Lessons from recent

Philippine disasters

Alfredo Mahar Francisco A. LagmayNational Institute of Geological Sciences, University of the

Philippines

U.P. Academic Forum on Climate Change Photo from Boston.com

Dec 2005 Typhoon Quedon

Mindoro Flooding US$ 0.5 million

Feb. 17, 2006 Guinsaugon landslide 1126 dead US$ 2.203 million

GuinsaugonPopulation = 1,857

Nov. 30, 2006 Typhoon Durian 1399 dead US$ 66.4 million

Padang

Bongga

DaragaCamalig

Basud

Guinobatan

June 20, 2008 Typhoon Fenshen 644 dead US$ 135 million

1. Timely and accurate prediction of rainfall

(TRMM and automated rain/river

gauges)

2. Accurate Topography

(Light Detection and Ranging)

Advanced technologies needed for

disaster mitigation

Tropical Rainfall Mapping Mission

• Armed with both a passive microwave

sensor and a space-borne precipitation

radar

• The primary objective of the Tropical

Rainfall Measuring Mission satellite (better

known as TRMM) is to measure rainfall

from space.

NASA SATELLITE GREATLY IMPROVES

ACCURACY OF TROPICAL RAINFALL

FORECASTING

NASA, Jan 12, 2000 by David E. Steitz, Allen Kenitzer, Stephanie Kenitzer

New research shows that adding rainfall data from NASA's Tropical Rainfall Measuring Mission (TRMM) satellite and other meteorological satellites to forecast models can more than triple the accuracy of short-term rainfall forecasts.

These model properties are then used to predict the rainfall for three days into the future, with remarkable success.

TRMM uses

• Alternative and supplement to ground-

based observations for cost-effective flood

prediction in under-gauged regions

• NASA Applied Science Program in

partnership with USAID and African-

RCMRD to implement an operational

water-hazard warning system

• To build disaster management capacity

Latest 3 Hourly Global Rainfall

Latest Week of Global Rainfall

Accumulation

Latest hurricanes and typhoons

observed by the TRMM satellite.

Telemetric rain gauge data sent

directly to NASA ground validation

team via the internet

Designs of UP (CP David)

and Ateneo (MO)

To be put in cell phone

towers and churches.

+ project rain gauge

Hazard map scales

National Scale

• 1:50,000-1:100,000

• Accuracy is low -

Whole river basin

• Broad scale planning for major emergencies

• Members of public are interested in flood risk that applies to them

Local scale

• 1:5,000 to 1:25,000

• Accuracy is high - Cadastral level; Lidar

• Planning of localised emergency response (i.e. evacuation and access routes, road closures)

• Public awareness

Accurate local level,

high resolution

hazard maps is a

key element to effective

disaster preparedness!

2m Resolution

LIDAR DSM

Al Duncan, Geomatic Group, UK

1m Resolution

LIDAR DSM

Al Duncan, Geomatic Group, UK

50cm Resolution

LIDAR DSM

Al Duncan, Geomatic Group, UK

25cm Resolution

LIDAR DSM

Al Duncan, Geomatic Group, UK

Al Duncan, Geomatic Group, UK

Al Duncan, Geomatic Group, UK

Optech Lynx™

Mobile Mapper

Mobile

Terrestrial

LIDAR

Al Duncan, Geomatic Group, UK

Al Duncan, Geomatic Group, UK

United Kingdom Philippines

Al Duncan, Geomatic Group, UK

Integrated spatial data

Flood risk model, 48 hour event

(Model type = 2D, Tuflow model, 1m resolution LIDAR data used)

Al Duncan, Geomatic Group, UK

Modelling Flood Depth

Al Duncan, Geomatic Group, UK

Modelling Flood Velocity

Al Duncan, Geomatic Group, UK

Integrated spatial data

© Crown Copyright. All rights reserved. Environment Agency, 100026380, 2009.

Scenario 6: Fluvial Flood Model – 7 Return Periods

Viewpoint A

X = 542290

Y = 108900

Z = 400m

Direction 346

Integrated spatial data

© Crown Copyright. All rights reserved. Environment Agency, 100026380, 2009.

Scenario 2: Fluvial 1 in 2 year, Tidal 1 in 200 year, Plus Climate Change

Viewpoint A

X = 542290

Y = 108900

Z = 400m

Direction 346

Integrated spatial data

© Crown Copyright. All rights reserved. Environment Agency, 100026380, 2009.

Scenario 1: Fluvial 1 in 2 year, Tidal 1 in 200 year

Viewpoint A

X = 542290

Y = 108900

Z = 400m

Direction 346

Integrated spatial data

© Crown Copyright. All rights reserved. Environment Agency, 100026380, 2009.

Scenario 3: Fluvial 1 in 100 year, MHWS Tide

Viewpoint A

X = 542290

Y = 108900

Z = 400m

Direction 346

Integrated spatial data

© Crown Copyright. All rights reserved. Environment Agency, 100026380, 2009.

Scenario 4: Fluvial 1 in 100 year, MHWS Tide, Plus Climate Change

Viewpoint A

X = 542290

Y = 108900

Z = 400m

Direction 346

Integrated spatial data

© Crown Copyright. All rights reserved. Environment Agency, 100026380, 2009.

Scenario 5: Flood Zones Map – 1 in 1,000 year modelled flood

Viewpoint A

X = 542290

Y = 108900

Z = 400m

Direction 346

GIS enabled website – OS Topographic Map

GIS enabled website – Aerial Photography

GIS enabled website – Historic Flood Map

GIS enabled website – Modelled Flood Map

Investing in knowledge

• Space-based radar, automated rain/river

gauge systems and LIDAR are all readily

available.

• Any serious hazard mitigation program

would have to capitalize on these

technologies.