``MERIT-Hydro`` Geospatial Dataset
==================================

In this file, the necessary technical details of the dataset is
explained.

Location of the ``MERIT-Hydro`` Dataset Files
---------------------------------------------

The ``MERIT-Hydro`` geospatial dataset files are located under the
following directory accessible from multiple clusters:

.. code:: console

   # DRAC Graham HPC location
   /project/rpp-kshook/CompHydCore/merit_hydro/raw_data # rpp-kshook allocation

   # UCalgary ARC HPC location
   /work/comphyd_lab/data/geospatial-data/MERIT-Hydro # comphyd_lab allocation

   # Perdue University HPC location
   /anvil/datasets/geospatial/MERIT_Hydro # Anvil community storage

And the structure of the files is as following:

.. code:: console

   /path/to/dataset/files/
   ├── elv
   │   ├── elv_n00e000.tar
   │   ├── elv_n00e030.tar
   │   ├── .
   │   ├── .
   │   ├── .
   │   └── elv_s60w180.tar
   .
   .
   .
   └── %var
       ├── %var_n00e000.tar
       ├── %var_n00e030.tar
       ├── .
       ├── .
       ├── .
       └── %var_s60w180.tar

In each ``.tar`` file, there are multiple GeoTIFF (``.tif``) files that
cover the extents indicated in the parent ``.tar`` file name. For
example, the ``elv_n00e000.tar`` contains the following files:

.. code:: console

   /path/to/elv_n00e000.tar/contents
   ├── n00e005_elv.tif
   ├── n00e010_elv.tif
   ├── n00e015_elv.tif
   ├── n00e020_elv.tif
   ├── n00e025_elv.tif
   ├── n05e000_elv.tif
   ├── n05e005_elv.tif
   ├── n05e010_elv.tif
   ├── n05e015_elv.tif
   ├── n05e020_elv.tif
   ├── n05e025_elv.tif
   ├── n10e000_elv.tif
   ├── n10e005_elv.tif
   ├── n10e010_elv.tif
   ├── n10e015_elv.tif
   ├── n10e020_elv.tif
   ├── n10e025_elv.tif
   ├── n15e000_elv.tif
   ├── n15e005_elv.tif
   ├── n15e010_elv.tif
   ├── n15e015_elv.tif
   ├── n15e020_elv.tif
   ├── n15e025_elv.tif
   ├── n20e000_elv.tif
   ├── n20e005_elv.tif
   ├── n20e010_elv.tif
   ├── n20e015_elv.tif
   ├── n20e020_elv.tif
   ├── n20e025_elv.tif
   ├── n25e000_elv.tif
   ├── n25e005_elv.tif
   ├── n25e010_elv.tif
   ├── n25e015_elv.tif
   ├── n25e020_elv.tif
   └── n25e025_elv.tif

Spatial and Temporal Extents
----------------------------

The spatial extent of this dataset covers longitudes from ``-180`` to
``+180`` degress and latitudes from ``-60`` to ``+90`` degress. This
dataset is static and does not vary with time.

Dataset Variables
-----------------

This dataset has 6 main variables that are described in the following
table:

+----+---------------------------+---------------------------+----------+
| #  | Variable Name (used in    | Description               | Comments |
|    | ``gistool``)              |                           |          |
+====+===========================+===========================+==========+
| 1  | ``dir``                   | Flow Direction Map        |          |
+----+---------------------------+---------------------------+----------+
| 2  | ``elv``                   | Adjusted Elevation        |          |
+----+---------------------------+---------------------------+----------+
| 3  | ``upa``                   | Upstream Drainage Area    |          |
+----+---------------------------+---------------------------+----------+
| 4  | ``upg``                   | Number of Upstream        |          |
|    |                           | Drainage Pixels           |          |
+----+---------------------------+---------------------------+----------+
| 5  | ``wth``                   | River Width               |          |
+----+---------------------------+---------------------------+----------+
| 6  | ``hnd``                   | Height Above Nearest      |          |
|    |                           | Drainage                  |          |
+----+---------------------------+---------------------------+----------+

A description of all the variables included in this dataset is explained
on the ``MERIT-Hydro``\ ’s
`website <http://hydro.iis.u-tokyo.ac.jp/~yamadai/MERIT_Hydro/>`__.