| In order to use the Google Earth interface, you will first need to download and install
Google Earth. You can, however, access the tabular data without Google Earth.
|
| On the main water resource explorer page, choose whether you wish to browse
by primary drainage region, water management area, hydrological sites on rivers or hydrological sites on dams.
Primary drainage regions are the broad hydrological catchment areas in South Africa,
while water management areas are the water administrative regions. The hydrological sites are the approximately 3000
gauging stations on rivers and dams (lakes): these are the links of interest
to hydrologists. |
| Clicking on the primary drainage region link takes you to a table of drainage regions.
If you are unfamiliar with this classification system, choose Select sites from map.
Otherwise, choose your drainage region of interest from one of the columns. The first four
columns assume that you have Google Earth installed while the last two take you to simple but rather
large tables of sites. |
| The data set includes thousands of boreholes (wells) with only one or two results each,
hence the grouping of sites into no boreholes and with boreholes. Within a group, choose to
show either simple icons at each site, or the more complex Maucha diagrams (useful if you are interested in
the ionic composition of the water). |
| If you are just trying out the system, choose Google Earth, no boreholes - Icon markers -- K: Kromme et al. |
| Depending on your browser configuration, Google Earth may open the file automatically,
but sometimes you need to save the K_reg_WMS_nobor.kmz file and open it manually. You can look for
possibe solutions to problems of this kind at
Google Earth Hacks Forums.
|
| When all the above steps have worked correctly, you will see a piece of the South African
coastline (the Garden Route). The Places panel on the left will contain a new hierarchy
labelled K surface with icons labelled Canal, Rivers, etc. |
If no monitoring sites are visible on the 3D-viewer, you need to expand the time slider at the
top right of the viewer: select the right-hand edge of the sliding cursor with your mouse and drag
it all the way across to the right. All the monitoring sites should now be visible (incidentally, the slider
is very useful for selecting only sites active between certain dates).
|
Now double-click on the Rivers site labelled K7H1 ![[blue square marker with a black dot]](http://maps.google.com/mapfiles/kml/paddle/blu-circle-lv.png) .
Google Earth zooms into the site and you can use the controls as described in the
Google Earth User Guide to zoom in and out
and pan and tilt the view. |
Check in Google Earth under Tools-> Options-> General that Show results in external browser is ticked,
otherwise the next step produces a rather cluttered map. |
| Single-click on the K7H1 icon and a balloon pops up explaining, sightly cryptically, that this is
K7H001Q01 Bloukrans River At Lottering Forest Res/Blaauw Kr. Click on the graph link in
the balloon: after a short wait, depending on the server and network speeds, a browser window
will open with a PDF graph (or a message that you don't have the free PDF option installed or activated).
The graph is a standard pre-generated time-series of up to 17 water quality indicators, plus flow if available.
On the right-hand side axis are statistical summaries of the data. (Note that the coordinates in the title
area of some graphs may be incorrect because of a conversion error during the latest update of the graphs.) |
| If you would prefer to draw your own graph, return to the balloon and click on the data link. This takes you to a tabular view of the monitoring
points in the region, positioned with the link to the data for site K7H001Q01 at the top of the page. Click
on this "data" link and the system will download k70_102312.zip, which contains the data used to draw the graph.
This two-step process is a workaround because direct links to zip files have so far not worked inside balloons. |
| If you have downloaded the water quality data, you will have noticed that the flow is missing. To get flow data,
click on flow in the balloon. This opens the on-line hydrological database for K7H001 Bloukrans River @ Lotterings For. Res.
Note the different codes used for the same site: the water quality database code is 102312, the full
water quality code is K7H001Q01 and the hydrological code is K7H001. K70_102312 and K7H1 are other
variants used in this browser system. |
| The key link in the balloon takes you to the page
that explains the Maucha salinity symbol that appears in many pop-up balloons.
|
