Talk:Orange River

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[edit] Linking to main articles

Hi, When I have to refer to a subject that is covered by an existing article I have come to like using a short introduction to the subject and then refering to the main article in that introduction. Then I learnt how to use:

Main article: Lesotho Highlands Water Project

now I see it has been undone.. Please advise.. Gregorydavid 16:16, 26 April 2006 (UTC)

[edit] Crocodiles

Where did the information about the Orange River being too far South and therefore too cold in winter to support crocodiles? I'm rather dubious of this. The upper reaches of the river would certainly seem too cold to support crocodiles, but I find it difficult to believe that it is too cold for them in the lower reaches, such as the section that forms the border between South Africa and Namibia. After all, crocodiles thrive so well they are farmed commercialy hundreds of kilometres South of here in the southern Cape.

Beefart says: Crocodiles are indeed absent from the Orange River. Sad but true. I have swum in it from end to end and I wasn't eaten once! :) :) :).... Tables and diagrams at www.cites.org/common/cop/13/raw_props/NA-crocodile.pdf confirm that the reptile is not found in the Orange. It can be very cool on the lower reaches of the river in winter. Anyone who has spent a night at Vioolsdrif in August will testify to how nippy it can get. The best I can offer you is a likkewaan. My mother was chased by a likkewaan on the banks of the river in Upington but she escaped... I'd be interested to know whether the crocodiles being bred in the southern Cape are given a hot water bottle or a dop of brandy at night in winter. My research also shows that there is less salt in the Sout Rivier than there used to be, that the olifante have all fled from the Olifants Rivier and that there really never was a witch in the Hex River....Captainbeefart 01:58, 6 June 2006 (UTC)

Good research, I've not been up to that part of the world. The crocodiles I saw in the southern Cape were near George and Oudtshoorn. I'm not sure how they spent the winter, but animals in captivity do have a wider tolerance range than those in the wild.

[edit] Renaming names and Politikal Korektniz

Why does Zaian consider my aside to be "gratuitous"? Is he suggesting that the renaming of the dams was not politically motivated? Or does he label as "political" (and delete) those remarks of which he does not approve? Why not go the whole hog and delete the (political) observation that the names of the dams were changed? Few would notice the omission. I don't really care what the dams are called. I don't worry too much that history in South Africa is being rewritten. It is human nature to do so. To the victor the spoils. (For what it is worth, I grew up in the time of Verwoerd and loathed the man). But I draw the line at trying to kid myself that it isn't happening... P.S. Somebody might add the new names. I don't know them.Captainbeefart 12:05, 6 June 2006 (UTC)

Hmm, I seem to stand accused of something. It seemed a pretty gratuitous link to me. PS The new names are already there in the previous sentence. Zaian 15:53, 6 June 2006 (UTC)

[edit] Indiginous people

I do not think it is Eurocentric to state a date when Europeans first climbed Table Mountain or explored the Orange River. Are we going to edit all the articles from Cape to China to note rather vaguely that the indigenous populations all got there first? Gregorydavid 00:41, 20 March 2007 (UTC)

[edit] Catchment contradiction

In the text of the article it says that part of the Orange River's catchment is located in Botswana, however the map of the catchment does not show the catchment extending into Botswana. I'm of the opinion that the map is correct.

On a slightly different matter I don't think it is wrong to give details of when a place or feature was first explored by Europeans or indeed by any other people with a written history (eg the Chinese, Arabs etc). Palatable or not, the history of Southern Africa began with European exploration/colonisation as the inhabitants before then had no written history. Booshank 14:52, 24 August 2007 (UTC)

As common with rivers in arid regions it is difficult to decide about the actual watershed. There is no permanent river in that region so the actual drainage is subject to seasonal (or even less frequent) variations and most of the precipitation will not result in far reaching runoff. The map draws a conservative border of the drainage basin and i do not have any reliable sources for a different watershed line further north. Note the maps that can be found in the article links show a larger area extending much into the Kalahari Desert while in the one in Drainage basin more or less matches mine. Imagico 18:23, 27 August 2007 (UTC)
The map included and displayed in the body of the article is incorrect. This: Map of portion of Orange River basin forming part of South Africa shows clearly that an area of catchment exists east of the 20 degree longitude border with Namibia and that the catchment extends eastwards into Botswana and north of South Africa into Botswana over those tributaries which appear to exist on the South African Botswana border.Gregorydavid 06:14, 28 August 2007 (UTC)
In fact this one Map of the Orange River basin at Water Resources eAtlas leaves nothing to the imagination. The map displayed in the article will have to be corrected...Gregorydavid 14:34, 28 August 2007 (UTC)
All right - i thought my point was clear and not necessary to provide further proofs but here you go. Citing from: C. J. Swanevelder: Utilising South Africa's largest river: The physiographic background to the Orange River scheme (GeoJournal Supplementary Issue 2 (1981), p. 29-40, http://dx.doi.org/10.1007/BF00196322 - no free availability):

"... Further to the west lies the sand-filled basin of the Kalahari with its Molopo, Kuruman and Nossob river systems joining to form the lower Molopo, which drained into the Orange along the old Hygap course during the pluvials of the Pleistocene. Subsequently the lower course of the river was blocked by windblown sand and at present the lower Molopo, when flowing, is diverted into Abiquas Puts (Wellington, 1958, p. 5) causing the Kalahari drainage basin to become endoreic. The Kalahari is therefore excluded from the Orange River drainage basin in this study."

Some freely accessible information can be found in http://www.egs.uct.ac.za/sagj/Bootsman79(2).htm. I think this not only makes it reasonable to decide on the conservative watershed like explained, it also makes quite clear that drawing the extended drainage area as done in those other maps is actually incorrect by any definition of the the term. Imagico 18:53, 29 August 2007 (UTC)
The above is what I believed. I think the problem is that many individuals in this field are used to more humid climates such as those of Europe and much of North America where watersheds can be drawn purely using topographical information. That map showing much of the Kalahari and south eastern Namibia draining into the Orange River looks as though it was drawn by a computer based purely on where water would drain because of topography, regardless of whether it does actually. Taken to the ultimate conclusion, one could by this method draw up a map of the River Jordan flowing into the Gulf of Aqaba. My maps of Southern Africa certainly show the Molopo, Kuruman, Nossob and Auob as intermittent streams flowing into Abiquas Puts south west of Witdraai, just east of the Namibia-South Africa border and about 100 km north of the Orange River. Booshank 17:07, 31 August 2007 (UTC)


Incidentally, there is some information on generation of the maps linked to above by Gregorydavid here and here respectively. They use different software, but I don't know enough about GIS to assess its quality. Imagico, could you perhaps clarify the technique(s) you used to derive the watershed in the map, and maybe compare it/them to those used in the maps Gregorydavid cites? -Kieran 23:09, 11 September 2007 (UTC)
The first of the links you gave does not give any information of the actual technique for determining the watershed and the second says it uses elevation data (GTOPO30, http://edc.usgs.gov/products/elevation/gtopo30/gtopo30.html). Quality of this data varies but it is unlikely that considering the low height differences in the region in question it can hardly be used to reliably determine the watershed there. In any case using purely elevation data means the results refer to the hypothetical waterflow and not necessary actual drainage.
For creating the map i used the VMAP0 river and water area layers. These commonly include major non-permanent rivers and there is clearly no connection between Molopo and Orange according to this data. Imagico 08:54, 12 September 2007 (UTC)

[edit] Countries in the infobox

Just to clarify, Template:Geobox_River states that the country field is for countries which the river flows through. As such, I've removed Botswana. Whether or not the river's catchment includes Botswana, it most certainly does not run through the country. -Kieran 22:22, 11 September 2007 (UTC)

[edit] Removal of catchment map

The catchment and course map was removed by Gregorydavid. Regardless of the debate on the catchment area of the river, that map is the only one we have showing the river's course, so I have restored it. I have also expanded the caption to explain the ambiguity regarding the inclusion of the Kalahari as part of the catchment, as has been debated above. -Kieran 22:25, 11 September 2007 (UTC)

Thank you, I actually needed that! (unsigned) —Preceding unsigned comment added by 74.183.138.133 (talk) 01:18, 12 February 2008 (UTC)

[edit] Conservative catchment

One can understand hydrologists excluding parts of a catchment that make a negligible contribution to the potential abstraction from a river system. What is the name and extent of the catchment adjacent and to the north of the conservative Orange River catchment? Do large pans that rarely fill up to the extent that they overflow into the river system automatically qualify for exclusion from catchments? Can areas that yeild no runoff be classified as black holes? Gregorydavid 11:24, 14 September 2007 (UTC)

Drainage basins are often not clearly defined in arid regions. When the climate is humid water not absorbed by the soil runs downhill and local depressions fill with water until an outflow is formed. But when evaporation usually exceeds precipitation very small endorheic regions can exist. The larger region north of the Orange River is the Kalahari Basin but it does not form a drainage basin as a whole. Part of it is the Molopo river basin and it probably borders to the Orange river watershed in some parts but there are very likely also other separate endorheic basins.
Note by the way there are other interesting drainage basin cases. The Kherlen River watershed for example usually is an endorheic basin but occasionally will form a tributary of the Argun and Amur River. The situation here is different though since according to the sources the Orange River has permanently ceased to receive water from the area in question a long time ago. Imagico 15:58, 14 September 2007 (UTC)

[edit] Namibia in the Geobox

There was a reason I originally excluded Namibia from the box. That is that, according to one source I read, there is currently a border dispute between Namibia and South Africa over the river. Apparently the standard for rivers forming national boundaries is for the boundary to be in the middle of the river. However, according to the treaty that set the Orange as a border, South Africa owns everything up to the north bank. Thus, technically speaking, the river does not run through Namibia, although it comes as close as it possibly could to doing so without actually doing it.

I don't have the source on hand, but I can get hold of it. I'm not sure what the best thing would be, though: Technically the infobox is supposed to contain only countries that the river runs through. Discussion welcome.-Kieran 23:34, 16 September 2007 (UTC)

I would have preferred a definition which allowed the inclusion of all countries in which major tributaries occur.Gregorydavid 09:23, 17 September 2007 (UTC)
I think, if they are major tributaries, they would deserve an article of their own. For example, if we were to put in the provinces the Orange flows through, it would be strange to include Gauteng, which the Vaal does flow through (and form the border of). However, the Vaal is (or should be) listed as a tributary, so the information is there. -Kieran 23:18, 18 September 2007 (UTC)
There are major tributaries and they do have articles of their own, eg Fish River (Namibia) which in my opinion qualifies Namibia for the Geobox. How does this apply to Botswana?Gregorydavid 08:50, 19 September 2007 (UTC)