ROFFGROFFG

Romania Flash Flood Guidance SystemRomania Flash Flood Guidance System

The Romania Flash Flood The Romania Flash Flood Guidance System is an Guidance System is an

adaptation of the HRC Flash adaptation of the HRC Flash Flood Guidance System used in Flood Guidance System used in various regions of the world.various regions of the world.

The ROFFG is designed to provide flash flood The ROFFG is designed to provide flash flood guidance information on a small basin scale guidance information on a small basin scale

across the entire country of Romaniaacross the entire country of Romania

The primary purpose of the ROFFG system is The primary purpose of the ROFFG system is to provide real time informational guidance to provide real time informational guidance

products pertaining to the imminence of products pertaining to the imminence of potential small-scale flash floodingpotential small-scale flash flooding

The ROFFG system ingests The ROFFG system ingests real-time radarreal-time radar and and gauge precipitationgauge precipitation data on an hourly basis and data on an hourly basis and

other meteorological information (e.g. other meteorological information (e.g. temperature, snow information during winter temperature, snow information during winter months), and produces flash-flood-occurrence months), and produces flash-flood-occurrence

diagnostic indices over each of 8851 small diagnostic indices over each of 8851 small basins in Romania (with an average area of basins in Romania (with an average area of

approximately 30 square kilometers) approximately 30 square kilometers)

The ROFFG system includes two cooperating The ROFFG system includes two cooperating servers that work in tandem to provide a full servers that work in tandem to provide a full

array of ROFFG operational acquisition, array of ROFFG operational acquisition, processing and dissemination featuresprocessing and dissemination features

ROFFG Computation ServerROFFG Computation Server• Collect and process real-time data using various models to Collect and process real-time data using various models to

produce FFGproduce FFG

ROFFG Dissemination ServerROFFG Dissemination Server• Provide secure WWW access to data products for all Provide secure WWW access to data products for all

participating agencies participating agencies

Products produced by the ROFFG system Products produced by the ROFFG system include the followinginclude the following

RADARRADAR MERGED MAPMERGED MAP GMAP (Gauge MAP)GMAP (Gauge MAP) ASM (Average Soil Moisture)ASM (Average Soil Moisture) FFG (Flash Flood Guidance)FFG (Flash Flood Guidance) FFT (Flash Flood Threat)FFT (Flash Flood Threat)

RADARRADAR

Un-biased Un-biased corrected corrected rainfall for 1, 3, rainfall for 1, 3, 6 and 24 hour 6 and 24 hour accumulation accumulation (based on (based on radar rainfall radar rainfall estimates from estimates from the Romania the Romania radar network) radar network) – only images– only images

The Romanian radar networkThe Romanian radar network

Doppler radars generate an impressive suite of more than 70 products, including both base and derived products.

Available products for flash flood issues:

Base products: R (reflectivity), V (Velocity), W (spectrum Width);

Elevations:=0.5, 1.5, 2.4, 3.4, etc;

Reflectivity range: 5 to >75 dBZ;

Approx. 6 minutes between scans;

Polar products: 1 degree, 1 km;

Romania has fully integrated three types of radar equipment into one integrated network (SIMIN).

The SIMIN (National Integrated Meteorological System) and DESWAT (Destructive Waters Abatement and Control of Water Disasters), based on 9 Doppler radars (5 new WSR-98D S-band and 4 Doppler radars in C band -EEC and Gematronik), 8 lightning detectors, meteorological and hydrological automatic stations, meteorological and hydrological models, warning dissemination systems.

MERGED MAPMERGED MAP Mean areal Mean areal

precipitation precipitation for each basin for each basin for 1, 3, 6 and for 1, 3, 6 and 24 hour 24 hour accumulations accumulations based on bias based on bias corrected corrected radar rainfall radar rainfall estimates estimates and/or in-situ and/or in-situ gauge gauge estimates estimates

- text table - text table and imagesand images

GMAP (GAUGE MAP)GMAP (GAUGE MAP)

Mean areal Mean areal precipitation precipitation for each basin for each basin for 1 hour for 1 hour (only) (only) accumulation accumulation based on based on available available gauge datagauge data

- text table - text table and imageand image

ASM (Average Soil Moisture) ASM (Average Soil Moisture)

Average Average soil water soil water content for content for each basin each basin (fraction of (fraction of saturation saturation for the for the upper soil upper soil layer , layer , nominally nominally 20 cm)20 cm)

- text table - text table and imageand image

FFG (Flash Flood Guidance)FFG (Flash Flood Guidance)

Flash flood Flash flood guidance guidance for each for each small basin small basin for 1, 3 and for 1, 3 and 6 hours6 hours

- text - text tables and tables and images images

Flash flood guidance is the amount of rainfall for a Flash flood guidance is the amount of rainfall for a given duration over a small basin needed to create given duration over a small basin needed to create minor flooding (minor flooding (bankfullbankfull) conditions at the outlet of ) conditions at the outlet of the basin. So, FFG is an index that indicates how the basin. So, FFG is an index that indicates how much rainfall is needed to cause minimal flooding in much rainfall is needed to cause minimal flooding in a basin.a basin.

BankfullBankfull flow is flow is employed as the flow employed as the flow associated with associated with floodingflooding

FFT (Flash Flood Threat)FFT (Flash Flood Threat) FFT is the amount of FFT is the amount of

rainfall of a given rainfall of a given duration in excess of duration in excess of the corresponding FFG the corresponding FFG value.value.

The FFT when used The FFT when used with existing or with existing or forecast rainfall is an forecast rainfall is an index that provides an index that provides an indication of areas indication of areas where flooding is where flooding is imminent or occurring imminent or occurring and where immediate and where immediate action is or will be action is or will be shortly neededshortly needed

- text table and images- text table and images

The FFG and FFT guidance provided by the The FFG and FFT guidance provided by the ROFFG system is not applicable for urban, ROFFG system is not applicable for urban,

household or building basement or other flooding household or building basement or other flooding not associated with a streamnot associated with a stream

The FFG and FFT products are considered The FFG and FFT products are considered inappropriate for dates between November 15inappropriate for dates between November 15thth

and March 1and March 1stst

During the winter, the ROFFG still receives data in During the winter, the ROFFG still receives data in order to update the soil moisture.order to update the soil moisture.

..

The Flash Flood Guidance System is not a The Flash Flood Guidance System is not a predictive system in itself, rather it is a predictive system in itself, rather it is a

diagnostic system for flash floods that the diagnostic system for flash floods that the forecaster can use with forecaster can use with forecastsforecasts or or nowcastsnowcasts of precipitation to produce of precipitation to produce

forecasts and ultimately warnings for flash forecasts and ultimately warnings for flash floodsfloods