Potential risk to water resources under eco-restoration policy and global change in the Tibetan Plateau

Abstract

Water shortage is a core problem that has hindered sustainable development worldwide. The Tibetan Plateau feeds ten main rivers on which almost 20% of the world’s population depends. However, the plateau has suffered serious environmental deterioration from global warming. Since the 1980s, the Chinese government has supported ecological restoration in the Tibetan Plateau, mainly by promoting large-scale afforestation and grassland conservation. To identify the impact of global change and ecological restoration policy on the plateau, we used geographic information system (GIS) methodologies to study changes to the water supplies in the region as a result of implemented restoration programs. Moreover, we also used GIS to assess the potential risks of these changes for the long-term sustainability of water supplies. Our findings show that the quantity of water supplies in the Tibetan Plateau has increased over the last 36 years; this was attributed to an increase in precipitation as well as increasing glacial meltwater due to global warming. We also found that the water consumption associated with afforestation projects reduced the water yield, in that it was altered by the artificial establishment of plant communities, with different afforestation projects variously impacting water consumption. The potential risk areas in the plateau were mainly distributed in areas with dense human populations and villages, and intensive human activities around forest shrubs where ecological restoration programs had been largely implemented. We highlight the need for ecosystem management and monitoring within larger afforestation programs, which should include the planting of vegetation with low rates of water consumption.