Impact assessment of a hydroelectric project on the flora in the Western Himalayan region based on vegetation analysis and socio-economic studies

Abstract

This study provides an overview of the impacts of a proposed hydroelectric power project in the Western Himalayan region in India, using a primary database on floristic diversity and vegetation analysis. The remote sensing data revealed that in the submergence zone only mixed deciduous forest that occupies 807.5 ha area and has a wood biomass volume of 4,027,503 m³ is likely to be lost due to impoundment. A total of 165 plant species found in the submergence zone also occur in the influence and free draining catchment area of the project. In the influence zone of the project area only one tree species (Acer oblongum) is found under conservation threat category, which is also present in the free draining catchment of the project. The project affected population (6716 people) residing in the submergence and influence zone depend upon the surrounding forests for fuel wood, fodder, wild edibles etc., and most likely they will settle in the nearby areas, thus mounting more pressure on residual forests of the influence zone for various forest products. Further, from the vegetation analysis it is evident that several tree species (e.g. Lannea coromandelica, Terminalia alata, T. bellerica etc.), may face more pressure from exploitation as they provide a number of useful products and are represented in lower numbers in the forests of the project area. To compensate for the loss of various goods and services provided by the forests falling in the submergence zone and to offset the increased pressure of the project affected families on the forests of influence zone, a biodiversity management plan is suggested incorporating socio-economic considerations.

Keywords:

• conservation status
• community dependence
• hydropower potential
• forest type
• environmental impacts
• submergence zone, Western Himalaya

Acknowledgements

The authors wish to express sincere thanks to M/s National Hydroelectric Power Corporation Ltd., Faridabad, India for providing the opportunity to work on EIA/EMP studies of the proposed project. Several officials of NHPC provided greater insight to the project and the authors thank them all, in particular Ers Ramesh Chandra, ED (Uttarakhand) and B.D. Saraf, GM (Planning), Drs (Mrs) Usha Bhatt and V.K. Bahuguna, Chief (Env), and Er K.D. Sah, Chief Engineer (I/c) for their valuable support in undertaking the assignment. Special thanks are due to the Director, G B Pant Institute of Himalayan Environment and Development for his continued support and encouragement during the course of the study. Finally, the authors wish to thank all their colleagues who directly or indirectly rendered help from time to time.