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EXTREME RAINFALL DETECTION SYSTEM
BASED ON
BOTH NEAR REAL-TIME AND FORECAST
RAINFALL MEASUREMENTS
Paola Mazzoglio
ITHACA, Torino, Italy
paola.mazzoglio@ithaca.polito.it
ERDS
(EXTREME RAINFALL DETECTION SYSTEM - erds.ithacaweb.org)
MONITORING AND FORECASTING
OF EXCEPTIONAL RAINFALL EVENTS
IDENTIFICATION
OF HYDROLOGICAL EVENTS
HURRICANES - CYCLONES
TROPICAL STORMS
FLOODS - FLASH FLOODS
CONVECTIVE STORMS
WEB GIS APPLICATION
OPEN SOURCE ENVIRONMENT
NEAR REAL-TIME RAINFALL MONITORING
(PREVIOUS VERSION OF ERDS)
INPUT
NASA TRMM TMPA 3-hourly data
RAINFALL AMOUNT EVALUATION
ALERTS EVALUATION
IDENTIFICATION OF AREAS POTENTIALLY AFFECTED BY HYDROLOGICAL DISASTERS
NEAR REAL-TIME RAINFALL MONITORING
(PREVIOUS VERSION OF ERDS)
INPUT
NASA TRMM TMPA 3-hourly data
RAINFALL AMOUNT EVALUATION
ALERTS EVALUATION
IDENTIFICATION OF AREAS POTENTIALLY AFFECTED BY HYDROLOGICAL DISASTERS
?
NEW INPUT DATA
NASA GPM (Global Precipitation Measurement)
IMERG (Integrated Multi-satellite Retrievals for GPM) products
TEMPORAL COVERAGE
from 12 March 2014 to nowadays
TEMPORAL RESOLUTION
30 minutes
SPATIAL COVERAGE
60° N – 60° S
SPATIAL RESOLUTION
0,1° x 0,1°
NEW INPUT DATA
THREE DIFFERENT VERSIONS OF HALF-HO URLY DATA
early run (4 hours latency)
late run (12 hours latency)
final run (3 months latency)
NASA GPM (Global Precipitation Measurement)
IMERG (Integrated Multi-satellite Retrievals for GPM) products
NEW INPUT DATA
THREE DIFFERENT VERSIONS OF HALF-HO URLY DATA
early run (4 hours latency)
late run (12 hours latency)
final run (3 months latency)
near real-time flood risk
monitoring applications
NASA GPM (Global Precipitation Measurement)
IMERG (Integrated Multi-satellite Retrievals for GPM) products
IMERG PRODUCT ACCURACY EVALUATION
DIFFERENT CLIMATIC ZONES
(50 LOCATIONS)
12 March 2014 – 30 April 2017
GPM IMERG HALF-HO URLY
EARLY/LATE
PRODUCT
RAIN GAUGE
DATA
IMERG PRODUCT ACCURACY EVALUATION
( ) ( )
[ ]
∑
=
−=
n
1t
GAUGESAT
tRtR
n
1
BIAS
( ) ( )
[ ]
∑
=
−=
n
1t
GAUGESAT
tRtR
n
1
MAE
IMERG PRODUCT ACCURACY EVALUATION
RAIN GAUGE
= 0 mm/hr > 0 mm/hr
SATELLITE
= 0
mm/hr
CORRECT
NEGATIVES
(A)
MISSES
(B)
ESTIMATED
NON
EVENTS
> 0
mm/hr
FALSE
ALARMS
(C)
HITS
(D)
ESTIMATED
EVENTS
OBSERVED
NON
EVENTS
OBSERVED
EVENTS
IMERG PRODUCT ACCURACY EVALUATION
RAIN GAUGE
= 0 mm/hr > 0 mm/hr
SATELLITE
= 0
mm/hr
CORRECT
NEGATIVES
(A)
MISSES
(B)
ESTIMATED
NON
EVENTS
> 0
mm/hr
FALSE
ALARMS
(C)
HITS
(D)
ESTIMATED
EVENTS
OBSERVED
NON
EVENTS
OBSERVED
EVENTS
ALARMS FALSE HITS
ALARMS FALSE
FAR +
=
IMERG PRODUCT ACCURACY EVALUATION
RAIN GAUGE
= 0 mm/hr > 0 mm/hr
SATELLITE
= 0
mm/hr
CORRECT
NEGATIVES
(A)
MISSES
(B)
ESTIMATED
NON
EVENTS
> 0
mm/hr
FALSE
ALARMS
(C)
HITS
(D)
ESTIMATED
EVENTS
OBSERVED
NON
EVENTS
OBSERVED
EVENTS
MISSESHITS
HITS
POD +
=
IMERG PRODUCT ACCURACY EVALUATION
NO SIGNIFICANT ACCURACY
INCREASE ASSOCIATED TO
THE USE OF LATE DATA
< 12 HOURS
HIGH VALUE OF BIAS, MAE, FAR
POD NOT ACCEPTABLE
EXTREME RAINFALL DETECTION
(NEW METHODOLOGY)
85 COUNTRIES ANALYZED
63 COUNTRIES WITH AT LEAST 1 HYDROLOGICAL DISASTER
22 COUNTRIES WITHOUT HYDROLOGICAL DISASTER
AGGREGATION INTERVALS
12h – 24h – 48h – 72h – 96 h
EMDAT
RELIEFWEB
FLOODLIST
211
DISASTERS
EXTREME RAINFALL DETECTION
(NEW METHODOLOGY)
THRESHOLD
Δt
ACCUMULATED
PRECIPITATION
ALERT
AMOUNT OF
PRECIPITATION NEEDED
TO TRIGGER A FLOOD
EVENT INDUCED BY
EXTREME RAINFALL
EXTREME RAINFALL DETECTION
24 HOURS AGGREGATION INTERVAL
% OF MEAN
ANNUAL
PRECIPITATION
LOWER AND
UPPER BOUND
[mm] ID EVENTS FALSE ALARMS
ID EVENTS
… …
8% 120 - 210
9% 100 - 190
9% 100 - 210
9% 100 - 230
9% 100 - 250
9% 100 - 300
9% 100 - 350
9% 100 - 400
… …
… …
EXTREME RAINFALL DETECTION
24 HOURS AGGREGATION INTERVAL
% OF MEAN
ANNUAL
PRECIPITATION
LOWER AND
UPPER BOUND
[mm] ID EVENTS FALSE ALARMS
ID EVENTS
… …
8% 120 - 210
9% 100 - 190
9% 100 - 210
9% 100 - 230
9% 100 - 250
9% 100 - 300
9% 100 - 350
9% 100 - 400
… …
… …
MEAN ANNUAL PRECIPITATION
CALCULATED USING 10 YEARS OF GPCC MONTHLY MONITORING PRODUCTS
EXTREME RAINFALL DETECTION
24 HOURS AGGREGATION INTERVAL
% OF MEAN
ANNUAL
PRECIPITATION
LOWER AND
UPPER BOUND
[mm] ID EVENTS FALSE ALARMS
ID EVENTS
… … … …
8% 120 - 210 137 22,96
9% 100 - 190 140 26,28
9% 100 - 210 140 25,21
9% 100 - 230 137 25,53
9% 100 - 250 137 25,31
9% 100 - 300 136 25,36
9% 100 - 350 136 25,35
9% 100 - 400 136 25,35
… … … …
… … … …
ERDS – CURRENT VERSION
THE OUTCOMES OF THIS ANALYSIS SUPPORTED THE DEVELOPMENT OF THE
UPDATED VERSION OF ITHACA EXTREME RAINFALL DETECTION SYSTEM (ERDS)
erds.ithacaweb.org
ERDS – CURRENT VERSION
EXTREME RAINFALL DETECTION SYSTEM - ERDS
erds.ithacaweb.org
GPM IMERG EARLY RUN DATA
NEAR REAL-TIME
CUMULATED RAINFALL
12 hr – 24 hr – 48 hr – 72 hr – 96 hr
ERDS – CURRENT VERSION
EXTREME RAINFALL DETECTION SYSTEM - ERDS
erds.ithacaweb.org
GPM IMERG EARLY RUN DATA
NEAR REAL-TIME
CUMULATED RAINFALL
12 hr – 24 hr – 48 hr – 72 hr – 96 hr
NEAR REAL-TIME ALERTS
12 hr – 24 hr – 48 hr – 72 hr – 96 hr
IMPROVEMENTS
RESOLUTION
ERDS - PREVIOUS VERSION ERDS – CURRENT VERSION
ALERTS PROVIDED
EVERY 3 HOURS
ALERTS PROVIDED
EVERY HOUR
ALERTS EVALUATED WITH A
0,25° x 0,25°
SPATIAL RESOLUTION
ALERTS EVALUATED WITH A
0,1° x 0,1°
SPATIAL RESOLUTION
50° N – 50° S
SPATIAL COVERAGE
60° N – 60° S
SPATIAL COVERAGE
IMPROVEMENTS
THRESHOLD METHODOLOGY
ERDS - PREVIOUS VERSION ERDS - CURRENT VERSION
ONLY 1 THRESHOLD VALUE FOR EVERY
AGGREGATION INTERVAL, MULTIPLIED BY A MASK
OF COEFFICIENTS DEPENDENT ON KOPPEN
CLIMATE CLASSIFICATION
EVERY AGGREGATION INTERVAL
HAS A THRESHOLDS MASK CHARACTERIZED
BY A 1° X 1° SPATIAL RESOLUTION
IMPROVEMENTS
PREVIOUS THRESHOLD
METHODOLOGY
APPLIED AT GPM DATA
CURRENT THRESHOLD
METHODOLOGY
APPLIED AT GPM DATA
12 HOURS AGGREGATION INTERVAL - 150
24 HOURS AGGREGATION INTERVAL 131 137
48 HOURS AGGREGATION INTERVAL 85 120
72 HOURS AGGREGATION INTERVAL 48 112
96 HOURS AGGREGATION INTERVAL 39 118
TOTAL NUMBER OF IDENTIFIED EVENTS
(211 DISASTERS ANALYZED) 135 162
% OF IDENTIFIED EVENTS
(211 DISASTERS ANALYZED) 64 % 77 %
HIGHER NUMBER OF IDENTIFIED EVENTS
LOWER NUMBER OF FALSE ALARMS
NEXT STEPS
RESEARCH OF A FORECAST RAINFALL ESTIMATION
NOAA - GFS (Global Forecast System) deterministic weather prediction model with
0,25° spatial resolution and worldwide coverage
DEVELOPMENT OF A THRESHOLD METHODOLOGY CALIBRATED ON THE FORECAST
RAINFALL ESTIMATION
WORK IN PROGRESS
EVALUATION OF AFFECTED POPULATION
WORK IN PROGRESS
MAPPING ACTIVE CYCLONES TRACKS
WORK IN PROGRESS
FLOODED AREAS EVALUATION
ADDITIONAL INFO ON…
@ ithaca_erds
EXTREME RAINFALL
DETECTION SYSTEM
ERDS
erds.ithacaweb.org
paola.mazzoglio@ithaca.polito.it