BEBERAPAPENGERTIAN DASAR

I. Geomorphology is the study of landforms

(Lobeck, 1939)

II. Geomorphology is the science of landforms

(Thornbury, 1954)

III. Geomorphology is the study which describes landforms and the process which their

formation, and investigates the interrelationship, of these forms and

process and their special arragement

(Van Zuidam, et. al., 1979)

FfPMdt

:::::

Landform (bentuklahan)Fungsi dariProsesMaterialPerubahan menurut waktu

IV. Geomorphology

• Studi mengenai bentuk bumi (Derbyshire, 1979, p. 15)

• Studi tentang bentuk lahan (landform)

Lingkup studi• Derbyshire, 1979, p. 17

F = f(P,M) dt

Derbyshire membedakan 4 level dari studi geomorfologi

Level 1 : study of elements of the equation(studi tentang bentuklahan, proses, dan material, masing-masing secara terpisah)

Level 2 : Balancing the equationMencari hubungan timbal balik antara bentuklahan, proses, dan material pada suatu daerah tertentu pada saat tertentu pula

Level 3 : Differenciating the equationTermasuk dalam hal ini pengujian cara-cara mengetahui hubungan timbal balik antara ketiga elemen tersebut dan variasinya menurut waktu

Level 4 : Applying the equationPenggunaan manfaat dari ketiga level tsb di atas untuk maksud pengelolaaan lingkungan

V. Geomorphology is the study of landforms, and in particular of their nature, origin, processes of development, and material composition. (Cooke, et. al., 1974)

VI. Geomorphology Dalam lingkup studi geomorofologi tercakup:

• Bentuk lahan (landform)• Proses-proses geomorfologi• Genesis (asal-usul/perkembangan jangka panjang)

(Verstappen, 1977, p. 2)

VII. Geomorphologyis the scientific study of landscapes and the processes that shape them. The science of geomorphology has two major goals.

1. One is to organize and systematize the description of landscapes by intellectually acceptable schemes of classification.

2. The other is to recognize in landscapes evidence for changes in the processes that are shaping them and have shaped them (Arthur Bloom)

http://www.uwm.edu/Course/416-403/geomorph_rs_apps.htm

Karmono Mangunsukardjo (1986) menjabarkan 4 aspek geomorfologi :

1. Studi mengenai bentuklahan, atau disebut dengan morfologi, mempelajari relief secara umum yang meliputi aspek :

a). MorfologiYakni aspek-aspek yang bersifat pemerian suatu daerah, antara lain teras sugai, beting pantai, kipas aluvial dan plato

b). MorfometriYakni aspek-aspek kuantitatif dari suatu daerah seperti kemiringan lereng, bentuk lereng, ketinggian, beda tinggi, kekerasan medan, bentuk lembah, tingkat pengikisan dan pola aliran

2. Studi mengenai proses geomorfologi,Yakni proses yang mengakibatkan perubahan bentuklahan dalam waktu pendek serta proses terjadinya bentuklahan yang mencakup morfogenesa, dengan aspek-aspek :

a). Morfo-struktur pasifmeliputi litologi (tipe dan struktur batuan) yang berhubungan dengan pelapukan

b). Morfo-struktur aktifberupa tenaga endogen

c). Morfo-dinamikberupa tenaga eksogen yang berhungan dengan tenaga angin, air, es, gerak masa batuan dan volkanisme

3. Studi geomorfologi yang menekankan pada evolusi pertumbuhanbentuklahan atau morfo-kronologi, menentukan dan memerikanbentuklahan dan proses yang mempengaruhinya dari segi umur relatifdan umur mutlak

4. Geomorfologi yang mempelajari hubungannya dengan lingkungan, studi ini mempelajari hubungan antara bentuklahan dengan unsur-unsur bentangalam seperti batuan, struktur geologi, tanah, air, vegetasi dan penggunaan lahan

Geomorphology should not be viewed as a product of lithosphere processes but as part of an integrated earth-surface system of interacting "sphere": lithosphere, hydorsphere, atmosphere, and biosphere. Geomorphology is an environmental science as much as it is a geologic science.

Landform (bentuklahan)Bentukan alam di permukaan bumi yang terjadi karena proses pembentukan tertentu

dan melalui serangkaian evolusi tertentu pula.

atau

Bagian dari permukaan bumi yang mempunyai bentuk khas sebagai akibat pengaruh

dari proses, struktur geologi, dan batuan selama periode waktu tertentu. Oleh karena

itu bentuklahan ditentukan oleh faktor-faktor topografi, struktur geologi, batuan, dan

proses eksogen.

atau

merupakan bentangan permukaan lahan yang mempunyai relief khas karena

pengaruh kuat dari struktur kulit bumi dan akbibat dari proses alam yang bekerja

pada batuan di dalam ruang dan waktu tertentu. Masing-masing bentuklahan

dicirikan oleh adanya perbedaan dalam hal struktur dan proses geomorfologi,

relief/topografi dan material penyusun/litologi (Strahler, 1983 dan Whiton, 1984).

Misal :

Teras sungai : proses sedimentasi oleh aktivitas sungai dan berkembang

sampai terbentuknya (evolusi)

Landscape (bentanglahan)Panorama atas suatu hamparan daratan yang terdiri dari berbagai keadaan alam baik alami maupun buatan manusia (artifisial).

TopografiMenyatakan ketinggian tempat di permukaan bumi dengan ukuran satuan ketinggian tertentu

TerrainMerupakan istilah yang diperuntukkan guna menyatakan keadaan medan suatu wilayah di permukaan bumi, baik keadaan reliefnya, vegetasi/penggunaan lahan, adanya sungai-sungai, rawa-rawa, sifat-sifat umum batuan dan lahan, dll. Istilah ini digunakan terutama untuk keperluan militer (PD I, II)

The collection, analysis, evaluation, and interpretation of geographicinformation on the natural and manmade features of the terrain, combinedwith other relevant factors, to predict the effect of the terrain on militaryoperations. Military Dictionary (DOD, NATO)

Digital Geomorphometry based on the use of DEMs is nowadays covered by the concept of terrain analysis (Wilson dan Gallant, 2000)

Digital Terrain Analysis The use of remote sensing satellite data for mapping various aspects of terrain, such as land cover, landuse, and soils. Software may then be utilized to derive terrain parameters, such as aspect, catchmentarea, and wetness index, which are then used to describe the morphology of the landscape and theinfluence of topography on environmental processes.

C:/Sleman/3_D/mobil_3D.sxd

© 2007 Intermap Technologies, Inc. All rights reserved.

Imagery

Digital

Terrain Data

(DEM)

3D

Digital Model

D:/Military/

Morphometric parameters • elevation change gradients (slope)

• orientation gradients (aspect, steepest downhill slope, viewshed)

• curvature gradients (horizontal or tangent curvature)

• vertical or profile curvature (mean curvature

• combined gradients (tangential curvature).

3D AnalystC:/Sleman/3_D/srtm_slm_box

Generic landforms– Stream channel (Valley bottom) - Locations of water accumulation and transition; high number of upstream elements and

concave shapes.

– Ridge (Peak) - Locations of water run-off; lowest upstream contributing area and convex shapes.

– Slope - Sloping part with generally higher shape complexity.

– Plain (Terrace) - Flat areas of low relief and low shape complexity.

– Pit - Conical concave landform.

D:/military/tinkrsb_ras

Topographic attributes: elevation (meters), slope (degree) aspect (degree), planform

curvature, topographic wetness and stream power

Topographic wetness and stream power indices were used to quantify flow

intensity and accumulation potential. Topographic wetness (also known as Compound

Topographic Index [CTI] or topographic moisture index) at a particular point on the

landscape is the ratio between the catchment area contributing to that point and the slope

at that point (Wilson and Gallant, 2000). Higher positive values are wetter and lower

negative values are drier and values are calculated as:

The Stream Power Index (SPI) is closely related to the topographic wetness index and is

used to estimate the erosive power of the terrain. Areas with large stream power

indices have a great potential for erosion. If total stream power is greater than that

required to transport the sediment available (supply limited), then there will be a net loss

in sediment and the stream will erode. If stream power is less (transport limited) than that

required, then there will be a net gain in sediment and the stream will aggrade. Values are

calculated as:

Stream power index = Catchment areaxtan β (Moore et al., 1993)

where β = Slope in degrees

GIS-Based Automated Landform Classification and Topographic, Landcover and Geologic Attributes of Landforms Around the Yazoren Polje, Turkey

Perencanaan dan Operasi Militer

Pemahaman karakteristik medan menentukan akses yang efektif

Drop Zone 1

Drop Zone 2

Target Objective

RELIEF

a. ReliefBentuk wilayah : keadaan tinggi rendah suatu wilayah di permukaan bumi ditinjau dari segi perbedaan tinggi dan kemiringannya (lereng)

atau Bentuk ketidakteraturan secara vertikal, baik dalam ukuran besar maupun kecil dari permukaan litosfer.

Misal :datar, landai , berombak, bergelombang, berbukit kubah(humocky), berbukit, bergunung.

HUBUNGAN RELIEF LERENG DAN BEDA TINGGI (US Soil Survey)

Relief Lereng (%) Beda tinggi (m)

Datar/hampir datar 0-2 <5

Berombak/Topografi landai 3-7 5-50

Berombak-bergelombang, topografi

miring

8-13 25-75

Bergelombang-berbukit, topografi

dengan lereng sedang

14-20 50-200

Perbukitan/topografi terjal 21-55 200-500

Pegunungan/topografi sangat terjal 56-140 500-1000

Pegunungan sangat curam >140 >1000

RELIEF :1. datar (D) 2. landai (L) 3. berombak (B) 4. bergelombang (Gb) 5. berbukit kubah (humocky)/Bk 6. berbukit (Bt) 7. bergunung (Gn)

HUBUNGAN RELIEF LERENG DAN BEDA TINGGI (Sunardi J., 1985)

Relief Lereng (%) Beda tinggi (m)

Datar 0-3 <5

Landai/berombak 5-8 5-10

Landai/Miring 8-15 10-25

Miring/berbukit 15-25 25-100

Miring terjal/ berbukit terjal 25-45 100-200

Terjal (berbukit terjal) 45-100 200-500

Sangat terjal (bergunung) >100 >500

Panjang LERENG (US Soil Survey)

Panjang Lereng (m) Keterangan

0 - 15 Sangat pendek

25 - 50 Pendek

50 - 250 Panjang menengah

250 - 500 Panjang

> 500 Sangat Panjang

Landforms evolve through the slow erosional removal of weaker rock, leaving the more resistant rock standing as ridges or mountains. (Drawn by A. N. Strahler.)

Komponen dari relief yaitu :a. amplitude (beda tingggi antara lembah dan puncak)b. bentuk punggungc. bentuk lerengd. bentuk lembah

Aspek relief yang lain :1. hubungan antara unit reliief kemiringan lereng dan

perbedaan tinggi relief2. kepadatan aliran3. pola aliran sungai

The concept of slope gradient. (a) How slope is measured on the landscape and the two ways in which it can be expressed (degrees and percent). (b) Limits and definitions of slope classes used by the Natural Resources Conservation Service. Map units with complex slopes require the use of more than one term, e.g., “steep and moderately steep.” The overlap of ranges allows them to be specifically set for each survey area. After the Soil Survey Division Staff (1993).

Geomorphic components of slopes in a landscape with an open drainage system. After Ruhe (1975b).(b) Two-dimensional components, i.e., the five elements of “fully developed” slopes.

Examples ofSimple (S), Compound (C), Complex (Cx) hillslope profiles, slope breaks (Br), as viewed in cross-section. After Ahnert (1970).

The nine basic geometric forms of hillslopes, with flowlines illustrating

how water and debris (theoretically) moves on them. After Ruhe (1975b) and Huggett (1975).

Pediment adalah lapisan tanah dasar / batuan dasar yang sangat landai (kemiringan sekitar 5°).

Tallus adalah fragmen batuan yang terakumulasi sebagai tumpukan didasar bukit atau tebing.

• Morfologi Positif:– Gunung (Mountain)

– Bukit (Hill)

– Kubah (Dome)

– Punggungan (Ridge)

• Morfologi Negatif– Lembah (Valley)

– Cekungan (Basin)

Komponen dari relief yaitu :a. amplitude (beda tingggi antara lembah dan puncak)b. bentuk punggungc. bentuk lerengd. bentuk lembah

Aspek relief yang lain :1. hubungan antara unit reliief kemiringan lereng dan

perbedaan tinggi relief2. kepadatan aliran3. pola aliran sungai

http://www.sciencedirect.com/science/article/pii/S0016706110003976

: Mountains

: Alluvial fans

: Valleys

: Wash drainage areas

(Reprinted with permission, Leighty (2004)

Pola aliran merupakan cerminan dari struktur dan tipe/ komposisi

batuan. Sedangkan kerapatan aliran mencerminkan resistensi dan

kekedapan batuan.

Studi tentang drainase pada foto udara atau data PJ meliputi 3

aspek :

1. tekstur drainase (drainage texture) atau kerapatan aliran

2. bentuk lembah (valley shape)

3. pola drainase (drainage pattern)

tekstur drainase merupakan kerapatan drainase (rasio

total panjang sungai dalam sebuah DAS) dan frekuensi

drainase (jumlah aliran sungai dalam DAS dibagi

dengan luas DAS).

1. Tekstur Drainase (drainage texture) atau Kerapatan Aliran

Tekstur drainase atau Kerapatan Aliran terutama dipengaruhi oleh tiga

faktor :

a) Iklim,

b) Relief

c) Karakter dari batuan dasar atau tanah (yaitu porositas dan

permeabilitas).

Kerapatan aliran dapat dideskripsikan sebagai:

• sangat halus (ultra fine),

• halus (fine),

• sedang (medium),

• kasar (coarse)

Kerapatan aliran mencerminkan resistensi dan kekedapan batuan.

Ex : Batuan beku/volkanik: gabro. granite

Batuan kompak dan permeabel

Batuan lunak dan impermeabel

Kerapatan aliran jarang

Kerapatan aliran rapat

Kerapatan aliran

Drainage textures: (i) Coarse and (ii) fine

Drainage density

Texture DD (km/km sq.) Conditions

Coarse (low) <8• Permeable or resistant

• Humid and well vegetated

Medium 8-20

• Permeable rksh.

• Rainfall

• well vegetated

Fine (high) 20-200

• Impermeable surface

• Low rainfall

• Little vegetation

Ultra fine >200

• Impermeable surface

• Low rainfall

• easily erodible rocks

• little vegetation

The interpretation of DD varies with map scale. Typically its measured on a scale of

1:24,000.

http://w3.salemstate.edu/~lhanson/gls210/gls210_streams3.htm

C = clayshale

SC = sandy or silty clay

Ss = sand or sandstone

Texture Common

Coarse gravel(ly)

Medium sand(y)

Fine clay(ey)

Drainase dikatakan internal ketika beberapa garis drainase terlihat di

permukaan dan sebagian besar di bawah permukaan (sub-surface),

misalnya batugamping (limestone) dan kerikil (gravel).

Drainase eksternal di mana jaringan drainase terlihat baik di permukaan.

Kerapatan drainase rendah pada batuan permeabel, seperti: tanah liat

(clays), serpih (shales).

argillaceous = “berlempung”

untuk menentukan batu di mana mineral lempung merupakan komponen

sekunder tapi signifikan. Misalnya, batugamping berlempung (argillaceous

limestones ) adalah batugamping yang terdiri sebagian besar dari kalsium

karbonat, tetapi termasuk 10-40% dari mineral lempung: batugamping tersebut, ketika lembut, sering disebut napal. Demikian pula, argillaceous sandstones (batupasir berlempung) adalah batupasir yang terutama terdiri

dari biji-bijian kuarsa, dengan ruang interstitial penuh dengan mineral

lempung.

Calcareous = “berkapur”

Berkapur adalah kata sifat yang berarti sebagian besar atau sebagian

terdiri dari kalsium karbonat, dengan kata lain, mengandung kapur atau

menjadi kapur.

Arenaceous = “berpasir”

batuan klastik sedimen dengan ukuran butir pasir antara 0,0625 mm

(0,00246 in) dan 2 mm (0,08 in) dan mengandung kurang dari 15% matriks.

Bentuk lembah dapat bervariasi terkait dengan batuan dasar atau tanah.

• Bentuk V sering berkembang di pasir (sands) dan kerikil (gravels),

• Bentuk U berkembang di tanah lanau (silty soils).

• Bentuk lembah yang panjang dengan penampang membulat

menunjukkan tanah lempung (clayey soils) .

2. Bentuk lembah (valley shape)

Typical valley cross-sections : (i) V-shaped, (ii) U-shaped and (iii) gently rounded

3. Pola drainase (Drainage pattern)

adalah “spatial arrangement” dari sungai (streams).

Batuan miring

Batuan yang landai dan homogen

Batuan dengan struktur kekar dan sesar intensif

Struktur lipatan

pola aliran pararel

pola aliran dendritik

pola aliran rektanguler

pola aliran trellis

Pola aliran merupakan cerminan dari struktur dan tipe/ komposisi batuan.

DENDRITIC

• Tree

• Uniform Rock

TRELLIS

• Alternating

layers of hard

and soft rock

• Parallel

streams

RADIAL

• From highest central

point (butte/conical hill)

RECTANGULER

• Bends 90o

• Tributaries 90o

• Joint and faults

Dendritic drainage pattern.- Also called trees like or arborescent. Most common

basic pattern. F is fine texture; C is coarse texture. No structural control. Occurs

on fine textured impervious material.

Von Bandat, “Aerogeology”

Modification- of dendritic pattern. Tributaries of fourth and third order show Pincer-like

curved forms. Occurs on igneos intrusions.

Anak sungai acara urutan keempat dan ketiga bentuk melengkung

Subparallel-dendritic pattern. Coastal plain type. Flat bottomed broad short channels of limited

extent. Elongated tributaries at the right developed due to tilt of the surface (arrow). Broad channels

develop in fine sandy material.Von Bandat, “Aerogeology”

Von Bandat, “Aerogeology”

Dendritic-pinnate pattern.

There is no structural control. P is a plain surface: The material is sandy and clayey silt.

(Ripley Cy., Indiana, U. S. Dept. of Agriculture)

Von Bandat, “Aerogeology”

Dendritic-pectinate pattern. Featherlike design typical with loess. Parallel gullies with

pearshaped headwater basins. Main stream in flat bottomed valley. P is a loss surface

(After Belcher).

Von Bandat, “Aerogeology”

Modifications of dendritic pattern. Different designs develop in clayshale (C), sandy or silty clay

(SC), and sand or sandstone (Ss). The different is in shape, ramification, type, texture and length

of gullies. C is most ramified, tree-like, fine textured. S is more wide spaced, less ramified with

short straight gullies. SC is finer textured with longer ramified gullies; a type between C and S

(Sweetwater Cy., Wyoming, USGS)

Von Bandat, “Aerogeology”

Angular drainage pattern. This basic type is also called a trellis pattern. A and B.

are two tilted sandstone blocks. The pattern is fault controlled. It is found on fractured

granular deposits or intrusives.

http://www.asu.edu/courses/gph111/Hydrology/Trellis.jpg

Von Bandat, “Aerogeology”

Angulate pattern, a modification of the angular pattern. The minor tributaries are parallel,

joining the main tributaries at obtuse angles. The pattern is fracture controlled and is found

mostly in granular sediments, like sandstones in near horizontal attitudes.

Von Bandat, “Aerogeology”

Contorted drainage pattern. The streams show reversed flow (arrows). The material is

sandstone. The control is structural.

Von Bandat, “Aerogeology”

Parallel patterns. This basic pattern develops on fine textured material with steep slopes.

Also along laminated formations of diffrent resistance, e.g., sand stone-shale belts, or on

tilted valley fills. It is most common along steep clay scarps with obsequents streams.

Von Bandat, “Aerogeology”

Subparallel pattern. The parallel tributaries join the main stream at an angle. This type is

common coastal plains in fine material, or on lava streams.

Von Bandat, “Aerogeology”

Radial drainage Pattern. The consequent streams flow from a central area in a radial design. The

design is from an Indonesian volcano. The material is fine textured tuff and granular tuff at G. This

basic pattern can be centrifugal (positive) on domes or uplifts and centripetal (negative) in basins.

Von Bandat, “Aerogeology”

Annular drainage pattern. The rather rare design occurs on domes with concentric hard and

soft upturned beds, or basins of similar composition.

Von Bandat, “Aerogeology”

Radial, pincerlike-dendritic and annular drainage pattern on a small granite dome.

Dashed lines with arrow are hard upturned bedded sediment, ridges. The central

granite ridge with apex is at G. (Meade Cy., South Dakota)

Von Bandat, “Aerogeology”

Sinkhole pattern develops on soluble rocks like limestone, gypsum, dolomite. Sink are usually

roundish or oval shaped. Only short rudimentary surface channels develop. The shallow

basins are filled with residual clay.

Von Bandat, “Aerogeology”

Drainage pattern in tropical Karst. Three different types of limestones (A, B, C) show three types of

sinkholes and dissolved fractures. The dry surface channel is fracture controlled. The angular

boundary between the limestone types suggests fault contacts. ( After a Bataafsche Petroleum

Maatschappij photograph)

Von Bandat, “Aerogeology”

Dichotomic pattern. The streams radiating from a common point in a fan shaped manner depositing granular material by branching and multiple bifurcation (dichotomy). This design is found on alluvial fans and deltas.

Von Bandat, “Aerogeology”

Anastomotic drainage pattern with meandering stream. Oxbow lakes (O) and meander scars ( M) are on abandoned channels. Because of the collateralcommuting food channels, the pattern is called anastomotic. This depository pattern in common on floodplains may be, in part, structure controlled.

This photograph shows a __________ stream channel

a. meandering

b. undercut

c. gradient

d. straight

e. braided

This image shows an area in the Appalachian Mountains in Pennsylvania. The type of drainage pattern that generally characterizes this region is __________

a. annular

b. Trellis

c. rectangular

d. dendritic

e. deranged

This photograph shows part of the Kalahari Desert [Africa]. The drainage pattern is evident as a series of dark and light stripes that follow patterns of fossil sand dunes from an ancient desert. Parallel channels intersect a larger stream following a fault on the left side of the image. Together, these geologic controls create a __________ drainage pattern.

a. trellis

b. rectangular

c. annular

d. radial

e. dendritic

This karst region in Slovenia represents which type of drainage pattern?

a. rectangular

b. radial

c. deranged

d. annular

e. dendritic

f. trellis