scholarly journals Study on Water Level Prediction Using Observational Data from a Multi-Parameter Phased Array Weather Radar

2021 ◽  
Vol 16 (3) ◽  
pp. 410-414
Author(s):  
Kazuhiro Yoshimi ◽  
Masakazu Wada ◽  
Yukio Hiraoka ◽  
◽  
Keyword(s):  
Water Level ◽  
Observational Data ◽  
Urban Areas ◽  
High Speed ◽  
Phased Array ◽  
Three Dimensional ◽  
Weather Radar ◽  
Water Levels ◽  
Hydrological Processes ◽  
Basic Study

A dual-polarization, phased array weather radar, also known as the multi-parameter phased array weather radar (MP-PAWR), was developed by the Japanese Cross-ministerial Strategic Innovation Promotion (SIP) Program. Since this weather radar has been made into an active phased array, three-dimensional observation of weather phenomena can be realized at high speed by means of electrical scanning in the elevation direction and mechanical scanning in the azimuth direction. This is expected to shed light on hydrological processes in river basins, such as those of urban rivers, and improve prediction accuracy. In this study, river water levels in urban areas were estimated from vertically integrated liquid (VIL) Nowcast water content results, a meteorological forecasting method based on the three-dimensional observation MP-PAWR data, using a synthesized rational formula. A runoff analysis for urban basins was carried out using the rainfall forecast results based on MP-PAWR observational data. Since it is known that this formula can be used to deliver a rapid response time for runoff phenomena in the basin, it is possible to fully exploit the features of the MP-PAWR. This study shows how MP-PAWR is used in a series of hydrological processes. In this paper, we report the results of a basic study on water level predictions based on MP-PAWR observational data and also present future prospects for the use of this technology.

scholarly journals High-Speed Volumetric Observation of a Wet Microburst Using X-Band Phased Array Weather Radar in Japan

2016 ◽  
Vol 144 (10) ◽  
pp. 3749-3765 ◽  
Author(s):  
Toru Adachi ◽  
Kenichi Kusunoki ◽  
Satoru Yoshida ◽  
Ken-ichiro Arai ◽  
Tomoo Ushio
Keyword(s):  
High Speed ◽  
Phased Array ◽  
Three Dimensional ◽  
Weather Radar ◽  
Ground Level ◽  
Dimensional Structure ◽  
Convection Cell ◽  
Low Level ◽  
X Band ◽  
Traffic Operation

This paper reports a high-speed volumetric observation of a wet microburst event using X-band phased array weather radar (PAWR) in Japan. On 10 September 2014, PAWR observed the three-dimensional structure of a convection cell, which had a vertical extent of 5–6 km and a horizontal dimension of 2–10 km, moving toward the east-northeast. At 2310 Japan standard time (JST), a precipitation core with a radar reflectivity of >40 dBZ appeared at 3–5 km above ground level. The core then increased in size and intensity and rapidly descended to the ground. During this time, a reflectivity notch associated with midlevel inflow was initially formed near the top of the precipitation core and, subsequently, at lower altitudes. A strong low-level outflow with a radial divergence of >4 × 10−3 s−1 appeared just below the notch at around 2321 JST. The outflow lasted for approximately 13 min and eventually disappeared after 2333 JST along with dissipation of the causative storm cell. These results suggest that, in addition to hydrometeor loading, evaporative cooling due to the entrainment of midlevel relatively dry air played an additional role in driving a strong downdraft. The preceding signatures including descending precipitation core, reflectivity notch, and midlevel convergence observed by PAWR are useful precursors to forecast the occurrence of low-level wind shear 5–10 min ahead, which is important for safe air traffic operation.

scholarly journals Three-dimensional observations of heavy rainfall using a phased-array weather radar

2014 ◽  
Vol 34 (135) ◽  
pp. 4-9
Author(s):  
Fusako ISODA ◽  
Shinsuke SATOH ◽  
Hiroshi HANADO ◽  
Nobuhiro TAKAHASHI ◽  
Fumihiko MIZUTANI ◽  
...  
Keyword(s):  
Heavy Rainfall ◽  
Phased Array ◽  
Three Dimensional ◽  
Weather Radar

scholarly journals Integrate Weather Radar and Monitoring Devices for Urban Flooding Surveillance

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 825 ◽  
Author(s):  
Shih-Yen Hsu ◽  
Tai-Been Chen ◽  
Wei-Chang Du ◽  
Jyh-Horng Wu ◽  
Shih-Chieh Chen
Keyword(s):  
Real Time ◽  
Urban Areas ◽  
Weather Radar ◽  
Water Levels ◽  
Mitigation Measures ◽  
Extreme Weather Events ◽  
Television System ◽  
Urban Flood ◽  
Flood Monitoring ◽  
Image Capturing

With the increase of extreme weather events, the frequency and severity of urban flood events in the world are increasing drastically. Therefore, this study develops ARMT (automatic combined ground weather radar and CCTV (Closed Circuit Television System) images for real-time flood monitoring), which integrates real-time ground radar echo images and automatically estimates a rainfall hotspot according to the cloud intensity. Furthermore, ARMT combines CCTV image capturing, analysis, and Fourier processing, identification, water level estimation, and data transmission to provide real-time warning information. Furthermore, the hydrograph data can serve as references for relevant disaster prevention, and response personnel may take advantage of them and make judgements based on them. The ARMT was tested through historical data input, which showed its reliability to be between 83% to 92%. In addition, when applied to real-time monitoring and analysis (e.g., typhoon), it had a reliability of 79% to 93%. With the technology providing information about both images and quantified water levels in flood monitoring, decision makers can quickly better understand the on-site situation so as to make an evacuation decision before the flood disaster occurs as well as discuss appropriate mitigation measures after the disaster to reduce the adverse effects that flooding poses on urban areas.

Development of Multi-Parameter Phased Array Weather Radar (MP-PAWR) and Early Detection of Torrential Rainfall and Tornado Risk

2019 ◽  
Vol 14 (2) ◽  
pp. 235-247 ◽  
Author(s):  
Nobuhiro Takahashi ◽  
Tomoo Ushio ◽  
Katsuhiro Nakagawa ◽  
Fumihiko Mizutani ◽  
Koyuru Iwanami ◽  
...  
Keyword(s):  
Local Governments ◽  
Phased Array ◽  
Three Dimensional ◽  
Weather Radar ◽  
Three Dimensional Model ◽  
Strategic Innovation ◽  
Numerical Predictions ◽  
Demonstration Experiment ◽  
The Social ◽  
Torrential Rainfall

This paper is an overview of a project concerned with “Early warning for torrential rainfall/tornado” under “Enhancement of Societal Resiliency against Natural Disasters,” which is one of eleven themes of the SIP (Cross-ministerial Strategic Innovation Promotion Program under the Council for Science, Technology and Innovation, the Cabinet Office, Government of Japan). The characteristics of the project are the development of a multi-parameter phased array weather radar (MP-PAWR) that enables the accomplishment of an accurate three-dimensional model of precipitation over 30 s within a 60 km radius. Various products developed ducts using MP-PAWR and other observations, and numerical predictions, are also discussed, with a demonstration experiment to provide early warnings for torrential rainfall and related disasters. For end users such as local governments and general citizens, the final goal of this project is the social implementation of these products.

scholarly journals Experimental Study of Dam-Break-Like Tsunami Bore Impact Mechanism on a Container Model

2020 ◽  
Vol 27 (1) ◽  
pp. 53-59
Author(s):  
Cheng Chen ◽  
Jun Chen ◽  
Peng Lin ◽  
Chiwei Chen ◽  
Haozhe Chen
Keyword(s):  
Water Level ◽  
High Speed ◽  
Tsunami Wave ◽  
Dam Break ◽  
Water Levels ◽  
Level Gauge ◽  
Impact Mechanism ◽  
Tsunami Waves ◽  
Movement Distance ◽  
Container Model

AbstractTsunami disasters have frequently occurred in recent years. More and more researchers are focusing on this topic. To investi-gate the tsunami bore impact mechanism on a container model, a multi-functional slope-changing tsunami flume is built in this study. To simulate a tsunami bore, a dam-break wave was generated by a free-falling gate in a reservoir. A needle water level gauge and a high-speed camera were used to measure the tsunami wave heights and velocities for different storage water levels in the test flume, and the corresponding Froude numbers of tsunami waves were also calculated. The factors af-fecting the movement distance of the tsunami wave impacting the container model are explored in this experiment, and the results show that the movement distance is positively correlated with the storage water level, and negatively correlated with the container density and the coast slope.

scholarly journals A Multi-Platform Hydrometeorological Analysis of the Flash Flood Event of 15 November 2017 in Attica, Greece

2018 ◽  
Vol 11 (1) ◽  
pp. 45 ◽  
Author(s):  
George Varlas ◽  
Marios N. Anagnostou ◽  
Christos Spyrou ◽  
Anastasios Papadopoulos ◽  
John Kalogiros ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Level ◽  
Urban Areas ◽  
Flash Flood ◽  
Weather Prediction ◽  
Weather Radar ◽  
Flood Event ◽  
Wave System ◽  
Dual Polarization ◽  
X Band

Urban areas often experience high precipitation rates and heights associated with flash flood events. Atmospheric and hydrological models in combination with remote-sensing and surface observations are used to analyze these phenomena. This study aims to conduct a hydrometeorological analysis of a flash flood event that took place in the sub-urban area of Mandra, western Attica, Greece, using remote-sensing observations and the Chemical Hydrological Atmospheric Ocean Wave System (CHAOS) modeling system that includes the Advanced Weather Research Forecasting (WRF-ARW) model and the hydrological model (WRF-Hydro). The flash flood was caused by a severe storm during the morning of 15 November 2017 around Mandra area resulting in extensive damages and 24 fatalities. The X-band dual-polarization (XPOL) weather radar of the National Observatory of Athens (NOA) observed precipitation rates reaching 140 mm/h in the core of the storm. CHAOS simulation unveils the persistent orographic convergence of humid southeasterly airflow over Pateras mountain as the dominant parameter for the evolution of the storm. WRF-Hydro simulated the flood using three different precipitation estimations as forcing data, obtained from the CHAOS simulation (CHAOS-hydro), the XPOL weather radar (XPOL-hydro) and the Global Precipitation Measurement (GMP)/Integrated Multi-satellitE Retrievals for GPM (IMERG) satellite dataset (GPM/IMERG-hydro). The findings indicate that GPM/IMERG-hydro underestimated the flood magnitude. On the other hand, XPOL-hydro simulation resulted to discharge about 115 m3/s and water level exceeding 3 m in Soures and Agia Aikaterini streams, which finally inundated. CHAOS-hydro estimated approximately the half water level and even lower discharge compared to XPOL-hydro simulation. Comparing site-detailed post-surveys of flood extent, XPOL-hydro is characterized by overestimation while CHAOS-hydro and GPM/IMERG-hydro present underestimation. However, CHAOS-hydro shows enough skill to simulate the flooded areas despite the forecast inaccuracies of numerical weather prediction. Overall, the simulation results demonstrate the potential benefit of using high-resolution observations from a X-band dual-polarization radar as an additional forcing component in model precipitation simulations.

Precipitation Nowcasting with Three-Dimensional Space–Time Extrapolation of Dense and Frequent Phased-Array Weather Radar Observations

2016 ◽  
Vol 31 (1) ◽  
pp. 329-340 ◽  
Author(s):  
Shigenori Otsuka ◽  
Gulanbaier Tuerhong ◽  
Ryota Kikuchi ◽  
Yoshikazu Kitano ◽  
Yusuke Taniguchi ◽  
...  
Keyword(s):  
Phased Array ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Weather Radar ◽  
Convective Precipitation ◽  
Dimensional Space Time ◽  
3D Volume ◽  
New Generation ◽  
Time Extrapolation ◽  
Three Dimensional Space

Abstract The phased-array weather radar (PAWR) is a new-generation weather radar that can make a 100-m-resolution three-dimensional (3D) volume scan every 30 s for 100 vertical levels, producing ~100 times more data than the conventional parabolic-antenna radar with a volume scan typically made every 5 min for 15 scan levels. This study takes advantage of orders of magnitude more rapid and dense observations by PAWR and explores high-precision nowcasting of 3D evolution at 1–10-km scales up to several minutes, which are compared with conventional horizontal two-dimensional (2D) nowcasting typically at O(100) km scales up to 1–6 h. A new 3D precipitation extrapolation system was designed to enhance a conventional algorithm for dense and rapid PAWR volume scans. Experiments show that the 3D extrapolation successfully captured vertical motions of convective precipitation cores and outperformed 2D nowcasting with both simulated and real PAWR data.

scholarly journals Analysis of a Precipitation System that Exists above Freezing Level Using a Multi-Parameter Phased Array Weather Radar

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 755
Author(s):  
Nobuhiro Takahashi
Keyword(s):  
Vertical Velocity ◽  
Vertical Profile ◽  
Phased Array ◽  
Three Dimensional ◽  
Weather Radar ◽  
Cloud Base ◽  
Doppler Velocity ◽  
Freezing Level ◽  
Precipitation System ◽  
Fall Speed

An X-band multi-parameter phased array weather radar (MP-PAWR) was developed in 2017. The scan concept of the MP-PAWR is electronic scanning in elevation by combining fan beam transmissions and pencil beam receptions with digital beam-forming techniques and mechanical scanning along the azimuth. The MP-PAWR realized three-dimensional (60 km in radius and 15 km in height) observations without gaps of 30 s. Although the MP-PAWR is supposed to be suitable for observations of rapidly changing convective systems, it can be advantageous for observations of stratiform rainfall because of continuous vertical pointing observations and its ability to apply the Velocity Azimuth Display (VAD) method with a constant radius for a vertical profile of dynamic parameters such as divergence and deformation. In this study, a precipitation system that existed mainly above the freezing level (in this case, it was approximately 5 km in height) observed from 14:00 to 17:00 Japan Standard Time on 6 September 2018 was analyzed using MP-PAWR data. The averaged area of the vertical profile of Z, and the Doppler velocity with fixed elevation showed a stationary structure with time. The average differential reflectivity factor (ZDR) profile with fixed elevation angles showed values that were close to zero and increased with height. Similar characteristics were shown in the average Specific Differential Phase (KDP) profile. Vertical pointing data, especially for Z, ZDR, and Doppler velocity, were utilized when the echo passed over the radar site, and the Doppler velocity showed the acceleration of fall speed below the freezing level. The vertical profile of divergence with a fixed radius was calculated using the VAD method, and the vertical velocity was calculated using the fall speed profile from the vertical pointing data and by assuming the vertical velocity at the cloud base was zero. The results indicate that the updraft region corresponds to higher ZDR and KDP regions.

scholarly journals Short Term Real-Time Rolling Forecast of Urban River Water Levels Based on LSTM: A Case Study in Fuzhou City, China

2021 ◽  
Vol 18 (17) ◽  
pp. 9287
Author(s):  
Yu Liu ◽  
Hao Wang ◽  
Wenwen Feng ◽  
Haocheng Huang
Keyword(s):  
Water Level ◽  
Real Time ◽  
River Water ◽  
Urban Areas ◽  
Urban River ◽  
Water Levels ◽  
Urban Water ◽  
Short Term ◽  
Forecast Performance ◽  
Flood Season

Water level management is an important part of urban water system management. In flood season, the river should be controlled to ensure the ecological and landscape water level. In non-flood season, the water level should be lowered to ensure smooth drainage. In urban areas, the response of the river water level to rainfall and artificial regulation is relatively rapid and strong. Therefore, building a mathematical model to forecast the short-term trend of urban river water levels can provide a scientific basis for decision makers and is of great significance for the management of urban water systems. With a focus on the high uncertainty of urban river water level prediction, a real-time rolling forecast method for the short-term water levels of urban internal rivers and external rivers was constructed, based on long short-term memory (LSTM). Fuzhou City, China was used as the research area, and the forecast performance of LSTM was analyzed. The results confirm the feasibility of LSTM in real-time rolling forecasting of water levels. The absolute errors at different times in each forecast were compared, and the various characteristics and causes of the errors in the forecast process were analyzed. The forecast performance of LSTM under different rolling intervals and different forecast periods was compared, and the recommended values are provided as a reference for the construction of local operational forecast systems.

Sign in / Sign up

Export Citation Format

Share Document