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.

scholarly journals Operation Techniques and Hydrological Applications of X-band Dual-polarization Radar for Monitoring Flash Flood in Metropolitan Area

2020 ◽  
Vol 20 (2) ◽  
pp. 25-33
Author(s):  
Jungsoo Yoon ◽  
Seokhwan Hwang ◽  
Dong-Ryul Lee ◽  
Narae Kang
Keyword(s):  
Metropolitan Area ◽  
Urban Areas ◽  
Flash Flood ◽  
Rainfall Data ◽  
Dual Polarization ◽  
Information Platform ◽  
Building Technology ◽  
X Band ◽  
Operation Techniques ◽  
Hydrological Applications

Radar is useful for monitoring flash flood in urban areas because it provides rainfall data with high spatial and temporal resolution for a wide area. In 2014, the Korea Institute of Civil Engineering and Building Technology introduced the first X-band dual-polarization radar in Korea and has subsequently been researching on flash floods in the metropolitan area using the rainfall data. Considering the various advantages of X-band dual-polarization radar, the Water Hazard Information Platform in Korea introduced two X-band dual-polarization radars (KRU and YSU radars) into the metropolitan area, in 2017. This study described the characteristics of KRU and YSU radars, their observation strategies, and quality control techniques. Moreover, we also assessed the hydrological applications of the X-band dual-polarization radars in the metropolitan area by analyzing three years of rainfall data from 2017 to 2019.

scholarly journals Coupling X-band dual-polarized mini-radars and hydro-meteorological forecast models: the HYDRORAD project

2013 ◽  
Vol 13 (5) ◽  
pp. 1229-1241 ◽  
Author(s):  
E. Picciotti ◽  
F. S. Marzano ◽  
E. N. Anagnostou ◽  
J. Kalogiros ◽  
Y. Fessas ◽  
...  
Keyword(s):  
Decision Support ◽  
High Frequency ◽  
Weather Radar ◽  
Decision Support Tool ◽  
Dual Polarization ◽  
Radar Observations ◽  
Support Tool ◽  
Radar Network ◽  
X Band ◽  
Modelling System

Abstract. Hydro-meteorological hazards like convective outbreaks leading to torrential rain and floods are among the most critical environmental issues world-wide. In that context weather radar observations have proven to be very useful in providing information on the spatial distribution of rainfall that can support early warning of floods. However, quantitative precipitation estimation by radar is subjected to many limitations and uncertainties. The use of dual-polarization at high frequency (i.e. X-band) has proven particularly useful for mitigating some of the limitation of operational systems, by exploiting the benefit of easiness to transport and deploy and the high spatial and temporal resolution achievable at small antenna sizes. New developments on X-band dual-polarization technology in recent years have received the interest of scientific and operational communities in these systems. New enterprises are focusing on the advancement of cost-efficient mini-radar network technology, based on high-frequency (mainly X-band) and low-power weather radar systems for weather monitoring and hydro-meteorological forecasting. Within the above context, the main objective of the HYDRORAD project was the development of an innovative \\mbox{integrated} decision support tool for weather monitoring and hydro-meteorological applications. The integrated system tool is based on a polarimetric X-band mini-radar network which is the core of the decision support tool, a novel radar products generator and a hydro-meteorological forecast modelling system that ingests mini-radar rainfall products to forecast precipitation and floods. The radar products generator includes algorithms for attenuation correction, hydrometeor classification, a vertical profile reflectivity correction, a new polarimetric rainfall estimators developed for mini-radar observations, and short-term nowcasting of convective cells. The hydro-meteorological modelling system includes the Mesoscale Model 5 (MM5) and the Army Corps of Engineers Hydrologic Engineering Center hydrologic and hydraulic modelling chain. The characteristics of this tool make it ideal to support flood monitoring and forecasting within urban environment and small-scale basins. Preliminary results, carried out during a field campaign in Moldova, showed that the mini-radar based hydro-meteorological forecasting system can constitute a suitable solution for local flood warning and civil flood protection applications.

Dual-polarization X-band phased array weather radar: Technology update

2014 ◽  
Author(s):  
Peter R. Drake ◽  
Jacqueline Bourgeois ◽  
Anthony P. Hopf ◽  
Francis Lok ◽  
David McLaughlin
Keyword(s):  
Phased Array ◽  
Weather Radar ◽  
Dual Polarization ◽  
X Band

scholarly journals Quality Assessment of Weather Radar Wind Profiles during Bird Migration

2008 ◽  
Vol 25 (12) ◽  
pp. 2188-2198 ◽  
Author(s):  
Iwan Holleman ◽  
Hans van Gasteren ◽  
Willem Bouten
Keyword(s):  
Bird Migration ◽  
Doppler Radar ◽  
Weather Prediction ◽  
Weather Radar ◽  
Numerical Weather Prediction Model ◽  
Limited Area ◽  
Migration Direction ◽  
X Band ◽  
Performance Statistics ◽  
Wind Profiles

Abstract Wind profiles from an operational C-band Doppler radar have been combined with data from a bird tracking radar to assess the wind profile quality during bird migration. The weather radar wind profiles (WRWPs) are retrieved using the well-known volume velocity processing (VVP) technique. The X-band bird radar performed range–height scans perpendicular to the main migration direction and bird densities were deduced by counting and normalizing the observed echoes. It is found that the radial velocity standard deviation (σr) obtained from the VVP retrieval is a skillful indicator of bird migration. Using a threshold of 2 m s−1 on σr, more than 93% of the bird-contaminated wind vectors are rejected while over 70% of the true wind vectors are accepted correctly. For high bird migration densities the raw weather radar wind vectors have a positive speed bias of 8.6 ± 3.8 m s−1, while the quality-controlled wind vectors have a negligible speed bias. From the performance statistics against a limited area numerical weather prediction model, it is concluded that all (significant) bird contamination is removed and that high-quality weather radar wind profiles can be obtained, even during the bird migration season.

Performance evaluation of high-resolution rainfall estimation by X-band dual-polarization radar for flash flood applications in mountainous basins

2010 ◽  
Vol 394 (1-2) ◽  
pp. 4-16 ◽  
Author(s):  
Marios N. Anagnostou ◽  
John Kalogiros ◽  
Emmanouil N. Anagnostou ◽  
Michele Tarolli ◽  
Anastasios Papadopoulos ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
High Resolution ◽  
Flash Flood ◽  
Dual Polarization ◽  
Rainfall Estimation ◽  
X Band
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