Hazard, Vulnerability & Risk

Post on 16-Jan-2016

291 views 0 download

Tags:

description

kulkula khan

Transcript of Hazard, Vulnerability & Risk

Application of GIS

PRESENTED

BY

SEENUM & FAREEN

APPLICATION OF GIS/RSAPPLICATION OF GIS/RS

OIL & MINERAL EXPLORATION (O.G.D.C, Oil companies,)

management of water resources ( AKRSP, WAPDA)

natural hazard mapping (FFC, NESPAK

SOCIO-ECONOMIC SURVEY & MAPPING (S.O.P & Primary education project in NWFP, Baluchistan, Sind, N.As & A.K.)

Educational Institution NCE In Geology, University of Peshawar, GIS Centre Punjab University and Brunal College for distance learning Islamabad/Rawalpindi, Environmental Sciences and Geography Departments in University of Peshawar.

APPLICATION OF GIS/RSAPPLICATION OF GIS/RS

LAND-USE PLANNING AND MANAGEMENT Property Registration & Development Use of parcels during different years (For diff crops) Owner changes & keeping up to date record Developmental plans like Peshawar Master plans Urban Planning and management

Survey of Pakistan, SUPARCO, Peshawar Development Authority, Capital Development Authority, Planning Environment & Development AJK)

hazard: the probability of occurrence of a potentially damaging phenomenon,vulnerability: the degree of loss resulting from the occurrence of the phenomenon

Hazard and risk Hazard and risk assessmentassessment

Monitoring for early warning

Remote Sensing & GIS

• Remote Sensing and Geographical Information Systems (GIS) are widely used for the assessment of natural hazards, especially in Natural Hazard Zonation and Mapping

Definition of a flood.

• A flood is any high stream flow which overtops the natural or artificial banks of a stream.

• A flood is a body of water that inundates land that is in frequently submerged and in doing so causes or threatens to cause damage and loss of life.

• Flooding is a natural and recurring event for a river or stream.

Flooding is a natural hazard

• Potential damaging natural phenomena;

• Occuring with a certain probability;• Within a specific period of time;• In a certain area.

Flood statistics.

http://www.munichre.com/press/press/990315_eng.htm

Reasons for increasing annual flood losses-1• Climatic change;• Changes in land use:

– urbanization;– deforestation;– drainage and engineering works; e.g. canalizations

Reasons for increasing annual flood losses-2• Increasing population levels due to

migration into marginal lands.

TYPES OF FLOODS

• Flash floods;• Single event floods;• Multiple event floods;• Seasonal floods.

Flash floods-1

• An extreme, though short-lived, form of inundation;

• Associated with violent thunderstorms or cloudbursts;

• Storm lasts (usually) < 24 hrs;• Rainfall intensity >>> infiltration capacity;• Runoff rapid, hence • Common in mountaineous and desert

areas.

Single event flood.

• Floods with a single main peak;• Relatively simple hydrograph;

substantially longer duration than flash floods

• Rainfall: several hours or days duration.

Multiple event floods.

• Duration of flooding extends over a periods of several weeks or months;

• Most disastrous type of flooding;

Seasonal flood-1.

• Multiple event flood occuring annually in the wet season on a massive scale;

• Flood extending over several months;• Often disastrous floods

FLOOD CAUSES.

• Climatological:– excessive levels of precipitation; high intensity

and/or long duration;– melting snow or rain falling on melting snow;– melting ice.

• Climatological factor in combination with other factors: e.g causing estuarine floods and sea floods:– wind direction and strength;– intensity of low pressure systems

Example: Flood modeling in BangladeshExample: Flood modeling in Bangladesh

Mississippi, July 1988 and 1993

Flood causes-2.

• Climatological factor in combination with other factors (continu):– tidal stage;– the geometry of the sea basin;– the nature of the coast line.

• Other, only indirectly, if at all, with climatological events:– tsunamis produced by earthquakes;– river ponding behind natural dams caused by

mass movements, glacial advances etc.

Flood causes-2.

• Other, only indirectly, if at all, with climatological events (continu):– failure of natural and man-made levees;– failure of man-made dams;– mass movements entering enclosed or

semi-enclosed waterbodies;– rupture of a glacial lake or release of sub-

glacial water (GLOF);

Floods & use of remote sensing.• Major drawback optical sensors

cannot penetrate cloud;• Therefore Radar has been using which

has the capability to penetrate into clouds.

Remote Sensing for Flood Hazard Studies: applications.

• Mapping spatial distribution of inundated areas;• Mapping spatial distribution of flood effects;• Indirect mapping to make flood susceptibility

maps using flood indicators; • Flood hazard zonation using sequential

imagery and or integrating different types of imagery;

• Damage assessment post flood;• Planning of emergency & relief operations;

Remote Sensing for Flood Hazard Studies: applications.

• Monitoring for early warning;sequential inundation stage mapping;

• Generating DEM’s for modelling etc.;• Combining DEM with areal extent map to

find flood depth map.

Geomorphological effects of the 1993-flood

hills

floodplain

TM images: bands 7, 5, and 3

Missouri River Floodplain, Glasgow, Missouri, USA.

http://edcwww2.cr.usgs.gov/moberly/preflood.gif

Totally inundated floodplain.

Sand deposits, from levee breaches.

Predicting River FloodingThere are three methods:1. Monitoring the progress of a storm in order to

provide a forecast or early warning to those who may be affected by a flood.

2. Using Statistical techniques to predict the frequency & its return period of floods of a given magnitude.

3. Using models & mapping to determine the aerial extent of flood hazard of a given magnitude.

CLIMOGRAPH OF DISTRICT CHARSADDA (Average Climate Between 1960-1990)

0102030405060708090

January

February

March

April

May

June

July

August

September

October

November

DecemberMoths

RAIN

FALL

IN M

M

051015202530354045

TEM

PERA

TURE

IN

OC

Rainfall

Maximum TemperatureMinimum Temperature

Using Statistical Techniques

Based on the records of hydrologic events at a specific locality on the observing river system.

For each year we record one highest flow discharge of the river.

As a result a record of annual maxima over a period of years is taking into consideration.

The longer the available data set, the more valid are the predictions based on the data especially it is very useful for very high frequency floods.

RIVER SWAT AT KALAMFLOOD FREQUENCY RECURRENCE CURVE

18,400

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000

Annual Maximum Discharge (Cusecs)

Re

curr

en

ce In

terv

al (

Ye

ars

)

Example: Flood modeling in BangladeshExample: Flood modeling in Bangladesh

Regional flood hazard:

Based on:NOAA AVHRRGeomorphological mappingMapping historic floods

Relation flooding with GeomorphologyLanduse

Existing Policies for the Reduction of Natural Hazards in Pakistan Non-Intervention Policy

Compensatory Policy

System Management Policy

Corrective or Engineering Protection Policy

More stress in Pakistan is on post-disaster activities

Pre-Disaster Activities are either

missing or less

THANKS TO ALL

• SEENUM AMAN• FAREEN QAZI