==================
Flooding the  Alps
==================

:Author: D.Thaler
:Created: Nov 2012
:Last changed: 2019-06-27

With the help of digital elevation model data one can see what happens
if the sea level rises in the area of the European Alps. The goal is
not to satisfy apocalyptic fantasies but to illustrate the diminishing
blocking effect for vertically extended outbreaks of cold air.

.. image:: ../pics/alpflood/eastalps1200.jpg
   :width: 600

With increasing height the gaps in the mountain barrier become more
and more frequent. Lee effects can better be estimated with that
special picture in mind. Weather forecasters should be aware of that.

Download videos
---------------

All videos can be watched e.g. with a recent version of the open
source `VLC Media Player <https://www.videolan.org>`_.  

+---------------------+-----------------+-----------------------------------------------------+
| Area                | Data source     | Download                                            |
+=====================+=================+=====================================================+
| Alps                | GTOPO30         | :download:`alps_hd_10fps10m.avi                     |
|                     |                 | <../videos/alp_flood/alps_hd_10fps10m.avi>`         | 
+---------------------+-----------------+-----------------------------------------------------+
| Austria             | GTOPO30         | :download:`austria_hd_15fps05m.avi                  |
|                     |                 | <../videos/alp_flood/austria_hd_15fps05m.avi>`      |
+---------------------+-----------------+-----------------------------------------------------+
| Eastern Alps        | GTOPO30         | :download:`topo_eastalps_hd_slow.avi                |
|                     |                 | <../videos/alp_flood/topo_eastalps_hd_slow.avi>`    |
+---------------------+-----------------+-----------------------------------------------------+
| Austrian            | SRTM            | :download:`topo_centralalps_hd_slow.avi             |
| Central Alps        |                 | <../videos/alp_flood/topo_centralalps_hd_slow.avi>` |
+---------------------+-----------------+-----------------------------------------------------+
| Austria -           | SRTM            | :download:`ennstal_hd_15fps05m.avi                  |
| Area Ennstal        |                 | <../videos/alp_flood/ennstal_hd_15fps05m.avi>`      |
+---------------------+-----------------+-----------------------------------------------------+

*The average size of the video files is about 20 to 40 Mbyte.*

How was it done?
----------------





Following DEM-Data has been used:

* 30 arc seconds (~ 1km) DEM **GTOPO30** `earthexplorer.usgs.gov <https://earthexplorer.usgs.gov>`_

* 90m-DEM **SRTM DATA** VERSION 4.1 `srtm.csi.cgiar.org <http://srtm.csi.cgiar.org>`_

The core work was done with *Python 2.7* with the help of the python modules:

* **numpy** (calculations)

* **matplotlib** (plotting)

* matplotlib tool-kit **basemap** (plotting maps)

* **gdal/osgeo** (doing GIS-work)

* After having produced quite a lot of Jpg-images *AVI-movies* were
  produced with the help of **mencoder**.

All libraries were used in the versions delivered with *Ubuntu Linux
12.04 and 14.04*. In most other Linux distributions all necessary programs
should be available by their standard repositories.

Program sources
---------------

:download:`topoflooding.zip <../downloads/topoflooding-0.2.0.zip>`
contains the the main python program **topoflooding.py** and the
config file template **configfile_template.py**.
	  

**Usage**:

* Make sure you have installed

  - *python 2.7* (should also work with python 3.x)

  - *matplotlib 1.1.1* or higher

  - *basemap 1.02* or higher

  - *python-gdal 1.7.3* or higher

  - *mencoder* or another movie-maker program

  and all their dependencies.
  
* Download *topoflooding* and *configfile_template.py* in a separate
  directory

* Make sure you have a DEM-file in a format supported by gdal (compare
  supported formats in `gdal documentation
  <http://www.gdal.org/formats_list.html>`_)

* edit *configfile_template.py* concerning to your needs to
  *yourconfigfile.py*
  
* Call ``python2 topoflooding.py yourconfigfile.py``

* call *mencoder* or any other movie-maker tool to make a movie of the
  image files

----------------------------------------------------

Any comments to **info at foehnwall dot at**