An evaluation of ecological losses from hydropower development in Tibet

As an important and typical human activity, hydropower development provides a source of energy as well as socioeconomic benefits; however, it inevitably damages or even destroys the ecosystem at different spatial scales - the plant scale, the river scale, and the watershed scale. In this paper, a multi-scale evaluation method is proposed for placing a monetary value on ecological losses at these three spatial scales due to hydropower development in Tibet. At the plant scale, ecological losses are defined as the damage caused by environmental pollution and ecological destruction, and it is suggested that they can be almost completely prevented if appropriate measures are taken. The ecological losses at the river and watershed scales are defined as alteration of the ecosystem structure and deterioration of ecosystem function, and even the most efficient protective measures usually cannot completely avoid such losses. To test the results of these evaluations and determine whether they are consistent with actual losses, case studies of hydropower projects in Tibet were carried out on 5 large hydropower projects (LHP) and 10 small hydropower projects (SHP). For the SHP, a correlation is suggested between the estimated ecological losses caused by each project, and its installed capacity and electricity production. The results tested well for predicting the ecological loss for SHP, and provide a referenced norm for policy-makers for hydropower development in Tibet.