hydrological forecasting: application, uncertainty, estimation, data assimilation and decision...

Hydrological forecasting: application, uncertainty, estimation, data assimilation and Hydrological forecasting: application, uncertainty, estimation, data assimilation and decision makingdecision making

EGU – Wien, 7th april 2011EGU – Wien, 7th april 2011

The Po flood management in Italy:guidelines and methodologies

G.Ricciardi[3], L.Casicci [1], L.Fortunato[1], S.Pecora[3], N.Rebora[2], M.Vergnani [1]

[1] AIPO Interregional Agency for the Po river

[2] CIMA Research Foundation, Italy

[3] ARPA EMR Environmental Agency of Emilia Romagna Region



Summary

Introduction

Scheme

Example

Actual development

Further steps



Introduction

An operative forecasting and modeling system for hydrological cycle and extreme events is adopted on the Po river

It is composed of three modelling chains simulating hy/hy behaviour feeded by observations and forecasting meteorological data

A methodology for utilization of system output is needed expecially to compare system capabilities with resources and needs and finally choose the best operational procedures

This methodologic scheme is here presented

It is based on a State approach.

State changes are defined according to observed and predicted values of hydrological parameters and traveling times of river sections

Analysis of input/output data and of forecast performances are taken into account



Scheme

State changes

Flow for each state

Details

Intersection reality - information



Forecasted event on secondary reaches

Guided by observation

Guided by run on observation

Forecasted event on the main reach

State 1 (forecast)

State 2 (surveillance )

State 3 (monitoring)

Imminent event on the main reach

End of event

Not confirmed event

State changes (information layer)

Secondary reaches:Response time less than 12 h

Guided by deterministic forecast



1. Meteorological Forecast analysis

2. Deterministic Hydrological Forecast (on a reach list)

3. Probabilistic HF analysis (only if an event is forecasted)

Go on with State 1: no Forecasted Events

Go to State 2: FE on the main reach

Go to State 3: FE on secondary reaches

Step flow in State 1 (Forecast)



1. Deterministic Hydrological forecast

2. Observed simulation HF ( if an event is forecasted)

Go back to State 1: no event is forecasted in Step 1

Go back to Step 1: no event is forecasted in Step 2

Go to State 3: an event is forecasted in Step 2

Step flow in State 2 (Surveillance)



1. Observed level analysis

2. Unbiased observed simulation Hydrologic Forecast (no Threshold Exceedings in Step 1)

3. Deterministic HF (no TE in Step 2)

Continuous monitoring: TE in Step 1 Real Time notifications

High frequency monitoring:

TE in Step 2 and low frequency monitoring is on

Low frequency monitoring:

TE in Step 3 and monitoring on shortest response time reaches (e.g. 12h) is off

Go back to State 1: no more TE in Step 3 (end of event)

Step flow in State 3 (Monitoring)



Saturation degree of sub basins (AMC)

Forecasted and observed total rainfall on sub basins (LAM runs)

(aggregation on RT)

Localization of critical reaches (scenarios)

Details: Meteorological forecast analysis



o HF based on observed precipitation up to T0(now) + forecasted precipitation from T0 to LAM lead time

(e.g. 72 hour)

o HF based on observed precipitation up to T0 + null precipitation from T0 to hydrological lead time

(Observed simulation HF)

Details: Deterministic Hydrological forecast analysis



Details: Deterministic Hydrological forecast analysis



Details: Probabilistic Hydrological forecast analysis

Bollettino di previsione, vigilanza e monitoraggio per il bacino del fiume PoBollettino di previsione, vigilanza e monitoraggio per il bacino del fiume PoParma, 15 luglio 2010Parma, 15 luglio 2010

Servizio Servizio IdroMeteoClimaIdroMeteoClima

23 November 2002

Observed simulation forecast

Deterministic forecast – COSMO I7

Probabilistic forecast – COSMO LEPS

Forecast Surveillance

State 1 Hydrologic hydraulic forecast analysis - PIACENZA

Time (hour)



24 November 2002

Hydrologic forecast analysis - PIACENZA




State 2

Time (hour)Surveillance Surveillance



26 November 2002

Hydrologic forecast analysis - PIACENZA




State 3

Time (hour)

Monitoring Monitoring



Example -I



Example - II Piacenza: sample analysis of maximum levels



Example - III

Observed

Peak water level: 6.14 m

Peak discharge: 5.400 mc/s

Date of peak: 18/03/2011 5:00 a.m.

Time at L1 exceeding: 17/03/2011 4:00 a.m. (+100 hour)

Time at L2 exceeding: 17/03/2011 9:00 p.m. (+117 hour)

No L3 exceeding

Duration of L1 exceeding: 40 h

Duration of L2 exceeding: 12 h



Actual development -I Methodology

• Layout of information scheme

• Analysis and computations

• Terminology/simbology

• End users

• Frequency

• Equipments, human resources, activities - User manual



Actual development- II Information import Synoptic - Civil Protection - Regional Centres reports

System status checking Updating the systemAnomalies

Analysis P/Q_WL(hydrologic state), system performances, post processing Briefing

Condivision National Civil Protecion, Agency for Po river, Regional Centres

Information diffusion

Information storing



Actual development- III Procedure, scheme, information and analysis, terminology and

symbology, time of emission and the other elements are different

for each state

They are intended to supply both useful information, with agreed

uncertainty, and the best perception of what is occurring,

balancing execution times and lead times required by decision

makers, reducing missed alarms and false alarms

Knowledge and awareness can be increased across the different

states giving more and more information and analysis, raising

diffusion frequency and giving diffusion advance



Further steps

Applications and further developments of the proposed methodology are related to:

• additions of modeling components to the operative system

• next operational steps (operational procedures, prototype definition and testing,

errors recording and corrective actions)

In the second phase coordination and information exchange actions will be

furthermore focused.



Thank you for your attention!



• Observed levels (gards)

• Rating curve

• Hydraulic model

• Hydrological model

• Observed precipitation

• Forecast precipitation

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