ANALISIS POTENSI BAHAYA LONGSORAN DI DAS JENEBERANG

LANDSLIDE ON JENEBERANG WATERSHED SOUTH SULAWESI

INDONESIA

MUCHTAR SALAM SOLLE SAYED FAHEEM EQBALI

SUMMER TRAINING COURSE FOR SLOPE LAND DISASTER REDUCTION 2013

MAP OF INDONESIA

JENEBERANG WATERSHED

STUDY AREA Jeneberang Watershed having comparatively complex

ecological characteristics, particularly in terms of geology and landform, river systems, plant species. In addition, a considerable number of activities occur within the catchment including forestry, intensive agriculture and horticulture, rice field,

Satellite Image of Jeneberang Watershed

KOTA

MAKASSAR

Sungai

Jeneberang

Sungai Jenelata

Sungai Malino

Lengkese

Sunggminasa

Dam Bili-Bili

BAWAKARAENG

CALDERA

Punggungan Kawah

Gunung Bawakaraeng

Sand Pocket

Dam No. 5

PAMUKULLU

DAM PROPOSE

Malino

DI Bili-Bili

DI Kampili

DI Bissua

DI Pamukulu

Makassar City

Kendari

Palu

Menad

o

N

PROJECT AREA

Sulawesi Island

SCALE

0

10 Km

5

BILI-BILI DAM Multipurpose Dam: Flood Control, Municipal water,

Irrigation and Hydro power

Bili-Bili Dam is a central core rock fill type dam, 42 to

73 meters above the river bed, with a total crest length

of 1.8 kilometers .

The total storage capacity is 375 million cubic meters

and the effective storage capacity of 346 million cubic

meters. The water was allocated annually for municipal

water 35 million cubic meters, irrigation 270 million

cubic meters and 10 million cubic meters for river

maintenance flow.

Gigantic landslide: Upper reach of Jeneberang Catchment

• Occured on March 26, 2004 • Volume of slide mass: ± 200 million cubic metres • Slide mass thickness: + 200 m • Agriculture Area Buried: 1500 ha • The Dam continuously receives sediment delivered from upper REACH of the catchment

45 km

EXISTING KONDITION OF JENEBERANG RIVER

BILI-BILI DAM

LANDSLIDE ON BAWAKARAENG CALDERA-WALL

Pushed out Debris

Collapse Area

Residual Debris in Caldera

Volume of Sliding Mass (Final)

Elevation Height Area Volume Cumulative

(EL. m) (m) (km2) (mil. m3) (mil. m3)

1800 0.00

1900 100 0.17 8.5 8.5

2000 100 0.29 23.0 31.5

2100 100 0.33 31.0 62.5

2200 100 0.40 36.5 99.0

2300 100 0.35 37.5 136.5

2400 100 0.33 34.0 170.5

2500 100 0.10 21.5 192.0

0 1 2km

Assumed Collapse Area

Source : CTIE

LANDSLIDE MASS 7 km

Pushed out Debris

Profil Memanjang S. Jeneberang

INFRASTRUCTURE DAMAGE

10 causalities, 8 injured and 22 missing (as of 7 April 2004, source Posko Pattiro).

10 houses and one elementary school were buried in debris.

Area (paddy field and residential) buried in debris is estimated at 1,500 ha.

635 cows die near the site after the Disaster.

All village people had evacuated immediately after the disaster to Pattiro and Sicini.

Damage caused by the disaster amounts to Rp. 22.14 billion.

DAMAGES

Damages at Lengkese Village

Evacuation of

Village People

Buried

Houses

Buried Paddy Field

(Parangkeke)

DEBRIS & MUD FLOW

HYDROLOGY

Dry season Rainy season

Water quality

Bridge Pushed Out by Debris Flow

FEB 2006 JAN 2008 MAR 2004

OKT 2009 JAN 2010

APRIL 2012

FEB 2008 JAN 2008

EXISTING LANDSLIDE

Titik Longsoran

Landslide occurred on various landcover/landuse

Longsor pada hutan alam Longsor pada hutan pinus

Longsor pada kebun campuran Longsor pada belukar

Tanah Longsor & Perubahan Morphologi Sungai

Coping challenges to community

1. No central mitigation from Government

1. Lack of resource

2. Geographical extend

2. Residents have always known they can not rely on government, Central or Local

1. Local Government 70Km away from site of disaster

2. Dirt road, difficult access before disaster

Possible solutions to challenges

1. Use of education to enhance communities coping capacity

1. Community based risk mapping

2. Capacity building exercise

3. Evacuation drill

4. School curriculum inclusion for natural hazard

2. Susceptibility mapping

1. Hazard zonation

2. Risk assessment

3. Spatial and land-use planning (to avoid agricultural activity along the river bank)

3. Communication

1. No activity is good activity if not transferred to a language and format community

can understand

The End