Impact of soil conservation measures on vegetation recovery in the catchment of a rapidly silting recreational lake at Chandigarh.

Sukhna, a recreational lake developed in 1958 at Chandigarh (North India) by constructing a 12.8 m high earthen dam across three ferocious Shivalik torrents, suffered from pre-mature siltation due to heavy soil erosion from its 4207 ha catchment area. Intensive soil conservation measures were initiated but after 16 years of lake construction which included effective closure imposed by fencing 2540 ha forest area, large scale plantation, construction of more than 180 silt detention earthen dams and equal number of masonry check dams supported by vegetative conservation measures. These measures, carried over a long time, led to vegetation cover development and ecological recovery which formed the subject matter of a comprehensive study conducted during 2008–09 in the catchment of a representative 560 ha micro-watershed. Assessment of vegetation recovery, abundance and species distribution was carried out by physical measurements in plots of different sizes -10000, 100 and 1 sq m for trees, bushes and grasses spread over three landscape regions and slope classes.