资源环境科技发展态势分析平台

Precipitation plays an essential role in hydrological cycle, water resource availability, and ecological economics sustainable development both within the Qilian Mountains (QM) and its surrounding. On the basis of meteorological station records and reanalysis data sets, we investigate the variations of precipitation in the QM during 1960-2014 and their connection to the shifts of regional atmospheric water vapour. Results show that precipitation in the QM as a whole has experienced pronounced wetting at an annual rate of 6.95 mm/decade. Significant (at 95% confidence level) precipitation increase mainly occurs in JJA (June-August) and slightly in DJF (December-February). The evident increase of precipitation appears in the mid-east of the QM. Furthermore, the increasing rates of annual, JJA, and SON (September-November) precipitation increase with elevation, indicating obvious elevation-dependent precipitation increase in the QM. The atmospheric precipitable water (PW) for annual, JJA, and SON time series over the targeted region generally shows significant increasing trends, especially during 1979-2014. The meridional and zonal water vapour budgets positively and negatively contribute to the regional net water vapour budget, respectively. Moreover, we demonstrate that the zonal water vapour budgets are strongly intensified and meanwhile the meridional ones except in transitional seasons are weakened. Thus, regional net water vapour budgets for annual and seasonal time series are increased. All in all, the shifts of the regional atmospheric water vapour, such as the increases of PW and water vapour budget (referring to the zonal and regional net water vapour budgets), agree with the result that the QM precipitation increases from 1960 to 2014, which suggests the QM wetting trend is in connection with the changes of the atmospheric water vapour.