Multicriteria decision analysis for monitoring ecosystem service function of the Three-River Headwaters region of the Qinghai-Tibet Plateau, China.

The Three-River Headwaters (TRH) region in the Qinghai-Tibet Plateau, China, is of key importance to the ecological security of China and Southeast Asia and contains some of the most sensitive and fragile ecosystems. Monitoring and evaluating the ecosystem service function and its changes in the TRH region could support decision-making for regional ecological protection and restoration programs. Referencing the concept of ecosystem service and the Millennium Ecosystem Assessment (MA) framework, this study built a system of indicators for monitoring and evaluating the ecosystem service function. Thus, combining a multicriteria decision analysis (MCDA) and weighted linear combination (WLC) with analytic hierarchy process (AHP), we applied the ecosystem service function index (ESFI) based on remote sensing data at 1-km spatial resolution to spatiotemporally monitor the changes during the period 2005-2010. The study results indicated that ESFI had a good performance for monitoring the ecosystem service function and showed an improving trend in the TRH region over the past 5 years. Ecosystem environment recovery not only reflected the changing trend of warm and wet climate but was also a response of the ecological protection project of the Key Ecological Function Zone in the TRH region.