Evaluating ecological vulnerability over Qinghai-Tibetan Plateau based on remote sensing and geographic information systems

Qinghai-Tibetan Plateau (QTP), known as “the Third Pole”, has one of the most fragile ecosystems in the world. QTP is suffering from external pressures of climate change, human activities, and natural hazards. This study provides a subjective framework in assessing ecological vulnerability (EV) in QTP from 2000 to 2015 based on remote sensing and geographic information system techniques. An ecological vulnerability index (EVI) was established based on 17 indicators mainly acquired from satellite data. Principle component analysis and entropy method were used in determining indicator weights. Annual EVI were calculated based on the weighted sum of all indicators. Five vulnerability levels of potential, light, moderate, heavy and very heavy were graded to describe the spatial and temporal patterns of EVIs. Mann-Kendall trend analysis was performed over QTP during the 16 years. Results indicates QTP is suffering from an overall increasing EVI from eastern to western areas. About 10.43% of QTP has experienced significant EVI decrease, while 7.38% experienced significant increase in EVI.