images. The combination of systems (DIGITAL IMAGE
PROCESSING, multi-date and multi-scale data analysis)
increases information generation capability and thematic map
generation facility. These modern techniques have contributed
tremendously towards terrain analysis, understanding of site
conditions, spatial distribution of features, and resources.
Analysis of remotely sensed data using standard
interpretation techniques is particularly useful in channel
change detection, identifying palaeo-channels, regional
landform distribution, as well as detection of shallow buried
channels and buried valleys under special conditions using
thermal IR and radar imagery. In radar imagery over extremely
dry sands of desert areas of Sahara in northern Sudan, buried
valleys at 1.5 meters depth below surficial cover have been
detected (SIR-A data, 1981). Dynamical aspects of
geomorphology, landslides etc. can also be monitored. Digital
enhancement techniques are useful for improved interpretation
of terrain features. The development of landforms depends on
the climatic regime, the operative processes of denudation and
sedimentation during and after their formation as well as their
intensity in time and space, and the rocks and materials (their
composition, nature, and structure) acted upon. Man-made or
anthropogenic causes also affect landform development.
The identification of landforms and geomorpholoical
domain on remotely sensed data is based on area association
(arid, mountainous, glacial, coastal, flood plain, tropical etc.),
association of features, landform shape and size, drainage
patterns/ dissection, relief, tone, texture, land use/land cover,
erosion and other patterns etc. leading to "convergence of
evidence" upon logical inductive and deductive reasoning.
Analytical "Keys" can also be developed for an area of study
based on field criteria and a priori knowledge of typical forms
as seen on images.
Remote sensing provides a regional, synoptic view and permits
recognition of large structural patterns and landforms over
contiguous geomorphic domains. It enables the location and
delineation of extent of identified features observed over large
areas. The repetitive coverage of terrain in multispectral
mode provided by satellite mounted sensors enables
comparison of scenes of the same location in different periods/
seasons. This is extremely valuable for monitoring change, as
well as extracting more information about significant earth
features from scenes by viewing under seasonal conditions
(temporal and spectral resolutions).
2. REGIONAL GEOLOGY AND TECTONICS
2.1 Study area and its existing conditions
The present study area covering the Yangon and its surrounding
region falls in 96° and 96? 15'E and 16? 45'and 17? N as
referred as map index of UTM Sheet No. 1969-01. The central
part of the Yangon comprises Miocene consolidated sediments
overlain by the Quaternary sands, silts and clay. Win Naing
(1972) stated the uppermost part of the Mingalardon Ridge as
the Irrawaddy Formation of Pliocene age. But, thinly laminated,
weathered shale exposed in Shwegondaing area during
excavation for motor road extension works in 2003 and
completely weathered sandstone during excavation for the
foundation of the Yanshin Centre at the Shwegondaing Junction
reveal that the lithological character is resemble to that
Miocene sediments exposed in the Taikkyi Taungnio area (Tint
Lwin Swe, 2002). Kyaw Htun (1996) explained that Thadugan
sandstone and Besapat alternations in the Thadugan area were
belonged to the Upper Pegu Group of Miocene age; namely, the
Kyaukkok and Obogone formations. In addition, some rock
exposed in the left and right abutments of Inyar Lake and
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
geological drilled data for water well at the junction of the
Inyar and the Damazete roads (Tint Lwin Swe, 1998) show that
the lithological type is especially similar to that of the
Thadugan.
The Quaternary sediments widely distributed at the
outskirt of the Yangon, consisting of thick, high plastic, stiff
clay underlain by sand and silt. Win Naing (1972) classified
generally the Quaternary sediments into valley-filled deposit
and the alluvium. The valley-filled deposit includes the
Pleistocene older alluvium of a particular type of terrace
deposit (Leicester, 1959 and Kyaw Htun, 1996) of
unconsolidated gravels, sands and silts and the alluvial is
younger age clayey deposit. The pattern and distribution of rock
basement and soil deposit are depicted in Figure (1).
INDEX
| amin ]
Quateceaes
Ee Se rei
ilr Foster tes
Lesownidy Fen
S Mp amieta
ME
Qon
Bxsapet Altcrietions
He Vinee Peage
Cry
Macrae)
1 Miles
S THINGASGNUN v, et Ae d
== ce LC AREE 9
Figure 1. Soil and rock distribution of the Yangon area
(Win Naing, 1972)
Tectonically, the Yangon is situated in the southern
part of the Central Lowland, which is one of three major
tectonic provinces of Myanmar. The Taungnio Range of the
Gyophyu catchments area of Taikkyi District, north of Yangon,
through the Thanlyin Ridge, south of Yangon forming a series
of isolated hill is probably resulted from the progressive
deformation (Ramsay, 1967) of the Upper Miocene rocks as the
eastern continuation of the subduction or stretching and
compression along the southern part of the Central Basin and
regional uplifting of the Pegu Yoma.
2.2 Yangon river in and around soil investigations
The different varieties of the individual soil characteristics are
Meadow and Meadow Alluvial Soil, Gley and Gley swampy
soils, Swampy soils, Lateritic soils, Yellow brown forest soils,
Dune forest & Beach sand, Mangrove forest soils and Saline
swampy meadow gley soils. The meadow soils which occur
near the river plains with occasional tidal floods are non-
carbonate. They usually contain large amount of salts. Meadow
Inte
Alluvial
They ha
neutral s
nMeadox
Gleysol)
lands ar
texture ©
strong ac
Figure
coastal
insignif
erosion
along t
Ayeyar
affecte
Ayeyar
Motam
sea wat
23 T:
This ar
where
around
relative
high w
from b
Many
build 1
underl
areas,
destru
coastal
