use of gis in managing geoscience datangis.mygeoportal.gov.my/sites/default/files/media/ngis5/kertas...

MINGEOSIS EIS

mailto:[email protected]

1. Introduction

2. GIS Application in

a. Geological Terrain Mapping

b. Geohazard Mapping

3. Conclusions

1. JMG as Custodian

for mineral and

geoscience data

& information

2. GIS has been

extensively and

effectively used to

manage and

analyse the large

amount of data

3. Geoscience data

include geological,

geochemical,

geophysical,

hydrogeological and

engineering

geological data

Relict os a landslide

4. These data together with other geospatial information such as topography, remote sensing, land-use and rainfall distribution data are being processed and analysed to generate various derivation of informative maps

5. The informative maps produced, such as groundwater potential, mineral potential, construction suitability and landslide hazard and risk maps, are very useful for land-use and development planning purposes

6. This paper highlights some examples where GIS has been utilized in managing and processing geoscience data, particularly for geohazard mapping

Zen Garden

SK Pekan Kundasang

Mount

Kinabalu

Heritage

Resort &

SPA

MINGEOSIS

MINGEOSIS

MINGEOGIS

MAPGIS// EXPLOGIS// MINGIS// HYDROGIS// ENGEOGIS

MINGEODAT

SPATIAL DATA TOPO GEOLOGY

DATABASE

APPLICATIONS

Information

Reports

Map Reports

Cartographic maps

Thematic maps

IM Dat ENERGY Dat

METAL Dat

MINE Dat

QUARRY Dat

GEOCHEM Dat

HYDRO Dat

ENGEO Dat

1. Introduction




3. Conclusions

2005

2011

Geological terrain mapping has been employed as an effective tool in development planning and in the management of geohazards in an area.

Basic information were collected in the field, involving geology, topography and landform as well as geodynamic features such as landslides and severe erosion.

Four attributes for Terrain Classification: slope gradient

morphology

activity and

erosion & instability

GIS was used to collate and analyse these data to generate various derivative thematic maps

Generated thematic maps:

1) Terrain Classification map

2) Landform map

3) Erosion map

4) Physical Constraints map

5) Engineering geological map

6) Construction Suitability map

Geology map

Slope Gradient Map

Terrain Classification Map

Landform Map

Erosion Map

Physical Constraints

Map

C

on

stru

ctio

n S

uit

abili

ty

Map

Class > V Characteristics

CLASS I CLASS II CLASS III CLASS IV

Geotechnical

Limitations

LOW MODERATE HIGH EXTREME

Suitability for

Development

HIGH MODERATE LOW PROBABLY

UNSUITABLE

Engineering Cost

for Development

LOW NORMAL HIGH VERY HIGH

Intensity of Site

Investigation

Required

NORMAL NORMAL INTENSIVE VERY

INTENSIVE

CLASS I – Low

Geotechnical Limitations

a) Insitu terrain: < 5o gradients

b) Cut slope: < 5o gradients

CLASS II – Moderate


a) Hillcrest or Ridge

b) Insitu Terrain: >15o; <25o slope gradients

with no evidence of erosion or instability

c) Insitu Terrain <15o slope gradients with

evidence of erosion and instability

d) Insitu Terrain <15o slope gradients

comprises of colluvium or sensitive

geological materials

CLASS III – High Geotechnical Limitations

CLASS IV – Extreme Geotechnical

Limitations

CLASS I – Low Geotechnical Limitations

CLASS II – Moderate Geotechnical

Limitations

CLASS III – High


a) Insitu Terrain 25 – 35o slope gradients with

no evidence of erosion or instability

b) Insitu Terrain 15 – 25o slope gradients with

no evidence of moderate to severe gully

erosion and instability

c) Insitu Terrain <15o slope gradients


geological materials with instability

d) Insitu Terrain 15 – 25o slope gradients



e) Limestone, swampy, peat and mined-out

areas

CLASS IV – Extreme Geotechnical

Limitations

CLASS I – Low Geotechnical Limitations

CLASS II – Moderate Geotechnical

Limitations

CLASS III – High Geotechnical

Limitations

CLASS IV – Extreme


a) Insitu Terrain >35o slope gradients, with no

evidence of erosion or instability

b) Insitu Terrain 25 – 35o slope gradients with

evidence of moderate to severe gully

erosion and instability

c) Insitu Terrain 25 – 35o slope gradients,



d) Insitu Terrain 15 – 25o slope gradients,


geological materials with instability

1. Introduction




3. Conclusions

2005

2011

Landform Map

Erosion Map Physical Constraints Map

Construction Suitability Map

Engineering Geology Map

(Integrated with other agencies)

Slope Gradient Map

Geological Terrain and

Landslide Hazard

Mapping in Kundasang

area, Sabah

Monitoring Active Fault & Surface Motion

Semuga Foto Ini Menjadi PERINGATAN Kepada Kita Semua

2005 >

^ Apr 2011

< Dis 2011

CONSTRUCTION

SUITABILITY MAP

Our Approach: use

the four attributes

from the geological

terrain mapping plus

a 5th attribute,

namely vegetation

cover and water

seepage.

Generate a landslide

hazard map with four

classes (Chow & Zakaria 2002)

Class

Score Rating Hazards

1 LOW Landslide

Hazard <0.25

2

MODERATE

Landslide

Hazard

0.26 – 0.50

3

HIGH

Landslide

Hazard

0.51 – 0.75

4

VERY HIGH

Landslide

Hazard

>0.76

Landslide risk maps

quantify the

vulnerability of an

area and refer to

the consequences

of the failure on

human activities.

The consequential

effect of landslide

defines the degree

of risk in an area.

Landslide risk scores

are then calculated

using the standard

equation. (Risk = Hazard x Consequence)

Kundasang

Type of RISK Land Use / Premises Weightage

Risk of lives

Critical buildings affected Normal buildings affected Isolated buildings affected Very busy trunk road Busy trunk road

Moderately used trunk road Seldom use trunk road

20 10 5 10 7

5 1

Economic Losses

Damage to farm/park Business area Only access to housing area Temporary diversion > 1 day

Temporary diversion <1 day Alternative road > 5km Alternative road <5km

3 10 6 3

0 3 0

Public Utilities Affected Not affected

10 0

Proximity of building

to suspected

landslide

Very close Close Possibly affected Unlikely to be affected Not affected

10 5 2 0 0

Rating Total Score

LOW Risk

<12.5

MODERATE Risk

12.5 – 25.0

HIGH Risk

26.0 – 35.0

VERY HIGH Risk

>35.0

Aft

er

Ch

ow

an

d Z

aka

ria

, 20

02

1. Introduction




3. Conclusions

1. GIS application has been effectively used in analysing and managing geoscience data to produced useful informative maps for landuse and development planning purposes.

2. The GIS approach in geohazards mapping by JMG involved statistical analysis and a heuristic method to establish the hazard ratings of a study area.

3.The geohazards maps produced served as

a guideline to manage and reduce risk to

properties destruction and human casualty.

use of gis in managing geoscience datangis.mygeoportal.gov.my/sites/default/files/media/ngis5/kertas...

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