Riverine nitrogen loss in the Tibetan Plateau and potential impacts of climate change.

The Tibetan Plateau (TP) has been the subject of study on water circulation and global climate change. Given the environmental processes related to water outflows, there could be massive nutrient losses in the land surface of TP. In this study, we analyzed the nitrogen discharges of the major rivers flowing out of the TP based on the 5-year monitoring data. According to our calculation, the majority of nitrogen outflows were discharged through the upper Yangtze River and upper Huanghe River, representing ~29% and ~17% of total riverine outflows, respectively. In the entire nitrogen deficit in TP land surface, about 2.7 × 10(5)Mg/year was lost through riverine discharges. Due to the global warming, the changes of hydrologic processes in TP would possibly accelerate the riverine nitrogen outflows in the future.