Land use/cover change and environmental vulnerability analysis in Birahi Ganga sub-watershed of the Garhwal Himalaya, India

Abstract

The study analyses the land use/cover changes and environmental vulnerability of the Birahi Ganga sub-watershed in the Garhwal Hi malaya, India. Satellite data of 1976, 1990 and 2005 shows that dense forest area increase d from 1976 to 1990, which showed decreasing trend in the period 1990 to 2005; howeve r, overall the results showed a net increase in the dense forest from 1976 to 2005. Contrary to this, grassland area declined in the initial period but increased between 1990 and 2005. Increas e in agricultural land area was observed all through, whereas open forest and riverbed areas decreased. Spatial Principle Component Analysis (SPCA) showed that the environmental vulne rability initially decreased in the period 1976 to 1990, which then increased during the perio d1990 to 2005. Most vulnerable areas were those on the warmer aspects, steep slopes and lower elevations. In these vulnerable sites land use/cover changes correlated with high human interf erence such as increased agricultural encroachment, forest resources extraction and grazi ng. Our observation shows that the human activities have increased recently in higher elevat ions as a response to increased population pressure. Related policies could be the underlying driving forces of the changes