当前世界环境

The Kashmir Himalayan valley witnessed some unique environmental pollution phenomena including black snow and outbreak of red-tide in lacustrine systems during early 1991. The occurrence of a rare muddy snowfall in May 2002 on high altitude (>4300 m.asl) Afarwat glaciers in the alpine zone (near Gulmarg) of Pir Panjal mountainous range of the Kashmir Himalaya indicates changing environmental scenario of the region. The principal hydrochemistry of the snow samples collected from the glacier revealed relatively high pH values (6.2-6.9) as compared to low records (pH;5.6) in snow samples of the valley-floor (alt.1600 m). The ionic composition showed relatively high values (u eq L-1) of chloride (12), carbonates (20), bicarbonates (36) and silicates (19) in the top-most layer of the glacier whilst dissolved oxygen and dissolved organic matter were below detection levels. On the contrary, low levels of nitrate (3.3 u eq L-1) and ammonical-nitrogen (2.8 u eq L-1) were recorded in glacier snow samples compared to valley-floor samples. The comparison with published works from other regions of the world indicates that the ionic concentration is higher in the glacier snow of the Kashmir Himalaya.