Precipitation trend–Elevation relationship in arid regions of the China

• In this study, we investigated that the regional characteristics of precipitation trend and the precipitation trend–elevation relationship in the arid regions of the China (ARC).
• There is growing evidence that the elevation-dependent wetting (EDWE), which is the precipitation wetting trend is amplified with elevation.
• In this study, we discuss mechanisms that contribute towards EDWE: water vapor changes and warming-driven water circulation speeds up.

Based on monthly precipitation data at 128 meteorological stations in the arid regions of the China (ARC), we investigated that the regional characteristics of precipitation trend and the precipitation trend–elevation relationship during the period of 1961–2012. There is growing evidence that the elevation-dependent wetting (EDWE), which is the precipitation wetting trend is amplified with elevation. The precipitation trend increases significantly with elevation except for the altitude from 500 to 1500 m, the highest correlation appears above 1500 m, increases by 13 mm/decade with each 1000 m. With the elevation increasing every 1000 m, precipitation tendency rate increases by 7 mm/decade from 1000 to 2000 m and increases by 10 mm/decade from 2000 to 4000 m. EDWE has an impact on the change of the cryospheric systems, ecosystems and water resources, especially in arid regions of China. We discuss mechanisms that contribute towards EDWE: water vapor changes and warming-driven water circulation speeds up. We suggest future needs to increase evidence of understand the EDWE in other mountainous regions, and its controlling mechanisms through integrated the observational network of surface in-situ climate observations, satellite data and high-resolution climatic modeling.