakes user-friendly and affordable, while retaining the accuracy and robustness required for scientific and operational purposes. We have created a semi-autonomous buoy that implements the SBA method. Lake SkyWater is low-cost (<1 k€, excluding the cost of the two radiometers), lightweight, and easy to transport and deploy. Our new device addresses one of the main ongoing issues with the SBA protocol: the issue with the radiance sensor measuring water being in the direct sun shadow of the deployment platform.

Our device consists of two commercially available radiometers that use the MODBUS RTU protocol (e.g., TriOS RAMSES G2) controlled by open-source TinkerForge modules and mounted to a rotating platform attached on top of an inner-tube (the buoy). Everything has been optimised for maximal portability (allowing it to be taken on a commercial flight): 1) the buoy is inflatable and 2) the structure is made of lightweight anodised aluminium profiles and PETG 3D-printed parts, and can be disassembled and transported in a suitcase/bag (the longest part measures 745x40x20 mm). The buoy’s position, its absolute orientation as well as its tilt are recorded (thanks to the embedded GNSS receiver and the 9-DOF IMU), and the solar azimuth angle is derived from the buoy’s positioning data. This enables the system to calculate the motor adjustments needed to keep the radiance sensor on the sunny side of the instrument. Our device hosts its own WiFi network and can be controlled wirelessly over a mobile phone, tablet or PC. Additionally, the radiometric buoy can be transformed into a fully autonomous monitoring system by plugging in a Raspberry Pi to act as a data logger.

Lake SkyWater was designed in the context of my PhD thesis dedicated to the calibration and validation of water colour algorithms for Petit-Saut Reservoir in French Guyana.

How to cite: Coqué, A., Peroux, T., Morin, G., and Tormos, T.: Lake SkyWater - a portable optical buoy for easily measuring water-leaving radiance in lakes based on the skylight-blocked approach (SBA), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11069, https://doi.org/10.5194/egusphere-egu24-11069, 2024.

Water clarity regulates light penetration in aquatic environments, influencing both physical and biological dynamics. Its influence extends to heat transfer within the water column, shaping the thermal structure of lakes. Photosynthetically Active Radiation (PAR) in the euphotic zone is the source of energy for light-dependent organisms, which are crucial for ecological balance. The ability to accurately assess water clarity is therefore important in several aquatic science contexts, ranging from data analysis and process interpretation to modelling. Common metrics used to quantify water quality include the vertical attenuation coefficient K_d,PAR, a measure of light penetration, and the Secchi depth (Z_SD), a measure of water visibility. The enduring simplicity and cost effectiveness of the Secchi disk has made it a global standard for measuring water clarity for almost two centuries. In contrast, K_d,PAR is typically determined using expensive instruments designed to measure light in the PAR range. This discrepancy highlights the need for innovative yet cost-effective methods that integrate both types of measurements. In this contribution, we present DISCO, a low-cost instrument that combines the standard and globally used Secchi disk with light attenuation measurement supported by light sensors. DISCO retains the traditional shape of a Secchi disk but is equipped with light-dependent resistors (LDRs), which are used as light sensors both looking up and down. In addition to the LDRs, the disk is also equipped with low-cost temperature and pressure sensors, all connected to an ArduinoUNO board. After calibrating the sensors against commercial instruments, DISCO was tested in two mountain lakes together with high-resolution PAR, temperature and pressure sensors used as a benchmark. The results show that the proposed low-cost instrument is able to reproduce the shape of the light profiles with proper quantification of the light attenuation coefficients. Its affordable cost and ease of construction and use is expected to increase the ability to make measurements in locations where expensive instruments are not available, thereby extending the coverage of water clarity monitoring sites. This in turn has potential implications for wider in-situ calibration of remote sensing products. The prototype of DISCO will be shown at the poster session.

How to cite: Donini, G. and Piccolroaz, S.: DISCO: a low-cost Device-Instrumented Secchi disk for water Clarity Observations, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11187, https://doi.org/10.5194/egusphere-egu24-11187, 2024.

The monitoring of surface water levels in lakes and rivers is essential for adequate water resource management and timely responding to extreme events. Monitoring an entity as large as the Nile river comes with significant challenges. The cross-boundary nature of the Nile, complicates its management due to different jurisdictions and interests, furthermore there are logistical challenges related to accessibility and site safety.

Radar altimetry has the potential to offer remotely sensed water heights, but still requires expert knowledge and site-specific trial and error. Generating in-situ records of water level heights is therefore invaluable activity both for monitoring and validation purposes.

Low-cost Global Navigations Satellite Systems (GNSS) interferometric reflectometry promises a low-cost solution for monitoring water heights, and devices can be locally constructed using off the shelf components which are now widely available. Furthermore, the development of internet of things (IoT) networks in Africa is moving forward and creates opportunities for remotely controlled measurement stations.

Here, we present our activities on designing and deploying low-cost GNSS-R receivers on the shores of Lake Victoria. We show several designs based on raspberry Pi’s and a low-power version based on the Actinius Icarus platform (zephyr based). We further explore possibilities to apply on-board processing of GNSS signal to noise ratio series, which will pave the way for using low bandwidth networks.

How to cite: Rietbroek, R., K. Challa, Z., Kizza, M., Zaroug, M., Kanyike, T., and Wara, C.: Leveraging inland radar altimetry over rivers with low cost GNSS reflectometry, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15584, https://doi.org/10.5194/egusphere-egu24-15584, 2024.

Different types of sensors are used continuously or intermittently in urban water management systems. They are primarily useful for monitoring and controlling medium to large treatment plants, allowing the recording of physical parameters such as inflow and/or outflow rates or the temperature of the facilities (Murphy et al., 2015). Additionally, continuously measured parameters include those specifically used to monitor physico-chemical processes throughout the treatment: electrical conductivity, pH, turbidity, redox potential, or dissolved oxygen in the basins, as well as insufflated air flow rates. For smaller-scale stations (< 2,000 EH), water quality monitoring is often more limited, frequently confined to batch counting or using malfunction sensors (for instance, effluent overflow).Furthermore, taking the example of reed bed filters (RBF), which are primarily advantageous for operators due to their operational simplicity, the use of sensors could be seen as complicating this system primarily intended for rural areas (Rao et al., 2013). The costs of purchasing and maintaining measurement chains may appear excessively high depending on the parameters used, an opinion shared by municipalities and operators whose financial resources are increasingly constrained (Prost-Boucle et al., 2022). The issue of sensor costs is particularly significant for smaller stations, significantly impacting operational budgets. It is also worth noting the difficulty in repairing and maintaining these solutions, often regarded as black boxes for users, requiring complete upgrades at regular intervals. As part of the Setier project, we have developed a series of Open-hardware tools for the management and monitoring of wastewater treatment plants. The objective of our presentation will be to showcase an open-source ultrasonic flowmeter. This flowmeter allows monitoring variations in Venturi channels, encompassing heights from 0 to 1 meter. It offers a 1mm resolution, and all design elements are shared online. The uniqueness of our system lies in its requirement for no component soldering like “Lego”. The flowmeter is programmable via the Arduino IDE. As for data collection, it is done using a smartphone through a web server embedded in the Arduino MKR1010 Wifi board. Our presentation will highlight the first measurement results from a 6-month wastewater treatment plant.

Murphy, K., Heery, B., Sullivan, T., Zhang, D., Paludetti, L., Lau, K.T., Diamond, D., Costa, E., O׳Connor, N., Regan, F., 2015. A low-cost autonomous optical sensor for water quality monitoring. Talanta 132, 520–527. https://doi.org/10.1016/J.TALANTA.2014.09.045

Prost-Boucle, S., Kamgan Nzeufo, H., Bardo, T., Moreau, S., Guyard, H., Duwig, C., Kim, B., Dubois, V., Gillot, S., Clement, R., 2022. Capteurs bon marché et centrales d’acquisition DIY pour les eaux usées : le projet Setier: Low-cost sensors and datalogger open hardware for wastewaters: Setier project. TSM 35–44. https://doi.org/10.36904/tsm/202201035

Rao, A.S., Marshall, S., Gubbi, J., Palaniswami, M., Sinnott, R., Pettigrovet, V., 2013. Design of low-cost autonomous water quality monitoring system. Presented at the 2013 International Conference on Advances in Computing, Communications and Informatics (ICACCI), pp. 14–19. https://doi.org/10.1109/ICACCI.2013.6637139

How to cite: Imig, A., Guyard, H., Prost-boucle, S., Quatela, V., Moreau, S., Sudre, J., and Clément, R.: SETIER Project: An open source flowmeter for monitoring flow rates output of waste water treatment, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16629, https://doi.org/10.5194/egusphere-egu24-16629, 2024.

The recognition of global change impacts on catchments and the waters they drain emphasizes the need to better understand and predict both hydrological and biogeochemical dynamics at the terrestrial-aquatic interface. To achieve this great endeavor, a key priority is to substantially increase the number of multi-annual time series, covering a broad range of river types and filling existing geographical gaps (e.g., low-income regions in/and remote areas). However, commercial multi-sensor solutions are not affordable to everyone. The multi-sensor platform consists of a STM32 micro-controller board combined with a data logger module, and a set of sensors to measure hydro-chemical properties both at different depths in soils (adjacent to the streams) as well as within streams: temperature, water level, moisture, electrical conductivity, turbidity, dissolved O₂ and CO₂. The monitoring system is also equipped with a wireless communication capability using LoRa network technologies. To make our project as accessible as possible, we have designed, built, and programmed the multi-sensor adopting the Open Source Hardware and Software philosophy. Through the complete processes of pre-calibration and in situ measurement, the preliminary results illustrate that the proposed multi-sensor system can provide long-term, high-frequency hydrological and biogeochemical data across land-stream interfaces while keeping the balance of costs and accuracy.

How to cite: Gómez Gener, L., Wiedmer, A., and Camarero Galindo, L.: A low-cost multi-sensor platform for monitoring real-time hydrological and biogeochemical dynamics across land-stream interfaces, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18913, https://doi.org/10.5194/egusphere-egu24-18913, 2024.

Open hardware-based microcontrollers, especially the Arduino platform, have become a comparably easy-to-use tool for rapid prototyping, stand-alone systems and implementing creative solutions. Such devices in combination with dedicated frontend electronics, external sensors and modems can offer low cost alternatives for student projects and independently operating small scale instrumentation. The capabilities of sensor-to-sensor communication can be extended to data taking and signal analysis at decent rates. Low-cost approaches to environmental monitoring will be critical for developing the evidence base needed to better understand the climate system, specifically in our case for understanding the water cycle. Off-the-shelf-components-based, internet-connected devices are easy to monitor and maintain, low risk and capable of extensive deployment to address the challenge of geographical variability and can address user- and site-specific demands. We present our project of a data logger platform "nCollector" based on an Arduino DUE, including data storage on SD cards, serial data transmission via USB, RS485, SDI-12, telemetry via GSM (4G), Nb-IoT and LoRa including its power supply and a minimal user interface. For outdoor instrumentation we specifically designed a solution with a low power demand of 0.2 W in order to realize 24/7 operation under harsh conditions with medium sized PV panels and batteries. With our presentation we want to provide a model case for other researchers to take inspiration from, share our experience with building and deploying over 100 systems all over Europe and help engaging the community to enhance their own instrumentation and data taking. 

How to cite: Weimar, J. and Köhli, M.: Open-hardware-based data logger platform for independently operating outdoor instrumentation, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19610, https://doi.org/10.5194/egusphere-egu24-19610, 2024.

In this study, we propose a novel approach for precipitation measurement based on rainfall acoustics, utilizing an effective rainfall acoustic collection device with low-cost IoT sensors housed in waterproof enclosure. Here, rainfall acoustics refer to the sound generated when raindrops fall and collide with surfaces such as the ground or canopy. Even at the same rainfall intensity, depending on the medium with which raindrops collide, acoustics with different frequency characteristics may occur. In this research, an acoustic collection device, combining a Raspberry Pi and a condenser microphone, was inserted into a waterproof enclosure and deployed in a rainfall environment to collect rainfall acoustics. This approach not only controls the medium of rainfall acoustics but also effectively blocks ambient noise and water, ensuring consistent characteristics of rainfall acoustics regardless of the installation environment. The collected rainfall acoustics were segmented into 10-second intervals, and spectrograms in the frequency domain were extracted by applying Short-Time Fourier Transform for each segment. Finally, using the extracted spectrogram as input data, a rainfall intensity estimation model based on a convolutional neural network was developed and other precision rainfall observation instruments (e.g., PARSIVEL, Pluvio², etc.) were considered collectively for the validation of the developed rainfall intensity estimation model. Acoustic-based rainfall observation enables the establishment of a dense observation network using low-cost devices. Leveraging the high temporal resolution of acoustic data, extremely short observation periods for rainfall can be achieved. This methodology presents an opportunity for cost-effective and high-spatiotemporal-resolution rainfall observation, overcoming the limitations of traditional methods.

Keywords: Acoustic Sensing, Rainfall Acoustics, Precipitation, Convolutional Neural Network

Acknowledgement

This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. RS-2023-00250239) and in part by the Korea Meteorological Administration Research and Development Program under Grant RS-2023-00243008.

This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No.NRF-2022R1A4A3032838).

How to cite: Hwang, S., Lee, J., Byun, J., Park, K., and Jun, C.: Rainfall Intensity Estimation Based on Raindrops Sound: Leveraging the Convolutional Neural Network for Analyzing Spectrogram, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19085, https://doi.org/10.5194/egusphere-egu24-19085, 2024.