Exercise 3 - The summer monsoon and its floods - Continued
Download the LANDSAT TM images of Bangladesh of 1989 and 2000. The two GeoTIFFs show a part of Bangladesh just North-West of the confluence of the Ganges and Bramhaputra rivers in November 1989 and 2000. The LANDSAT TM images have a ground resolution of 150 m/pixel. The image size is 1008 x 950 pixels.
How many kilometres do the images cover?
Download the images and save them in a folder called 'Bangladesh'.
Download the shape files and save them in your folder 'Bangladesh'.
The two classes 'city' and 'town' appear in Discrete values and symbols. Change the properties by clicking the symbol and change the class "city" to a 'square marker size 10' and the class 'town' to 'a circle marker size 8'. The class 'TRAFFIC_UTM' also consists of different types, 'main road', 'main railway' and 'railway'. Change the properties as described before and choose an 'orange solid line size 4' for main roads, a 'black solid line size 4' for main railways and a 'black dash line size 3' for railways.
Activate the second image GANGES2000_MIX_TS.TIF and deactivate the shape file WATERBODIES_UTM and the first image GANGES1989_MIX_TS.TIF. Compare both images while activating and deactivating the image GANGES1989_MIX_TS.TIF and answer the following questions:
How does the vegetation cover change?
Why does the vegetation cover change even though both images were taken in November? How do the courses of the rivers, especially the Ganges, change? What problems appear while mapping the river system, due to changes in the watercourse? Which cities and towns seem to be endangered by floods? Find out the names of the cities and towns by choosing Tools>Identify. Then click the icon MapTips and select 'ADMIN_NAME'. Mark the city or town with the pointer and read the name.
What other objects are endangered by floods? What does that mean for the people living in endangered zones?
Last update: 18 April 2013
|