Of the Mountains and the Rivers
One of the most interesting thing about the Himalayas is how the Rivers interact with the Range and how the River Basins work. Since none of us is taught this in school in the Geography class the way one can study this fascinating aspect is to study Maps. Not the Maps of the new but the old Maps made by the Geological Surveys and the Royal Geographic Society Maps. The kind of detailing in these Maps is amazing when we keep in mind the fact that it was all done by boots on the Ground. No Aerial or Satellite Cartography.
And I finally found a Map which shows the River Basins / the Mountains / the Ridgelines / the Water Partings in a very simple and lucid fashion. Of course there are some explanations required for the un-initiated in the fine art of reading Maps. Not only does it show the Water Basins in the Himalayan context but it also shows the neighbouring River basins and how the Mountains affect the Course of the Rivers. You also need to understand that its this conflict between the Rivers and Mountains which has created the Valleys which has enabled Human communities to inhabit the Mountains.
In the Himalayan context the Three main Rivers which drain the Himalayas are the Indus in the West, the Ganges in the Middle and the Brahmaputra in the East. It is common knowledge that the Indus and the Brahmaputra which rise from almost the same vicinity of each other near the Mansarovar Lake in the Tibetan Plateau hem in the Great Himalayan Range from the opposite sides. The Indus forms the boundary on the West as it passes by the Nanga Parbat and the Brahmaputra forms the boundary on the East and it rounds off the Namcha Barwa in the East. The Indus and the Brahmaputra both never breach the Main Himalayan Ridgeline and run alongside but behind the Main Himalayan Ridgeline on the Tibetan Plateau. Both flow along what Geologists call the Indus Tsangpo Suture or divide in simpler terms. I would also like to mention one major River which actually cuts through the main Himalayan Ridge line and forms the Eastern boundary of the Western Himalayas. This would be the Satluj which coincidentally also originates around the same area as the Indus and the Brahmaputra (which is called Tsangpo in Tibet) and follows an independent course cutting through the Himalayas though it finally ends up in the Indus once it reaches the Great Plains of the Punjab.
Beyond the Basins of the Himalayan Rivers we have in the neighbourhood the Tibetan Basin though a part of the Tibetan Plateau is drained by these Himalayan Rivers themselves. Further North the main Ridge line of the Karakorams forms the Water Parting between the Himalayan Rivers (the Indus system) and the Tarim Basin. The Tarim Basin is itself separated from the Tibetan Basin by the Kunlun Mountains. To the West of the Tarim Basin separated by the Pamirs in the South and the Tian Shan in the North is the Central Asian basin of the Oxus and Jaxartes of the old. The names Oxus and Jaxartes were enough in the old times to induce Explorers to go into a frenzy so inaccessible these areas were. However nowadays the Oxus and Jaxartes are better known by their present names, the Amur Darya and the Syr Darya. On the southern Edge the Oxus and Jaxartes Basin is separated from the Himalayan River Basin by the Hindu Kush. Further down the sub Ranges of the Hindu Kush like the Sulaiman Mountains divides the Himalayan River Basin from the Helmand River Basin. This rounds off the Water Partings of the Indus in the Western Himalayas.
If you follow the Indus River in the Map you would see that after the point of origin the Main Waterparting of the Rivers runs behind the Main Himalayan Range rather than along the Main Ridge as classically should be the case. However at the point roughly at where it enters Ladakh from the Tibetan Plateau the River aligns itself with the Main Himalayan Range and continues the same course all the way to the Nanga Parbat where the Great Himalayan Range ends. The Water Parting however moves North towards the Karakorams and even across the Karakorams as seen in zone H. Close to the K2 however the Water Parting again moves along the main Himalayan Ridge line. But then after following the Main Ridge line of the Karakoram to West it again goes beyond the Karakorams as seen in zone C. It continues this trend until its behind the main Ridgeline of the Hindu Kush till at a point beyond the Tirich Mir it again aligns with the Main Ridge line to deviate again to form Zone B all the way to the Helmand Basin.
In pretty much the same way the Water Parting of the Tarim Basin also jumps beyond the Kun Lun, the Pamirs and the Tian Shans at places but it doesn't jump the main Ridge Line of the Karakorams as the reigning Peak of the K2 brings in a semblance of order and the Water Partings follow the K2 in the classical mode (I know this is complicated but once you co-relate with the Map and do some readings it will become more fascinating). Interestingly in the Hindu Kush its the highest Peak of the Hindu Kush the Tirich Mir which forces the Water Parting to run along the main Ridge line just like its supposed to be classically. However a point to be noted is that the Indus never concedes any of its “Mountains” the Western Himalayas or the Karakorams or the Hindu Kush to any River though itself it pushes its Basinal boundaries to well into the Kun Luns, the Pamirs and the Tian Shans though not quite making it to the main Ridge line.
And of course as we all the Mountains are rising and the Rivers are just cutting the Gorges and the Valleys and this state of flux will continue over a period of time till the end of time. And because of this constant change the Water Partings are not as fixed or permanent as we would like to believe. They are also constantly changing and evolving in a Geological time frame. This also shows how the Rivers and the Basind connect these highest Mountains in the World in a closer relationship than we actually believe. The River and the Basins provide the linkages which connect the Himalayas with the Karakorams, the Hindu Kush, the Kun Lun, the Pamirs and the Tian Shans. I collectively like to use the term “Himalayas” when talking about all these Ranges and the Great Himalayan Range when I am referring to the Main Himalaya Range. The highest Range on the Planet.
May we one day get to behold the magnificent sights that these Mountains hold and their mighty Peaks. And may we one day get to drink water from all these Rivers. The transition zones between these Himalayas is probably even today one of the most least explored in the World and they continue to hold their Mysteries, occasionally revealing them to us mere Mortals.