One of the largest freshwater lakes in India, cradled in the tectonic basin of the Kashmir Valley.
Wular is one of the largest freshwater lakes in India, spread across the low floor of the Kashmir Valley in the north of the valley, with the Jhelum river flowing through it.
At heart it is a floodplain lake. The Jhelum, the valley’s main river, slows and spreads where the land is flattest and lowest, and Wular is the great natural hollow where that water pools. It works as the valley’s flood absorber, swelling during the melt and rainy season and letting the water back out slowly.
The lake sits on the floor of something far bigger. The Kashmir Valley is an intermontane basin, a low trough caught between two rising mountain walls: the Pir Panjal to the southwest and the Greater Himalaya and Zanskar ranges to the northeast. As those ranges were pushed up by the ongoing collision of India and Asia, the block of crust between them sagged and dropped. That sinking floor dammed the valley’s drainage and, through the ice-age Pleistocene, held a very large lake, the ancestral Karewa Lake.
That old lake lasted a long time and filled steadily with fine sediment, layer upon layer of clay, silt and sand, in places hundreds of metres to more than a kilometre thick. When the natural barrier finally gave way and the great lake drained, those flat-lying beds were left exposed, then uplifted and gently tilted into the flat-topped terraces called Karewas that flank the valley today. Wular is, in a sense, a shrunken survivor of that vanished lake: open water still standing where the valley floor lies low enough to pond the Jhelum.
The same tectonic basin that made room for the lake keeps feeding it sediment. Streams strip material off the Panjal Trap lavas, limestones and Karewa beds in the surrounding catchment and dump it into Wular, which is exactly why the lake naturally silts up over time. In the last century that silting, together with encroachment, has shrunk it markedly, and it is now a protected Ramsar wetland fringed by marsh and floating gardens. Wular is the low point of a slowly sinking, sediment-filled tectonic basin. The collision that raised the surrounding mountains also created the hollow between them, and the lake is what still stands in the deepest part of that hollow.
Sources
- Ramsar Convention
- Tectono-geomorphic study of the Karewa Basin of Kashmir Valley, NW Himalaya
- The Vale of Kashmir: Landform Evolution and Processes (in Landscapes and Landforms of India)
- Mineral Magnetic and Geochemical Mapping of the Wular Lake Sediments, Kashmir Valley, NW Himalaya (2019)