Abstract

The siltation rate in the Lake Wular, one of the largest fresh water lakes in Asia, shows abnormality in space and time, as evidenced from the preliminary geological survey of its catchment. The Panjal traps and limestones (with scanty intercalations of black shales) form the major provenance for the silt which drains into the lake. The lineament fabric suggests a strong structural control over the formation of the lake. The Tertiary uplift, as well as, the pulses of seismicity have been instrumental towards the modification of regional geomorphological relief and the resultant changes in the rate of siltation. The climatic changes have also been influential in the varied rate of erosion and subsequent siltation rates. The valley of Kashmir, sheltered from the south-west monsoon by the Panjal range, has not the periodical rains of India. Its rainfall is irregular, greatest in the spring months. Occasional storms in the monsoon pass over the crests of the Panjal and give heavy rain on the elevated plateaus on the Kashmir side, being the main agent of erosion along the topography of the Wular lake. Also, the clouds passing over the valley are arrested by the higher hills on the north-east side, bringing torrential rains. These impacts have been further accelerated due to deforestation in the much fragile, mountainous topography of Wular. The topographic relief thus appears to have fluctuated in the recent geological past, as is evidenced from the silt deposits in and around the lake. The environmental significance lies in the fact that such a rate of siltation would result in shallowing of the lake floor and may prove disastrous during higher degrees of run off, either due to excess precipitation or melting of ice. The present state of human interference, in the form of settlements around the lake and farming practices on the reclaimed and / or acquired land of the lake, are beyond permissible limits of the environmentally safety zones.