2. Outline
• This course will focus in geomorphology and hydrology analysis
based on remotely-sensed data, SRTM. The methods how to
analyze and exploit the SRTM information for geo-hydrology
mapping will be illustrated in open source software.
• In every section will be follow with the exercise and questions to
allow student expand their understanding.
3. Course Goal and Objectives
• Understand the concept of DEM, DTM, DSM
• Understand formula module function in open source software
• Understand the benefit of drainage pattern to identify
physical environment
• Understand the stream order
• Understand basic cartography design
4. Intended Audience
• University student with basic level of
knowledge in Remote Sensing studies
• Course Requirements:
–
–
–
–
Internet access
GRASS software (http://grass.osgeo.org/grass64/binary/mswindows/native/)
QuantumGIS software (http://www.qgis.org/en/site/forusers/download.html)
Download data here ()
5. 1. Using DEM image for landscape
analysis
• This lesson will focus in DEM analysis based on remotely-sensed data,
SRTM. The methods how to analyze and exploit the DEM information for
geo-hydrology mapping will be illustrated.
Resources:
•
•
http://www.cgiar-csi.org/data/srtm-90m-digital-elevation-database-v4-1
http://f3.tiera.ru/2/Cs_Computer%20science/CsCg_Computational%20geometry/Li%20Z.,%2
0Zhu%20Q.,%20Gold%20C.%20Digital%20terrain%20modeling..%20principles%20and%20me
thodology%20(CRC,%202005)(ISBN%200415324629)(324s)_CsCg_.pdf
6. Activities!
• Import file using GRASS
• Explore basic statistics
• Displaying the data:
– Create shaded relief
– Blend two raster data
– Produce RGB of DEM
7. 2. Generating watershed and streams
(hydrologic analysis)
•
This lecture will introduce the student to and will be follow with the exercise and
questions to allow student expand their understanding.
ACTIVITIES
• Filling the data
• Generating slope, aspect and drainage network
• Thinning the data, create contour, and convert to vector
• Working with low-pass and high-pass filter
• Analyzing the result associated with the physical environment
Resource
8. Drainage pattern associated with physical
environment (landscape & geology)
A dendritic drainage pattern is the most common form and
looks like the branching pattern of tree roots. It develops
in regions underlain by homogeneous material. That is, the
subsurface geology has a similar resistance to weathering
so there is no apparent control over the direction the
tributaries take. Tributaries joining larger streams at acute
angle (less than 90 degrees)
13. Streams Order
Stream order is a method for classifying the relative location of a Reach within the
larger river system.
This system shown here is the Strahler (1957) modified Horton (1945) method for
Stream order, which assigns each headwater perennial Stream an order of 1, and then
at the confluence of two 1st-order Streams assigns the downstream Reach an order of
2. In this method, the confluence of two 2nd-order Streams results in a downstream
Reach of order 3, and so on, as illustrated by this picture.
Resources:
http://www.uvm.edu/~pdodds/files/papers/others/1968/scheidegger
1968b.pdf
http://www.uvm.edu/~pdodds/files/papers/others/1968/scheidegger
1968c.pdf
Source: http://www.fgmorph.com/fg_4_8.php
20. Quiz?
• Describe the DEM you use in this study. Write a well
structured paragraph or two on raster filtering to answer
the following:
– What is the difference between a low pass and a high pass
filter?
– Why would you want to run a low pass / high pass filter on a
DEM?
– Is slope a high pass or a low pass filter operation?
– Which basin or sub-basin are have different geomorphological
structure? Shows in map!
– Whay stream order is important?
• HOMEWORK!
– Do the same procedure to produce basins map, streams, etc
using ASTER GDEM data and compare the result