Remote sensing e-course

Geomorphology & Hydrology analysis

Fatwa Ramdani

Geoenvironment, Earth Science, Grad. School of Science

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.

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

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 ()

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.,%20Zhu%20Q.,%20Gold%20C.%20Digital%20terrain%20modeling..%20principles%20and%20methodology%20(CRC,%202005)(ISBN%200415324629)(324s)_CsCg_.pdf

Activities! • Import file using GRASS

• Explore basic statistics

• Displaying the data:

– Create shaded relief

– Blend two raster data

– Produce RGB of DEM

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

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)

Landform based on topographic

O.D.A. Prima et al. / Geomorphology 78 (2006) 373–386

Resource: http://www.sciencedirect.com/science/article/pii/S0169555X06000791 http://www.sciencedirect.com/science/article/pii/S0169555X09002189#

Methodology for geomorphologic mapping analysis

Resource: http://www.sciencedirect.com/science/article/pii/S0169555X09002189#

Streams profiles

Streams profiles

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.

Source: http://www.fgmorph.com/fg_4_8.php

Resources: http://www.uvm.edu/~pdodds/files/papers/others/1968/scheidegger1968b.pdf http://www.uvm.edu/~pdodds/files/papers/others/1968/scheidegger1968c.pdf

Addons installation

Result

Result

Result

Result

Stream order based on Horton

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

Thank you!

Questions?