Abstract: The Ruoergai Plateau has an important function in water conservation. In this study, water conservation was simulated using water balance method based on meteorological and remote sensing data. We analyzed the spatiotemporal changes of water conservation function and its influencing factors in Ruoergai Plateau during the period 2001-2017. Results showed that the amount of water conservation (AWC) varied greatly, gradually increasing from the north to the south. During the study period, the proportions of the AWC per unit area <100, 100-200, 200-300, 300-400, 400-500 and >500 mm were 15.43%, 63.66%, 18.66%, 2.22%, 0.03% and 0,respectively. The average AWC in different regions was following the order of Aba Tibetan and Qiang Autonomous Prefecture > Hongyuan County > Rouergai County > Maqu County > Luqu County. The average AWC per unit area in the Ruoergai Plateau showed a slight upward trend. The proportions of the areas with significant decrease, moderate decrease, slight decrease, almost constant, slight increase, moderate increase and significant increase in water conservation were 50.64%, 16.81%, 11.64%, 5.20%, 4.52%, 7.31% and 3.88%, respectively. The AWCs in Aba Tibetan and Qiang Autonomous Prefecture and Rouergai County showed an increasing trend, while the other three counties (Maqu, Luqu, and Hongyuan) showed a decreasing trend during 2001-2017. Precipitation and elevation were the major factors driving spatiotemporal changes of water conservation function.

Key words: Ruoergai Plateau, water conservation, water balance, spatiotemporal characteristics.