The spatio-temporal variability of annual precipitation and its local impact factors during 1724-2010 in Beijing, China

Rapid population growth and increased economic activity impose an urgent challenge on the sustainability of water resources in Beijing. Understanding the spatial and temporal variability of precipitation is of the upmost importance in order to sustain the region's water resources. Two time series, one long term (1724-2010) from a single meteorological station and a shorter time series (1980-2010) from 20 different meteorological stations within the Beijing area, were analysed using Linear Regression, Moving Average, Mann-Kendall, Rescaled Range and Spatial Interpolation methods. Results from both the long- and short-term meteorological data show a mean annual precipitation rate of 600mm and 540mm respectively. Annual precipitation rates have decreased during the 21st century by an estimated 100mm or 16% in comparison to the 1990s. The 1980-2010 data show an increase in precipitation during the early 1990s followed by a sharp decrease during the subsequent years. The change of annual precipitation with time is more random and diverse in comparison to space. The main local impact factors (terrain, urbanization and elevation) and how they work on the local precipitation especially the spatial diversity are identified qualitatively. Generally speaking, (1) the annual precipitation of the plain area is more than that of the mountainous area (terrain effect), (2) the annual precipitation of the urban area in the plain area is obviously more than that of the surrounding suburb area (urbanization effect) and (3) the annual precipitation of the lower location is approximately more than that of the higher location (elevation effect). Copyright (c) 2013 John Wiley & Sons, Ltd.