HIDROGEOLOGI UMUM (GL-3081)

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HIDROGEOLOGI UMUM (GL 3081)MINGGU KE-4

TIPOLOGI SISTEM AKUIFERTIPOLOGI SISTEM AKUIFER

Oleh:

Prof.Dr.Ir. Deny Juanda Puradimaja, DEAProf.Dr.Ir. Deny Juanda Puradimaja, DEA

Asisten:

Dr. D. Erwin Irawan

1Couse note for ITB student. Permission for other uses to Prof. Deny Juanda Puradimaja

D k i i AkifDeskripsi Akifer

Kelengkapan Gambar

P t (P b Akif )1. Peta (Penyebaran Akifer)

2. Gambar & Sketsa ‘Water Bodies’ (mataair, i k d i b h sumur, sungai, permukaan dan sungai bawah

tanah)

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D k i i AkifDeskripsi Akifer

1 Nama batuan pembentuk akifer1. Nama batuan pembentuk akifer2. Sifat properti akifer

(Warna, ukuran butir, bentuk tubuh akifer, porositas & b l )permeabilitas)

1. Geometri Akifer(Berlapis menerus lensa terpatahkan dll)(Berlapis menerus, lensa, terpatahkan, dll) Bagian atas akiferBagian dasar akifer, khususnya lapisan i b limpermeabelJenis sistem akifer (akifer bebas, tertekan, kombinasi)

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)Sistem input/output air (Recharge & Discharge) serta sifatnya (lokal atau regional)

PETA HIDROGEOLOGI INDONESIA SKALA 1 2 500 000INDONESIA SKALA 1 : 2.500.000

Couse note for ITB student. Permission for other uses to Prof. Deny Juanda Puradimaja

LEGENDA

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Jalur Gunung Api di Indonesia

 

North100

o105

o

110o

Jakarta KarahaTalagaBodasKarang

Pulasari Gede

North5o

J A W A

Iyang ArgapuraSurabaya

Yogyakarta TamboraIjen SaLamongan

Arjuno-Welirang

Kld

Lawu

Wilis

Ciremai

Talaga Bodas

Slamet

SundoroSumbing

Merbabu

Dieng

Merapi

Butak PetaranganKiaraberes

UngaranBandung

PulasariTangkuban Perahu

Patuha

Perbakti

SalakGede

Gagak

Galunggung

KwManuk

Guntur

Papandayan

Kamojang

WayangWindu

PatuhaPatuhaPatuha

0100200300

10o

YogyakartaBALI

LOMBOKSUMBAWA

TamboraRinjani

Agung

BaturIjen

Raung

Sa

Bromo

Semeru

KeludKw. ManukWayang Windu

S U M A T RA

PAPUA

KALIMANTAN SULAWESI

N

105o

110o100o

R AJAWA

105 110o100

6DEI-CP,2009

Gunung Ciremai (Google Earth, 2008)

U• Gunung api solitaire (3072

mapl) Umapl).• Terletak 20 km ke arah

selatan dari Cirebon • Observasi 140 mata air:

Jan 2006 – Dec 2007.

7

Peta topografi

Citra SRTMMetodologi: Diagram Alir Penelitian

Peta geologi

Peta hidrogeologiKlasifikasimata air

Analisis regional

Observasi mata air:Litologi & geometri

Sifat fisik air tanah:Q T TDS EC H

Analisis:1 Diagram Piper

Kendali geologiterhadapmata air

Asal mula mataair

Genesaair tanah

Q, T, TDS, EC, pH

Sifat kimia air tanah:Ca2+, Na+, Mg2+, K+, HCO3

-, Cl-, SO42-

1. Diagram Piper2. Korelasi3. Komponenutama4. Klaster5. Hidrograf

air

Delay time, sistem akuifer,Kawasani b h

Sistem input/Output air tanah

Data time series hidrograf: Q, TDS, EC

imbuhan

P i

Model hidrogeologipola aliran air

Penyaringandata

Model hidrogeologi &Pola perubahan sifatfisik dan kimia air tanah po a a a a

tanah

8

tanah

DEI-CP,2009

Preparasi DataContoh Analisis

ion utamaContohair tanah ion utama

di laboratorium

Konsentrasiion utama:Ca2+,Mg2+,Na+,K+,Cl-,SO4

2-,HCO3-

Konversimg/L -> meq/L=m ion/Ar * valensi

P i d t (I Ch B l )Penyaringan data (Ion Charge Balance)(Σ kation - Σ anion) / (Σ kation + Σ anion) x 100%

≤5% diterima ≥5% dikeluarkan

An korelasi An Statistik

9

An.korelasi An.StatistikMultivariabel

DEI-CP,2009

Kondisi Geologi Gunung Ciremai (Situmorang 1995)

U Breksipiroklastik

U

BT

piroklastik

Lava

T

Breksi lahar

SFm. Halang

Fm. Kaliwangu

10DEI-CP,2009

Penampang Geologi Gunung Ciremai (berdasarkan Situmorang 1995, digambar ulang oleh Irawan dkk., 2006)2006)

Morphology: Gradual slope with angle from 10 to 42Deposits: piroklastik fall at higher than 2500 masl, lava 500 -2500 masl dan volcanic breccias at 100 - 500 mdpl. The V l i d it t ti di t

oo Morphology: Sharp slope angle from 10 to 35. Occurrence of old crater rim.Deposits: mainly lava with pyroclastic fall l t th t

o

o

+ +

Piroklastik fall Piroklastik fallPyroclastic fall

Morphology: gradual slope with angle from 10-42o. Deposits: pyroclastic fall at higher than 2500 masl, lava at 500-2500 masl, and

l i b i 100 00 l Th

Morphology: sharp slope from 10 to 35o, occurrence of older crater rimDeposits: mainly lava with pyroclastic fall layers at the top

30o

42o

35o

Volcanic endapans sit on tertiary sediments layers at the top

+

++++

++++

?

Sequence of lava flow++

+

, ,volcanic breccias at 100-500 masl. The volcanic deposits sit on tertiary sediments.

layers at the top

Tertiary sedimentary

U S

10o

15o

10o+?

LaharSedimentaryrock

Lava flowLava flow

++

+ +

+

Lava flowLava flow

sedimentary

rock

Morphology: Gradual angle from 10 to 42with normal faultEndapans: pyroclastic fall at higher than 2000 masl, lava 1250 - 2000 masl dan pyroklastic flow at 500- 1250 masl. The Volcanic deposits sit on tertiary sediments

oo Morphology: Gradual angle from 10 to 42with normal faultDeposits: pyroclastic fall at higher than 2000mdpl, lava 1250 - 2000 mdpl dan piroklastik aliranat 750 - 1250 mdpl. The vulkanikendapans sit on tertiary sedimentary batuans

oo pyroclastic fall pyroclastic fall

Lava flow

++++++

+++++

?

Pyroclastic fallMorphology: gradual angle from 10 to 42o

Deposits: pyroclastic fall at higher than 2000 masl, lava at 1250-2000 masl and pyroclasticflow at 750-1250 masl. The volcanic deposits sit on tertiary sedimentary rocks.

Morphology: gradual slope 10-42o with normal faultDeposits: pyroclastic fall at higher than 2000 masl, lava at 1250-2000 masl, and pyroclastic flow at 500-1250 masl. The volcanic deposits sit on tertiary sediments.

Lava flow

35o

48o

33o

2o

10o

20o

Sequence of Lahar depositsPiroklastik flow

10o

Sequence of lahar depositsPyroclastic flow

11

2o

W EB T

DEI-CP,2009

Model Gunung Api Strato Fuego (Cas dan Wright, 1987)

olc

anic

or

e

cVo

co

Pro

xim

alvo

lcan

ocla

stic

faci

es

icM

edi

al

volc

anoc

last

ifa

cies

Dis

tal

volc

anoc

last

icfa

cie

s

ore

D v f

Off

sho

Model Fuego

G Ciremai

Lavas

Air fall deposits

Pyroclastic debris flow deposits

Fluvial channels

G. Ciremai

12

Hasil Observasi 140 Mata Air

)

16 mata air

si(m

apl)

52 mata air

Ele

vas mata air

72 t imata air

13PiroklastikLavaLahar

DEI-CP,2009

Contoh Skema Geometri Mata Air Depresi(Mata Air Cibulan 544 mapl)(Mata Air Cibulan, 544 mapl)

?

Tampak depan

Tampak samping

Lahar

Elevasi : 544 maplQ : 104 L/d

Air tanah

Q : 104 L/dTDS : 109 ppmEC : 218 μS/cmpH : 7,9T : 24,7 oC

14DEI-CP,2009

Contoh Geometri Mata Air Rekahan(Mata Air Bandorasa, 650 mapl)

1,8 m??

Tampak Tampak

5 m

Elevasi : 650 maplQ 33 7 L/d

Tampak depan

Tampak samping

Tanah pelapukan Q : 33,7 L/dTDS : 108 ppmEC : 216 μS/cmpH : 7T : 22,8 oC

Air tanah

Lahar

Tanah pelapukan

15DEI-CP,2009

Beberapa Contoh Foto Hasil ObservasiLapanganp g

Cigugur Citambak Palutungan Telaga Remis

Cikalamayan Citambak Cikole Cikabuyutan

Cijambu Cijambar Cileles Telaga Remis

16

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