Vulnerability and Conservation of Himalayan
Wetlands with Special Reference to Sikkim
Prof. Suresh C. Rai
Department of Geography
Delhi School of Economics
University of Delhi
New Delhi, India
Wetlands are very important and productive ecosystems that support a wide range
of plants and animals and provide livelihood opportunities to local communities.
However, they are increasingly being threatened by rapid urbanisation, developmental interventions, unsustainable management practices, and encroachment. The
Himalayas, with its unique topography and climatic regimes, support diverse
wetland habitats across a range of altitudes. Himalayan high-altitude wetlands
(HAWs) include lakes, ponds, and rivers located at altitudes higher than 3000 masl
and are often fed by glaciers or snow from the surrounding mountains. Sikkim, a
small state in the Eastern Himalaya, has only natural inland wetlands belonging to
the category lakes/ponds. By using data of high resolution, we obtain 1104 glacial
and high-altitude lakes with total area 30.498 km
2 , of which 472 have an area
>0.01 km
2 . Most of it are fed by glaciers and considered sacred.
The hydrology and ecological linkages between Khecheopalri Lake and its
surrounding watershed in Sikkim were investigated to assess the long-term impacts
of land-use/cover change on the hydrology of the lake ecosystem and bog formation
around the glaciated lake. Significant land-use/cover change occurred in the past 4
decades. The bog areas expand by 67%, while the area under agriculture land in the
lake watershed grew by 63% between 1988 and 1997. These changes accelerate the
annual soil loss from the lake watershed which was 502 Mg km
−2 and a net
sediment deposition in the lake was 141 Mg yr
−1 . To conserve the lake, it is
necessary to minimise agricultural practices in the upper part of the watershed, and
agroforestry practices should be encouraged to maintain the health and longevity
of the lake.
xvii
Wetlands with Special Reference to Sikkim
Prof. Suresh C. Rai
Department of Geography
Delhi School of Economics
University of Delhi
New Delhi, India
Wetlands are very important and productive ecosystems that support a wide range
of plants and animals and provide livelihood opportunities to local communities.
However, they are increasingly being threatened by rapid urbanisation, developmental interventions, unsustainable management practices, and encroachment. The
Himalayas, with its unique topography and climatic regimes, support diverse
wetland habitats across a range of altitudes. Himalayan high-altitude wetlands
(HAWs) include lakes, ponds, and rivers located at altitudes higher than 3000 masl
and are often fed by glaciers or snow from the surrounding mountains. Sikkim, a
small state in the Eastern Himalaya, has only natural inland wetlands belonging to
the category lakes/ponds. By using data of high resolution, we obtain 1104 glacial
and high-altitude lakes with total area 30.498 km
2 , of which 472 have an area
>0.01 km
2 . Most of it are fed by glaciers and considered sacred.
The hydrology and ecological linkages between Khecheopalri Lake and its
surrounding watershed in Sikkim were investigated to assess the long-term impacts
of land-use/cover change on the hydrology of the lake ecosystem and bog formation
around the glaciated lake. Significant land-use/cover change occurred in the past 4
decades. The bog areas expand by 67%, while the area under agriculture land in the
lake watershed grew by 63% between 1988 and 1997. These changes accelerate the
annual soil loss from the lake watershed which was 502 Mg km
−2 and a net
sediment deposition in the lake was 141 Mg yr
−1 . To conserve the lake, it is
necessary to minimise agricultural practices in the upper part of the watershed, and
agroforestry practices should be encouraged to maintain the health and longevity
of the lake.
xvii