Accuracy levels and resolution for Flood plain mapping. I am working on Pune District. The objective is that I generate Flood maps for different recurrence intervals, using HECRAS and GIS.
Please suggest some critical comments on this .
Pawar A D
dear Amol ji you can freely download SRTM at 90m and ASTER at 30m resolution data from following link
http://glcf.umd.edu/data/
http://gdem.ersdac.jspacesystems.or.jp/login.jsp
if you have any difficulty in further data processing in software .. you can share your question with me.......
Hi Amol.
With regard to the SRTM and ASTER DEMs, proposed by Kuldeep in the previous message, while they are very good resources in general, in my honest opinión such DEMs are not suitable to perform flood mapping, by far they don't meet the mínimum accuracy requirements.
Nevertheless, it depends on the accuracy required, the mapping scale and the topographical characteristics of the site (i.e., steepness). The flatter the flood plain, the bigger the accuracy required.
Regards.
The best would be of course a Digital Surface Model (DSM) based on LiDAR. For flood modeling a DEM must contain all the relevant surface features that direct the flow of water. I'm not aware of any LiDAR data freely available for MH.
If you do not have access to LiDAR, try with the DEM based on Cartosat (2.5 m) Stereo Images. Attached link provides how to access & generate a DEM from Cartosat Stereo Images.
I agree that the conventional Global DEM Data like the GTOPO, SRTM, ASTER may not be appropriate for detailed, site specfic, large scale flood modeling studies because of resolution and data gaps. Unless, you want to do a general small scale flood modeling for a whole region like that of the entire Pune city, you can try them out anyway. The German TerraSAR-X & TanDEM-X WorldDEM with a vertical accuracy of 2m (relative) and 10m (absolute), with 12x12 sq. m. resolution is promising. Therefore check them out too for your research.
Alternatively, there are a whole bunch of commerical satellites operational with Stereo capabilities like the IKONOS, QuickBird, Pleiades-1A, SPOT, ALOS etc. which you can obtain. Obviously, you need to have a good supply of cash to order them!
In general, I think it would be appropriate to first look at the scale of your study area, the level of details you want to model and to then choose a specific elevation model which fits your research objectives rather than looking at which DEMs are available and then trying to fit one to your area of interest.
You can also follow the interesting discussion link on 'which DEM is best'.
There have been some studies based on HECRAS and GIS in the US, India and elsewhere. Follow the link for articles
Good Luck Mr. PAwar!
https://www.researchgate.net/post/How_do_you_generate_DEM_from_Cartosat-1_STEREO_data
https://www.researchgate.net/post/Among_DEM_techniques_which_one_is_most_accurate
https://www.researchgate.net/search.Search.html?type=publication&query=hecras
http://bhuvan.nrsc.gov.in/data/download/index.php
- Badges
- Science topic
- Similar topics
- Geoscience
- Asia
- India